Amazing HWY MPG
04-11-2004, 06:28 PM
#1
Senior Member
Thread Starter
Join Date: Mar 2004
Posts: 142
Amazing HWY MPG
Ok, I live in Boston, and go to college in NH. I was home for the weekend and left to go back to school today. I decided to test my MPG, so i filled up before i git on the highway and filled up when i got off in NH. On the 99% highway trip I got 30.7 MPG. I have never gotten this before, so I was pretty amazed. (I have a 01 SE Auto). I was in no rush so I had it on cruise control at about 70. When I had to accerated, i only brought the tach to about 2500 at most. I usually go about 80-85 and get about 25-28 mpg on highway. Have any of you with a 00-01auto gotten this good MPG? My car is Stock for now. I am looking to get a cattman Y Pipe and berk intake this summer? Will this do anything to my MPG? How much will these two combined decrease my 0-60 and 1/4mile? Thanks for your input.
04-11-2004, 07:39 PM
#4
I've been able to get 32 mpg per the trip computer on my 02 Auto. Drove to Cleveland and back (300 miles) on half a tank. I find that i get the best gas mileage with the cruise set at 68. Only mod to date is Berk Intake with K&N.
04-12-2004, 03:58 AM
#11
Senior Member
Join Date: Dec 2003
Posts: 277
I get pretty high MPG on the highway too, usually 29 - 31 if I keep it under 70....I noticed full synthetic makes a huge difference in MPG. I had a SPEC V 6 months ago and used to get about 26mpg on the highway driving to Michigan. First time I put in Full Synthetic it went to like 32 - 33, it was crazy.
04-12-2004, 05:08 AM
#12
ever since I installed the Berk intake and midpipe, my car growils and drinks gas w/ a straw. I fill her up every 3 days (2 days sometimes when I drive around to show off my ride)...that is about $30!!
Should I get a 3 banger Geo metro??
Should I get a 3 banger Geo metro??
04-12-2004, 06:47 AM
#13
Supporting Maxima.org Member
Join Date: May 2003
Posts: 908
My mpg went up with the Injen. I was getting 20 with city driving and now get 23 after the install. The best mpg I ever got was going to Boston from Raleigh, NC. We started the trip at 9 pm and drove all night long. I got 31mpg calculated and 34 on the computer. If you reset your computer right before you get to a large decline, you can get the computer to read extremely high numbers. I had mine peak at 74 one time.
04-12-2004, 08:26 AM
#15
Originally Posted by SEmy2K2go
I've been able to get 32 mpg per the trip computer on my 02 Auto. Drove to Cleveland and back (300 miles) on half a tank. I find that i get the best gas mileage with the cruise set at 68. Only mod to date is Berk Intake with K&N.
04-12-2004, 09:56 AM
#18
Senior Member
Join Date: Jun 2003
Location: NM
Posts: 2,145
I thought something not right, getting a high mpg. I think you either calucalated incorrectly since the 00-01' does not have a MPG meter on it. Check your math. I know my average is about 22mpg in city and 26 hwy.
04-12-2004, 11:25 AM
#19
Donating Maxima.org Member
Join Date: Nov 2003
Posts: 191
Originally Posted by FanaticMadMax
I thought something not right, getting a high mpg. I think you either calucalated incorrectly since the 00-01' does not have a MPG meter on it. Check your math. I know my average is about 22mpg in city and 26 hwy.
04-12-2004, 03:59 PM
#21
Senior Member
Join Date: Feb 2004
Posts: 177
Don't believe the cars computer on what your MPG is, they are known to be way off. I'm trying to get folks to fill out a survey on actual mileage, versus what the computer calculates. The survey is here -->
http://forums.maxima.org/showthread.php?t=300922
As a note, I've actually gotten 31.15 MPG once on my 6 spd '02, but to do it I had to drive like a Grandma and never once got above 2500 rpm, but at least I got to see what it could do. The indicated MPG from the trip computer on that tank was 37.2 BTW.
If you've got any data to report, please post it to that thread so I can start figuring out exactly how bad on average the computer is.
Thanks.
http://forums.maxima.org/showthread.php?t=300922
As a note, I've actually gotten 31.15 MPG once on my 6 spd '02, but to do it I had to drive like a Grandma and never once got above 2500 rpm, but at least I got to see what it could do. The indicated MPG from the trip computer on that tank was 37.2 BTW.
If you've got any data to report, please post it to that thread so I can start figuring out exactly how bad on average the computer is.
Thanks.
04-12-2004, 04:39 PM
#22
Senior Member
Join Date: Jul 2002
Posts: 2,836
Originally Posted by 3Pedals_6Speeds
Don't believe the cars computer on what your MPG is, they are known to be way off. I'm trying to get folks to fill out a survey on actual mileage, versus what the computer calculates. The survey is here -->
http://forums.maxima.org/showthread.php?t=300922
As a note, I've actually gotten 31.15 MPG once on my 6 spd '02, but to do it I had to drive like a Grandma and never once got above 2500 rpm, but at least I got to see what it could do. The indicated MPG from the trip computer on that tank was 37.2 BTW.
If you've got any data to report, please post it to that thread so I can start figuring out exactly how bad on average the computer is.
Thanks.
http://forums.maxima.org/showthread.php?t=300922
As a note, I've actually gotten 31.15 MPG once on my 6 spd '02, but to do it I had to drive like a Grandma and never once got above 2500 rpm, but at least I got to see what it could do. The indicated MPG from the trip computer on that tank was 37.2 BTW.
If you've got any data to report, please post it to that thread so I can start figuring out exactly how bad on average the computer is.
Thanks.
04-12-2004, 04:44 PM
#23
Member
Join Date: Aug 2003
Posts: 58
The ONLY way to accurately calculate mileage is distance (on the odometer) divided by gas consumed (fill up to fill up), IDEALLY using the same pump / location for each fill up (to minimize effects of pump-to-pump variability, car not being level, etc.). Over time, the variability fill-up to fill-up will cancel out.
My '00 auto Maxima is averaging 21.9 MPG in 90+% city driving; not much different than my previous 4 cylinder Camry around town. I did not detect any increase in MPG when converting to synthetic (frictional losses in the engine are very minor relative to aerodynamic drag, tire drag, and driving technique).
The computer is trying to do the same thing for MPG calculations, but as 3Pedals mentioned, it will become more inaccurate as the actual MPG increases, as the flowrate, used to estimate fuel consumption, decreases relative to the distance travelled (the distance travelled is pretty accurate).
Also, you can't accurately average MPG by using a simple mean...you have to use the same formula above using the SUM of the distances and fuel used (this will give a different number...try it using real data). Just arithmetic mean is wrong, as distance traveled between tankfuls will vary (as a function of the MPG!).
My '00 auto Maxima is averaging 21.9 MPG in 90+% city driving; not much different than my previous 4 cylinder Camry around town. I did not detect any increase in MPG when converting to synthetic (frictional losses in the engine are very minor relative to aerodynamic drag, tire drag, and driving technique).
The computer is trying to do the same thing for MPG calculations, but as 3Pedals mentioned, it will become more inaccurate as the actual MPG increases, as the flowrate, used to estimate fuel consumption, decreases relative to the distance travelled (the distance travelled is pretty accurate).
Also, you can't accurately average MPG by using a simple mean...you have to use the same formula above using the SUM of the distances and fuel used (this will give a different number...try it using real data). Just arithmetic mean is wrong, as distance traveled between tankfuls will vary (as a function of the MPG!).
04-12-2004, 04:48 PM
#24
Senior Member
Join Date: Dec 2001
Posts: 554
Originally Posted by Quicksilver
I assume you're talking about your CRX? If not, then do you have some kind of electrical system set up to kill 2 cylinders at highway speeds?
although, that'd be an interesting idea to kill two of the cylinders on a cruise. if it was a flat terrain, you could run on 4 and still have no problems.
except maybe head warpage due to the two cylinders being a different temp.
i think 40mpg is doable on a freeway in a Maxima if you run some conservative fuel maps (assuming you have something to adjust fuel mixture and various RPMs).
04-13-2004, 06:56 AM
#26
Originally Posted by Driven EF9
yeah, it was the CRX (switching the vtec at a higher RPM and adjusting fuel maps for freeway).
although, that'd be an interesting idea to kill two of the cylinders on a cruise. if it was a flat terrain, you could run on 4 and still have no problems.
except maybe head warpage due to the two cylinders being a different temp.
i think 40mpg is doable on a freeway in a Maxima if you run some conservative fuel maps (assuming you have something to adjust fuel mixture and various RPMs).
although, that'd be an interesting idea to kill two of the cylinders on a cruise. if it was a flat terrain, you could run on 4 and still have no problems.
except maybe head warpage due to the two cylinders being a different temp.
i think 40mpg is doable on a freeway in a Maxima if you run some conservative fuel maps (assuming you have something to adjust fuel mixture and various RPMs).
You could easily alleviate the head warpage by alternating which two cylinders are shut off at a given time...
04-13-2004, 03:02 PM
#27
Member
Join Date: Aug 2003
Posts: 58
FusionAcid:
Follow instructions provided above to accurately determing gas mileage. Distance between tank fillings / gas used (full-to-full -- wait 'til pump shuts off) is most accurate way to determine MPG. Increase accuracy by summing the distances traveled and dividing by the sum of the amount of fuel purchased (used).
Follow instructions provided above to accurately determing gas mileage. Distance between tank fillings / gas used (full-to-full -- wait 'til pump shuts off) is most accurate way to determine MPG. Increase accuracy by summing the distances traveled and dividing by the sum of the amount of fuel purchased (used).
04-13-2004, 03:17 PM
#28
Member
Join Date: Aug 2003
Posts: 58
"Killing" cylinders will only help mileage SLIGHTLY, and will make for one rough-running engine. Cadillac tried this years ago on it's infamous 8-6-4 cylinder engine. The idea was to save fuel by shutting off cylinders under low / no load condition (i.e., highway cruising). Never heard about it? That's 'cause it didn't work very well, and most folks quickly disabled it. I can't remember, but it may have used valve control as well to reduce pumping / frictional losses (check the internet).
Just shutting off fuel won't help much, if at all, as frictional and pressure losses become VERY high since the pistons (not contributing to power) still need to move air, compress it, have rotational mass, etc...not good. Simply creating drag, not power. Ever drive a 6 cylinder car with a fouled plug? Not pretty.
If you want significantly better gas mileage, sell the Maxima and get a CRX, Civic, or a Volkswagen TDI (albeit a diesel). If MPG was easily increased without penalizing performance, don't you think the automotive companies would be using the technology (they, and we, are penalized financially for not meeting CAFE requirements)? Most are embracing hybrid technology now, as diesels will face tougher emission rules soon in the U.S...emission standards are lighter in Europe for diesels, where nearly 30% of passenger cars use diesel engines.
Just shutting off fuel won't help much, if at all, as frictional and pressure losses become VERY high since the pistons (not contributing to power) still need to move air, compress it, have rotational mass, etc...not good. Simply creating drag, not power. Ever drive a 6 cylinder car with a fouled plug? Not pretty.
If you want significantly better gas mileage, sell the Maxima and get a CRX, Civic, or a Volkswagen TDI (albeit a diesel). If MPG was easily increased without penalizing performance, don't you think the automotive companies would be using the technology (they, and we, are penalized financially for not meeting CAFE requirements)? Most are embracing hybrid technology now, as diesels will face tougher emission rules soon in the U.S...emission standards are lighter in Europe for diesels, where nearly 30% of passenger cars use diesel engines.
04-13-2004, 03:37 PM
#29
Senior Member
Join Date: Jul 2002
Posts: 2,836
Originally Posted by rbneron
"Killing" cylinders will only help mileage SLIGHTLY, and will make for one rough-running engine. Cadillac tried this years ago on it's infamous 8-6-4 cylinder engine. The idea was to save fuel by shutting off cylinders under low / no load condition (i.e., highway cruising). Never heard about it? That's 'cause it didn't work very well, and most folks quickly disabled it. I can't remember, but it may have used valve control as well to reduce pumping / frictional losses (check the internet).
Just shutting off fuel won't help much, if at all, as frictional and pressure losses become VERY high since the pistons (not contributing to power) still need to move air, compress it, have rotational mass, etc...not good. Simply creating drag, not power. Ever drive a 6 cylinder car with a fouled plug? Not pretty.
If you want significantly better gas mileage, sell the Maxima and get a CRX, Civic, or a Volkswagen TDI (albeit a diesel). If MPG was easily increased without penalizing performance, don't you think the automotive companies would be using the technology (they, and we, are penalized financially for not meeting CAFE requirements)? Most are embracing hybrid technology now, as diesels will face tougher emission rules soon in the U.S...emission standards are lighter in Europe for diesels, where nearly 30% of passenger cars use diesel engines.
Just shutting off fuel won't help much, if at all, as frictional and pressure losses become VERY high since the pistons (not contributing to power) still need to move air, compress it, have rotational mass, etc...not good. Simply creating drag, not power. Ever drive a 6 cylinder car with a fouled plug? Not pretty.
If you want significantly better gas mileage, sell the Maxima and get a CRX, Civic, or a Volkswagen TDI (albeit a diesel). If MPG was easily increased without penalizing performance, don't you think the automotive companies would be using the technology (they, and we, are penalized financially for not meeting CAFE requirements)? Most are embracing hybrid technology now, as diesels will face tougher emission rules soon in the U.S...emission standards are lighter in Europe for diesels, where nearly 30% of passenger cars use diesel engines.
http://www.theautochannel.com/news/2...31/022158.html
I remember the V8-6-4 in the Cadillac Seville in the 80's. I recall hearing that some of them had engine fires.
04-13-2004, 05:10 PM
#30
Senior Member
Join Date: Dec 2001
Posts: 554
You could easily alleviate the head warpage by alternating which two cylinders are shut off at a given time...
Just shutting off fuel won't help much, if at all, as frictional and pressure losses become VERY high since the pistons (not contributing to power) still need to move air, compress it, have rotational mass, etc...not good. Simply creating drag, not power. Ever drive a 6 cylinder car with a fouled plug? Not pretty.
it works. during a test, i ran stock fuel maps from 1000rpm-5000rpm in my CRX. adjusted the fuel maps for -10%@1000rpm, -12%@2000rpm, -11%@3000rpm, -13%@4000rpm, -10%5000rpm (for the vtec switchover).
also, adjusted the vtec switchover from 4400rpm to 6000rpm. one direction from Vegas to LA, i got maybe 22mpg. on the way back, got 43mpg.
04-13-2004, 06:09 PM
#31
Senior Member
Join Date: Jun 2001
Posts: 342
I get 32mpg highway and 23mpg city based on the calculation described by
rbneron. I only use the temperature.
Mike
rbneron. I only use the temperature.
Mike
Originally Posted by rbneron
The ONLY way to accurately calculate mileage is distance (on the odometer) divided by gas consumed (fill up to fill up), IDEALLY using the same pump / location for each fill up (to minimize effects of pump-to-pump variability, car not being level, etc.). Over time, the variability fill-up to fill-up will cancel out.
My '00 auto Maxima is averaging 21.9 MPG in 90+% city driving; not much different than my previous 4 cylinder Camry around town. I did not detect any increase in MPG when converting to synthetic (frictional losses in the engine are very minor relative to aerodynamic drag, tire drag, and driving technique).
The computer is trying to do the same thing for MPG calculations, but as 3Pedals mentioned, it will become more inaccurate as the actual MPG increases, as the flowrate, used to estimate fuel consumption, decreases relative to the distance travelled (the distance travelled is pretty accurate).
Also, you can't accurately average MPG by using a simple mean...you have to use the same formula above using the SUM of the distances and fuel used (this will give a different number...try it using real data). Just arithmetic mean is wrong, as distance traveled between tankfuls will vary (as a function of the MPG!).
My '00 auto Maxima is averaging 21.9 MPG in 90+% city driving; not much different than my previous 4 cylinder Camry around town. I did not detect any increase in MPG when converting to synthetic (frictional losses in the engine are very minor relative to aerodynamic drag, tire drag, and driving technique).
The computer is trying to do the same thing for MPG calculations, but as 3Pedals mentioned, it will become more inaccurate as the actual MPG increases, as the flowrate, used to estimate fuel consumption, decreases relative to the distance travelled (the distance travelled is pretty accurate).
Also, you can't accurately average MPG by using a simple mean...you have to use the same formula above using the SUM of the distances and fuel used (this will give a different number...try it using real data). Just arithmetic mean is wrong, as distance traveled between tankfuls will vary (as a function of the MPG!).
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