Celidor

Others have talked about fuel economy in other threads but I couldn't find any answer to my issue. I recently purchased an 09 SV with 96k kilometers.. That's around 60k miles.

I have been getting excellent city fuel economy about 8-9l/100km (29-26mpg) and when driving at night with less traffic and more 60-80km roads I can get about 7.4l/100km (32mpg).
This better than I expected to get with a 3.5L 290hp, 261 torque engine, and better than what I have read others getting on the net.

The problem comes on the freeway. The fuel usage, according to the built in fuel meter thingy, is not very consistent here. I have tried cruise control at 100km (62mph) and it has got me anywhere from 11.8l/100 to 7.7 (20-30mpg) and the sound of the engine is matching the fuel meter so it's not like it is being inacurrate. I've driven faster and that more often than not will improve it slightly. I know how to drive to maximize fuel economy but it feels like something must be wrong for the car to be getting such bad fuel economy on the highway.

The strangest thing is how it will at times drive as expected and gets 30mpg at 100kph and other times if I don't speed it up to 110kph (70mph) it will be getting closer to 20mpg at 100kph. I thought faster would use more gas! It's terribly inconsistent and I know hills will affect mpg greatly.

So does anyone know what might be causing this problem? I checked tire inflation already. Oil and filter are only a week old. I do have winter tires on as that is all i have for the car at the moment, but I would think that their affect on fuel would be more consistent. I've only ever filled it with 91octane.

In my 4spd 98 v6 accord I could get 8.3l/100km (28mpg) on the highway, and that was a 4spd. I was expecting better highway from this car and worse city. I'm confused!

Celidor

So what part of the car do people think I should be looking at for a problem?

Ghozt

dont use the live meter to calculate your mileage, track your mileage and do the math when you fill up.

Celidor

I do calculate with the trip meter and the volume of fuel needed to fill the tank as well as using the live economy meter but I would need to drive on the highway only, with a fresh full tank and then refill the tank right after, and I haven't had the opportunity yet.

I have been assuming the live meter would still be fairly accurate. I'm talking a 50% increase in fuel consumption at different times when going 100kph. I don't know how much of an affect winter tires can have. I've been speculating that the transmission may be the culprit. I've heard people saying that the car will learn your driving habits/style. So maybe I need to do a full reset.

My engine also doesn't sit at idle as nicely as I suspect it should. After its all warmed up it still won't sit at 600rpm for long before dropping down a bit and revving up and causing vibration.

I want my baby to purr like new. I know I need to give it a tune-up but I never have before and don't want to pay a mechanic to do it.

Here's what I'm thinking to do to hopefully fix the issues:
Change spark plugs, new air filter, change transmission fluid, and fill with synthetic.

Would a dirty throttle body cause any of the issues I'm having? Am I missing something important that may be causing this?

Any help would be appreciated.

(Hey Ghozt, I like your halos and those lights you have in the left and right air intakes, very cool. Once I get my car running smoother I have questions about that. I'd love to half some cool looking lights to take the place of DRLs.)

lightonthehill

Cruise control does not give optimum fuel efficiency. In fact, unless the area is perfectly flat, cruise control lowers fuel efficiency by several MPG. Cruise control does not allow the car to use gravity to pick up 'free' momentum on downgrades, and raises the RPMs (less fuel efficient) in order to unnecessarily maintain exact set speed on climbs. It also fails to make slight speed adjustments that would allow smother interface with traffic conditions.

27 to 30MPG is the normal freeway fuel efficiency most posters here have been getting with the 7th gen these last four years. Once in a while, we have someone get over 30, but that is the exception.

The fuel efficiency gauges in the car are not very useful to me. The 'current MPG' reading is especially meaningless, because it pegs the top of the MPG meter on downgrades and drops to single digits when climbing steep grades. I totally ignore it. I keep a long-running log of fuel put in the car and miles driven, which gives me a good overall feel for my fuel efficiency.

I normally get between 17 and 22 MPG in city driving, between 22 and 25 MPG in suburban driving, between 25 and 27 on non-freeway highway driving, and between 27 and 30 on interstate/freeway driving. But many factors, such as driving style, are involved.

I suspect you may have some type of guage problem. Nobody here on the ORG is getting anywhere near 26 to 29 MPG in true city driving. I would suggest you take the time to record your odometer and fuel put in the car at each fillup. To get any kind of accurate reading requires this be done over times with lots of fillups. I listed 46 variables somewhere here on the ORG back around 2005 or so that could prevent an accurate measurement when using just one or two fillups.

Ghozt

^ yeah what he said, the live meter is cool to watch but not very accurate. i average 15-19 mpg in the city with traffic, and 20-31 on the highway (31 being a pure highway trip)

my engine also idles around 600 rpms after warming up, starts out idling around 1200 when started cold. since you're at 60k miles, thats the recommended time to do the CVT transmission fluid drain/refill which can be very helpful to the car (increase power, mileage, throttle response). if that isnt on the cars service record that'd be a good place to start in terms of tune-up (as well as some nice synthetic like Mobil1"

and yea hmu if u have any questions, ill be glad to help

Celidor

Maybe I am considering the "live" fuel meter to be too accurate. But it certainly seems to be fairly accurate, and If I drive "with the flow" around Toronto downtown traffic it will be saying 10.5 to 12 (22-18mpg) and worse if I'm heavy on the gas. The meter has also been helpful in getting used to the car in response with the gas pedal. I have been using it to help get a feel for how to drive the car with max fuel economy in mind. I like to learn how to get the best fuel economy in a specific car before I really let it loose and in turn forget about fuel consumption for awhile.

I understand completely about the cruise control and it's limitations. I should have clarified better. I did not drive only with the cruise control but on some of my earlier driving trips I tried using the cruise control on flat runs at 100km/h. Uphill I cancelled cruise and let it lose a bit of speed. Downhill I touched the gas pedal to let gravity do it's work and stopped the cruise control from holding 100. I was trying to see how good my highway fuel economy could be when I was doing this. (Someone should design a cruise control with a max, min, and desired speed settings so it just keeps the car within a certain speed range)

And about the fact that I recorded 30 mpg in the city. This is at night. With practically no traffic, outside of the "city", on 60-80km/h roads. And I will go 10km over posted if it seems safe to do so. My car got over 30mpg without a whole lot of effort on my part, I even had the sunroof open and smoked a bit with my girlfriend beside me. On country roads going around 65 to 88 this car just purrs quietly pushing you along and getting close to 40mpg according to the computer. 40 at least as long as you don't have to push the brakes. lol. But anyway please take in mind that fuel economy of 30mpg was recorded by someone driving with a focus towards using as little fuel as possible. Although I must say that I wasn't just loafing around going slow, this car has some power, and I don't find going overly slow actually helps fuel economy anyway, I even had the sunroof open for part of it.

So bottom line is that 32mpg is what some others have recorded on the highway so I don't see how me getting close to that in the city is so impossible. In a few months when I have more solid data I would be happy to share my fuel numbers. I can guarantee I can get 26-29 city driving without any special techniques or forethought on my part. Just driving the car around only avoiding gunning it but otherwise driving in an enjoyable, somewhat speedy manner. And I was frankly surprised reading other people's mpg ratings and not seeing anyone's up near the 30's except on the highway. When I get 15 recorded fill-ups I will post my data, until then please just take it for what is is. I'd like to focus on the problem I have when going highway speeds.


So anyway! Regardless of what the fuel meter is telling me the car feels like it is having to work harder on the highway than I think it should, at first when I got the car and went on the highway it was revving a bit high but after a little bit of driving it started to run better and then when I cruised at 100kph (62mph) the engine rpms stayed purring at 2000 or just under and it came back with 7.7l/100 (30.5mpg) which is exactly what I have read many owners getting on the highway. But it has never ran that well since that drive. Sometimes returning as bad as 10l/100 and revving at 2400k rpm in the same flat highway conditions. Also sometimes the car acceleration is responsive and other times it is laggy. The car is not in bad shape but it definitely needs some TLC. I still have rust I need to deal with, but I'm just trying to focus on getting the power-train running smoothly before I deal with the body.

I am not swimming in cash or I'd have already sent it in for a full tune-up by someone who really knows their Maximas, it would be nice to take the car up north in a few weeks but I want to get the car running better before I do. I would really like if someone could chime in with what I could do that would most likely fix the problems I'm having with the car.

-The idle gets a bit rough if it sits for more than a minute.
-The car and steering wheel has started vibrating more than usual at some rpms. (very recent)
-The acceleration and response of the car/gas pedal is inconsistent.
-The car's mileage and rpms at speeds over 90km/h is inconsistent on flat ground.


My first official "gas station" fuel economy number that I recorded was 9.45l/100km (24.9mpg) about 65/35 city/highway I found that to be slightly a disappointing number but not surprising, it was about a 745km trip.

Second was 8.8l/100km. (26.7) 75/25 city highway and I forget the kms.

The cars computer, although I reset it a few times during the tanks, reflected these numbers. Maybe I should not reset it for a full tank and see how close the numbers are but I trust it to be fairly accurate, and it does seem in tune with the sound of the engine once you are cruising along.

As you can see these fuel numbers even reflect the fact that the car is getting worse fuel economy on the highway than it is in the city. This only backs up how the car already feels when I'm behind the wheel. It's messed up, I am getting better fuel economy if I drive on the back roads! Than cruising down the freeway.

For all I know changing to summer or all-season from these winter tires would make it a lot better. But I really don't know if that would fix it completely.

I want to change the tranny fluid, air filter, spark plugs, and look into getting the throttle body cleaned but it's pretty new stuff to me and though I'm sure the car would appreciate all of those things, It'd be nice to know what is most likely going to fix the problems.






P.S. I am used to getting better than recorded MPGs. My last car was a 1998 Honda Accord Sedan, 3.0L V6, 4 Speed Auto 200hp/196ft*lb. And once I got used to the car I regularily got 8.4-8.9L/100km (28-26.5mpg) whether highway or city it was never over 9l/100km (under 26mpg). Even though it was rated at 18mpg or 13L/100km in the city. Those EPA ratings are just a guideline if you drive the car right you can easily beat them and still get places just as fast. And by right I don't mean boring and slow, I have no training in hypermiling nor have I read much into peoples techniques, and passengers would attest that I am not driving around like grandma. I enjoy hearing the tires squeal from a dead stop. I am learning I have to be more careful with the maxima though, as it can suck the gas down very fast when you push it compared to my 3L Accord. I know this engine is 0.5L larger, 90 hp and 70 ft*lb more powerful and the car is 1000lbs heavier than the old Accord which was designed with economy as a priority, but with modern advances in engines and fuel injectors and the CVT transmission why is it impossible for me to get over 30mpg city? Driving through the city at average speeds of 50-90km/h I truly believe this car can use less than 8L of gas per 100km with the A/C working lightly, a light foot once you reach cruising speed, and using more roads with less stoplights when possible it should be easily achievable. I'm just disappointed with how the Maxima is performing on the highway. In my crappy 4-speed I could zoom down at 120-130km/h and still get under 8.6L/100km (27.4mpg). If I go those speeds with the Maxima on a nice flat run it seems to get anywhere from 8l/100 (great) to 13l/100 (terrible).

Sorry if I went off rambling, I'm tired. And also annoyed that there is such strong doubt about what I am saying. I just want help with what could cause these problems not a debate on whether the fuel meter is accurate or if 30mpg city is possible without extreme techniques.

Celidor

Also, I believe from my experience that the cruise control will allow the car to go a little over the set speed. About 2-3km over before it starts engine braking. So it would seem to be fine to be left alone on slight declines as well as flat runs. Slight inclines though, I am not so sure, it seems to be very touchy if the car drops even a km below the set cruise speed.

lightonthehill

While I'm thinking about what could be causing your situation, I want to make sure we are both talking about the same meaning of the term 'city driving.' As used to define government fuel efficiency standards, the term has absolutely nothing to do with whether we are in, near, or far removed from a city.

The term 'city driving' as defined by government standards in reference to fuel efficiency refers to something like driving conditions where we in a 'stop-and-go' situation, moving at a fairly slow speed, usually fluctuating between being stopped and 30 MPH, with overall average speed around 10 to 15 MPH.

When driving in a situation where we are able to go stretches as far as a quarter mile without having to stop at a traffic light or stop sign, we are not within the general window covered by 'city driving' as defined by government 'city driving' fuel efficiency standards.

Under the true 'city driving' standards, I must drive very carefully to get 17 to 19 MPG. As I get just outside the true 'city driving' situation, my MPG edges up to around 20 to 22. Once I am able to reach speeds around 45 MPH and fewer traffic lights and stop signs, I am in 'suburban' driving conditions, and my MPG moves into the 22 to 25 range.

Cruise control situations vary greatly with the terrain. For instance, in driving on I-85 from Atlanta to South Carolina, most of the stretch is simply one hill after another. The down slopes can be almost a mile long and not always gentle, and the loss of momentum due to engine braking by cruise control significant, fuel-wise. The upslopes can be equally long, with the rpms actually moving from around 1850 to almost 3000 if the driver does not intervene. I love cruise control, but never bother to try using it on anything but fairly level roads with light traffic.

After reading all your posts concerning your current situation, it is very clear that something is not right with your car. The worrisome thing is that your car is not consistent. You never know how it might do from one trip to the next.

I always have all scheduled maintenance done on time by my dealer, so have never experienced the things you are enduring. I think you are headed in the right direction by replacing the air filter, spark plugs, tranny fluid, and getting the throttle body cleaned. But I'm not sure those will fix the problem, as those are not the types of things that would normally cause such inconsistent performance. Maybe throttle body gunk might.

There is a lot of EPA pollution control stuff on these cars, and I think there are pollution control filters of some type that should be replaced at intervals. But surely someone here on the ORG has experienced something like the inconsistent performance you speak of, and will have some ideas. I will try to think of possibilities.

Celidor

Thanks for your input "lightonthehill". The 30mpg trip was actually more like 70% suburban, 25% city, 5% freeway almost all at night. I've always thought having only city and highway percentages listed was not accurate enough in describing the driving scenario. I tried to explain in my earlier post that it was mostly 60-80km roads outside of the "city" that got me 30mpg, but suburban seems like a simpler, easier to understand description. The average speed if I remember correctly, according to the computer was 68kph (42mph).

In true city driving I've been getting 9-10L/100km (26-24MPG) depending on how many red lights I get and the traffic. With an average speed of about 20mph. Maybe it is just the way I'm driving. When I was driving downtown Toronto in bad traffic and stoplights at every intersection it starts to creep up higher into the 10s (22-23mpg) or at least that is what the computer is showing, as I don't usually drive in the downtown core very often, it's all I have to go on.

I haven't driven a lot on the highway except for short trips, so I've mostly been driving city, but I have never gotten over 9.8L/100km (less than 24mpg) when calculating at a fill-up, it would seem that is exceptional numbers to be getting. And I'm pretty happy about how it's been performing although I still think it could do better if it was more responsive.

But yes, it is concerning and frustrating to me that the car isn't performing consistently. I can understand if the engine is still warming up that it might be working a littler harder. But this is not the case as it doesn't seem to matter how long it's been running. Even when driving at slower speeds the car will sometimes start revving more than I think it should but when this happens and doesn't go back to normal quick enough than I'll accelerate the car higher than the speed I want to go let it drop back down to the speed I want to be going and it usually will be fine for awhile. And I'm not talking about the fact that I have more momentum. The rpms will stay down lower even after I've come to a stop and continued on. I don't know why revving it up higher helps. Could this perhaps point even moreso at a mugged up throttle body?

I was really hoping the transmission fluid might fix the problem but I still have yet to change it. 100km/h on a level road should be getting me 7.7L/100 and revving at 2000rpm but most of the time is getting 10l/100 and revving at 2400. Also at 40km/h the car will often have trouble holding that speed and keeping steady rpms. It either wants to accelerate or engine brake. This kind of thing has led me to believe and hope that maybe if I let the car completely run out of electrical power and have it reset that it could start to learn my driving habits better.

I wish I could have bought the car new, or with fewer miles on the odometer. But I got 96,000km and I have no idea how well it was taken care of. And the previous owner was leasing. I plan to do a lot of work to hopefully get her running like new. Then remove all the rust, rustproof it. And have this car for at least 10 more years.

If anyone else is having similar problems or knows what to look at first for the problem it would be greatly appreciated.




And about my MPG (If anyone wishes to know). My normal driving habits in the Maxima (on 50-80kph roads) are to accelerate the car at 1800-2100rpm from a dead stop depending on the incline. Than when I get really close (like 3kph, 2mph away) from my desired speed, I let the rpms drop down, but not below 1500rpm. Than I let the car accelerate a little more, just past the speed I want to go and proceed to hold the rpms at a point that is actually letting the cars speed decrease very slightly. At this point I would look down at the live fuel meter and it should be at about 4-6 or around halfway between 0 and 10 (for U.S I'm assuming it should be at about 40-60mpg) and I let the car's speed slowly drop into the desired cruising speed and hold the pedal at whatever point is keeping the speed I want.

The fuel meter should read about 6l/100 or 40mpg, at least it does for me. And the rpms should be at about 800. If you are going 55-80kph (35-50mph) on a flat road.

This may seem complicated but it isn't really and once you get used to it, it becomes habit and takes very little thought. This of course doesn't work quite the same in gridlock or if there is a stop sign ahead.

Serpent

Could get interesting if lightonthehill has a competitor for "longest poster in the forums" now with Celidor getting going. Lol

Jk guys, interesting read here. The only thing I want to add is that the live meter is good for being able to visualize fuel consumption to learn a (perhaps) more efficient method of acceleration. However using the MPG calculator, even comparing it AGAINST ITSELF, is not worth your time. Terribly inaccurate and inconsistent, unfortunately.

Please continue to post your findings. I'm particularly interested to see the benefit from changing the transmission fluid. There have been several threads about whether it should be changed at the regular maintenance 60,000 miles, or the aggressive schedule of 30,000 miles. So I'm excited to get a detailed post about the noticeable differences after changing the fluid.

Carry on, gentlemen.

silberma

Celidor, Your message says that you intend to remove the rust and rust proof your car. I find this incredible because all recent make cars are two sided galvanized and Nissan in addition applies a light coat of the external sheet metal that looks like a sound deadner. Please explain.

Celidor

I screwed up a bit there so I wrote it out better:


And about my MPG (If anyone wishes to know). My normal driving habits in the Maxima, most specifically on any 60-70km(35-45mph) roads are to accelerate the car at 1800-2100rpm from a dead stop depending on the incline. Than when I get really close (like 3kph, 2mph away) from my desired speed, I let the rpms drop down, but not below 1500rpm. Than I let the car accelerate a little more, just past the speed I want to go and proceed to hold the rpms at a point that is actually letting the cars speed decrease very slightly. At this point I would look down at the live fuel meter and it should be at about 4-7 or around halfway between 0 and 10 (for U.S I'm assuming it should be at about 47mpg) and I let the car's speed slowly drop into the desired cruising speed and hold the pedal at whatever point is keeping the speed I want.

The fuel meter should read at best, about 6l/100 or 40mpg, at least it does for me. And the rpms should be at about 1200-1400. If you are going around 55-80kph (35-50mph) on a flat road.

This isn't the greatest explanation, but it keeps me under 9L/100 (city driving) when I follow it. This of course doesn't work quite the same in gridlock or if there is a stop sign ahead. You have to try to keep your momentum and not get stuck in slow accelerations.

IMO
The Maxima's engine seems to gain better fuel economy when it's pushed up to cruising speed quicker (compared to an economy sedan). If you slowly accelerate up to speed, following the flow, your MPG will suffer. But if you are going to have to stop in a moment it is better to just give the car a smaller burst of speed and coast to the stop. Avoid chugging along at speeds under 40km (25mph) especially. At those speeds I've found it's better to drive with a combo of small bursts of gas and coasting.


Note: Where I live 40km roads are often treated as 50kms depending on the day. And 50km roads are easily 65kms, etc, and you will be getting passed at that speed. Some people take it too far and drive unsafely IMO, but anyway. It may be part of why I'm getting MPG numbers that seem too high to some of you. If you can avoid the reds you can get cruising through the city at fair pace and be burning 6 liters per 100km or better at times. 40+ MPG. Sure, you'll run into a red or stop sign sooner or later. But the more of those 40mpg moments you are getting the better off your average MPG is going to be. But even in heavier traffic, and a lot of stop and go, it is still quite possible to stay well over 22 mpg. And 20mpg (11.7L/100km) I would think wouldn't even need an overly light foot to achieve from my experience.

Ghozt

I agree with your assessment that slow acceleration does not save gas. I also find it better to get "up to speed" quickly and then let the car coast. the CVT is definitely its own animal

lightonthehill

I agree about getting up to speed more quickly, doing so without revving the RPMs very high, and then cruising with low RPMs, using short bursts of power when needed.

I now see where you are getting your high fuel efficiency. We just have to keep in mind that this system of driving and reducing the number of stop signs and red lights does not qualify as true 'city driving' by the standards set for measuring city driving fuel efficiency.

I do admire your efforts in finding ways to improve your fuel efficiency. If everyone drove with fuel efficiency in mind, there would be a lot less fuel consumed in North America.

silberma

I admire your effort to reduce gas consumption, however, in my opinion this defeats the purpose of buying the Maxima which is really a sport sedan and should be driven that way. If I wanted high MPG I would have bought a 2013 Altima 4 cylinder that gets 38 MPG

AlDente67

My car is only 7 months old with 3k on the ODo, and I was surprised to get an average of only 24.5 MPG at best on a 200 mile trip that was 97% pure highway at 70mph or so. Thought it would come in a bit better. In town, I tend to enjoy the launches, so this was my first true test of the sedate cruising.

The OP's car is doing much better.

Ghozt

Yup. Nailed it. First couple months I had my Max I was really concerned about the mileage and watching it like a hawk, coasting everywhere, etc. Then after awhile I was like wtf am I doing this for, I got a 3.5 liter V6 because I want to drive it like a sports car not like driving miss daisy.

Celidor

First, I haven't done anything to the car in the past week as I am still trying to acquire some of the correct tools. But during this week I took it out driving a lot and it started to run just a little bit better so I decided I'd take it out and drive it a bit harder and for longer periods at "higher" speed. That I could safely get away with. And the "power-train performance" ,for lack of better words, started to improve a bit. After the car was more thoroughly "put through the paces" it was running nicer. At lower speeds as well.

On average, the rpm's are more steady when climbing, and are holding more steady when you are driving at a steady speed and incline. Where before they would raise and lower for seemingly no reason. it is still not perfect and will act up sometimes. It also runs a lot more steady when idling, at least after a long warm-up. The fact that it has improved after being driven harder is making me wonder what could partially fix itself by having me drive the car harder and faster?

Either way I haven't even done the tune up and my problems have improved to some degree. Even the fuel numbers from the computer are coming back better. Although the car is still not running as consistent as it should be! It is better. And on a highway trip a couple of nights ago I got 6.7l/100 at the halfway point but after the way back it turned into 8.0l/100 average. Which isn't bad at all it would seem and I would not be unhappy with that if it could get that consistently. But on the way back I was having to push the pedal harder and push the rpms higher just to keep the speed limit of 100km at times. And one or two of these occasions was on a downhill slope! So I don't see how you can rationalize that as being normal. That is extremely inconsistent.

A long, about 8-10 degree downhill slope at 102km(63mi) and I had to push the pedal further than usual to keep that speed. And my fuel meter was just over the 10, I'd say at 11l/100km(21mpg) when it should definitely be below 8 (above 29) when cruising at 100km, with no wind on the freeway.


I've been thinking about whether it's the transmission and computer trying to learn how to drive differently than the previous owner who may have rarely ever driven it fast but I don't know. Seeing as it seemed like it was used like a family car, there is an indent that is fading away from a child seat on the back as well as other evidence left behind suggesting a woman may have actually been the main driver with husband as secondary with 2 young kids. Does anyone think that could mean something about the car's current performance.

Is it possible after 96,00km for a car to still not be completely broken in?! Do I need to take this thing to a race track once I give it a tune-up to get this baby running properly? I'd love an excuse lol.

__________________________________________________ __________________________________________________ _______________________________________

Second thing, In regards to the posts about driving the car in a way which was unintended for such a sporty car, or driving miss daisy lol. That is pretty far from the truth. But I can see why you might make that assumption.

Ok, so firstly I don't drive around like I'm driving with miss daisy in fact since getting the Maxima from my 98 Accord sedan I drive a little faster and turn a lot sharper even during the most basic driving to grocery store kind of stuff because Maxi likes it that way. This car doesn't need to guzzle gas to go fast. But boy is she capable of guzzling gas even at lower speeds.

With the way I drive the car around I'm getting 9.5L/100km (24.8MPG) average. And that is with the problems I am having on the highway. I don't drive the same way all of the time. Who among us 7th gen Max owners does?? I'd wager very few. Sometimes I'm just cruising around getting 8l/100(29mpg), other times I am racing around getting 10-13(18-23mpg). Or even 14-15(15-17mpg) if I'm really zooming through the city.
If I am driving doing errands driving through the city I try to not suck up a bunch of gas but I actually find myself going faster than most people around me. Including from a dead stop at a stop light. Driving is a joy to me, part of the reason I don't want to burn too much gas for no good reason, so I can drive for longer and more often. If I wanted to, I think I could probably get about 8.5L/100 in mostly all city with some suburban driving but... that would mean never letting loose and pushing the car hard.

Please don't assume I drive slowly and that it is the only way to achieve 25+ mpg because it is not true. Even the method I explained in an earlier post accelerating at 2,000 rpm is not particularly slow and is how I would describe normal somewhat serene acceleration for the Maxima. That acceleration is well suited to city driving. And has been in fact too much acceleration at times when driving downtown with traffic and people popping out between cars.

Everyone will drive their own way and however they please. But there can be huge differences in fuel savings by changing how you drive slightly. This car in particular seems to be able to burn a lot more gas for little improvement in speed or acceleration with just a small amount of extra depression on the gas pedal. I have no other Maxima to compare it to, but I believe this is a quirk of how the gas pedal works in relation to the CVT transmission (the pedal telling the tranny what you want). The pedal is so touchy.

This is how it works for me in the city. You can be driving, droning along at 10L/100(23mpg) through the city, with just this tiny amount of acceleration that can be barely noticable on the speedo. And letting off of the gas a tad, the engine will quiet, the meter will drop to 7 (33mpg) and you can hold that speed/rpm/fuel rating, possibly all the way to your next stop. All you lost was a tiny amount of speed which you could easily have made up for by getting up to a faster cruising speed in the initial take-off. None of this involves driving slowly and you only need to do it when you are just intending to drive along at a steady speed anyway. If you don't have another car directly in front of you it is extremely simple. Things change below 40km and start to change somewhere above 80km for my car.

Anyone else experiencing the gas pedal being touchy and able to suck up gas for little power increase? I find if you are trying to get good fuel economy in the city it is good to be watching the rpms closely during accelerating and making sure that you are pushing the pedal down enough to get a significant increase in rpms, in other words accelerating more if the rpms aren't high enough. In other words faster! If people are trying to get good fuel economy and driving this car just the same as they would with a less powerful engine, and traditional automatic they are probably going to be frustrated. No predefined gears takes some getting used to in being in tune with the drive.


P.S. And about the rust I will post what ever I do about it when I come to that point. Sometimes metal needs to be sanded and rustproofing applied.

DansMax09

I'm getting 23.7 mpg and 32.0 mph. That's with a 30 minute drive to work on a hilly Interstate 5 days a week with a lead foot, atleast from a stop. I alternate from mid grade to premium gas every other fill up. That's not bad at all for the power this sexy beast has to offer. Lol

newsat65

I am averaging 18 city and 25 hwy

Celidor

It's funny, the only reason I was mentioning the fuel economy in the first place was as an example, a symptom, of the problem I'm having with the car. How the engine is working smoothly at one time and than has to work extra hard at another time in the same driving conditions.

Celidor

That sounds about right. At 32mph average with quick take-offs I'd expect to get at least 0.5 mpg better, but that's not taking into account a lot of hills so, not too shabby. Lead foot on the gas is better than a foot always going to the brakes. My car is running pretty good but once I get onto the highway and up to faster speeds that's when the problems really become noticeable. Although it isn't constant as the car will seem to drive as it should at times.

My friend told me that changing grades of gasoline constantly is a bad idea. But I really don't know if that is true or not. We're talking a difference of 2 octane. You'd think it wouldn't be a big deal. But a lot of people on the forums say 87 is too powerful to use at all. I wish I knew the truth.

For now I'm only using 91. Won't try 89 or adding 87 into the mix until I've done some work and fixed the problems.

lightonthehill

I agree that it is better to select a grade of gasoline and stick with it. I don't know about the 7th gen, but the 6th gen manual discouraged switching grades regularly (and mixing grades is the same as switching grades).

89 octane (midgrade) works wonderfully well in the 7th gen, but NEVER use regular (87 octane) in a 7th gen Maxima. Some folks think 87 works fine. I personally think it may risk damage to the engine, especially if the engine is unable to run smoothly with regular in the tank (several posters here had this happen). I know for sure the 7th gen Maxima does not run as efficiently on 87 octane, as the fuel system has to adjust too far from the range of fuel it is expecting.

The 7th gen Maxima absolutely does factor in the driving style of the driver, and it may be that some of that adjustment carried over from the previous owner.

newsat65

How the hell are you getting 32mpg average!!! Now I think there is something wrong with my car!! I am averaging 22mpg! Does anyone else on this forum get 32mpg........

Serpent

I think you're mixing up 32 mph with 32 mpg

silberma

On a 12 mile commute to work I am getting 24.5 mpg at 39 mph. I started with 91 octane and after a few weeks switched to 89 octane with no noticable difference. I may next try 87 octane.

The problem with listening to friends is that most are not technical experts and dispense their opinions much too freely. As an engineer I can tell you that modern engines have anti knock sensors to adjust the engine ignition timing based on the octane ratings and detection of engine knock, so switching fuels does not affect the engine reliability. In fact my friend has an infinity G35 with the same engine and has been running 87 octane in it for 6 years without issues.

newsat65

Others have talked about fuel economy in other threads but I couldn't find any answer to my issue. I recently purchased an 09 SV with 96k kilometers.. That's around 60k miles.

I have been getting excellent city fuel economy about 8-9l/100km (29-26mpg) and when driving at night with less traffic and more 60-80km roads I can get about 7.4l/100km (32mpg).
No he said 32MPG

Celidor

Yes, the Maxima is capable of 32mpg down suburban roads. Cruising 60-90km/h. Heck with no stop signs going 50mph(80kph) the car can be getting 40mpg. But as soon as you have to stop you are going to need to burn more fuel to get back up to cruising speed. The more stopping, the more fuel you are going to need to burn because of that. Which is why people say braking gives you bad fuel mileage.
(Which in a way is ludicrous because braking has no direct connection to burning fuel and in fact using the brakes to slow you down earlier when coming to a red light to keep forward momentum and not have to completely stop will improve mpg..)

You should read carefully...
32mpg is not what you should expect to get driving in stop and go traffic. 26-29 mpg was the best I was getting when driving through the city with a lot of focus on fuel economy... Don't expect those kinds of numbers when driving through heavy traffic with a heavy foot.
When you are driving on a lot of 60-80km (35-50mph) roads you can get mpg's in the 30's depending how you drive. Which unfortunately is Not as simple as: drive slower and you'll get better mpg.

Celidor

There could be something slightly wrong with your car as in, maybe it could be running better and smoother. But more likely it is just the way you are driving. If you are not particularly aware of your car's revs and fuel consumption as you are driving than you shouldn't be worried about 22mpg average especially if you are driving in heavy traffic a lot.
It's hard to get good mileage with a lot of stop and go.

lightonthehill

True. I average around 17 MPG in downtown Atlanta. Thank goodness I seldom have to go there anymore. I'm getting 22 to 25 MPG in suburban driving, and I am not as careful as Celidor.

premiummax

How in the world are you getting 31mpg? Mine only gets 22mpg highway and that was the max

240tomax

Part of the confusion could be how Celidor calculates miles per Gallon. Canada uses the imperial gallon which is 4.54 litres. The USA uses the US gallon which is 3.78 litres. The US gallon is almost 20% smaller, so 31 MPG in Canada equates to about 25 MPG in the USA.