the 3,000 mile oil-change myth.....

[ROCKART]

http://autos.yahoo.com/articles/auto...MzMDAwLW9pbA--

According to a recent study by the California Integrated Waste Management Board, 73 percent of California drivers change their oil more frequently than required. This same scenario no doubt repeats itself across the country. Besides wasting money, this translates into unnecessary consumption of $100-a-barrel oil, much of it imported.

Using 2005 data, the Board estimates that Californians alone generate about 153.5 million gallons of waste oil annually, of which only about 60 percent is recycled. Used motor oil poses the greatest environmental risk of all automotive fluids because it is insoluble, persistent, and contains heavy metal and toxic chemicals. One gallon of used oil can foul the taste of one million gallons of water.

It’s been a misconception for years that engine oil should be changed every 3000 miles, even though most auto manufacturers now recommend oil changes at 5,000, 7,000, or even 10,000 mile intervals under normal driving conditions.

Greatly improved oils, including synthetic oils, coupled with better engines mean longer spans between oil changes without harming an engine. The 3000 mile interval is a carryover from days when engines used single-grade, non-detergent oils.

For several years, automakers like General Motors, BMW, and Mercedes-Benz have installed computerized systems that alert drivers via an instrument panel light when it’s time to change oil. As an example, the General Motor Oil Life System (GMOLS) analyzes the engine temperature, rpms, vehicle speeds, and other driving conditions to calculate the rate of engine oil degradation. Then, software calculates when the oil needs to be changed. Other systems work similarly.

Because of the many external conditions and parameters that have to be taken into account, calculating the precise maximum service interval using mathematical models alone is difficult. Now, Daimler AG has developed a more direct and precise way to monitor oil quality directly on board a vehicle.

Daimler uses a special sensor integrated into the oil circuit to monitor engine oil directly. Oil doesn’t wear out, but rather dirt and impurities cause oil to lose its ability to lubricate properly, dictating the need for a change. Daimler uses the oil’s “permittivity,” that is, the ability to polarize in response to the electric field. If the engine oil is contaminated by water or soot particles, it polarizes to a greater extent and its permittivity increases.

To evaluate the quality of the oil, permittivity is measured by applying an AC potential between the interior and exterior pipes of an oil-filled sensor to determine how well the oil transmits the applied electric field.

Because not all impurities can be measured with sufficient precision via the electric field method, Daimler also measures the oil’s viscosity to detect any fuel that may have seeped into the oil. Daimler researchers measure viscosity while the vehicle is in motion by observing the oil's side-to-side motion in the oil sump. The slower the oil moves, the higher its viscosity. This movement is registered by a sensor and the viscosity is calculated on this basis.

A single sensor, along with the information already monitored by on-board computers, is sufficient to determine the various parameters of the engine oil. Daimler will likely use the technology first on its commercial vehicles. Here, large oil reservoirs mean larger quantities of oil can be saved. Plus, a predicted 25 percent increase between service intervals and reduced downtime will be of interest to fleets, and thus justify the added cost of installation.

interesting to note, especially because of how many of us on this forum compulsively change our oil (i use dino oil, castrol 5w-30).


*tangent
i used mobil 1 synthetic for my first two oil changes, from 40k to 51k, but then was told by a Nissan tech that it was contributing to a "noisy" engine (the loose metallic clicking noise). he suggested i try running castrol for a couple of cycles, just to see if there was a difference; there was, a huge one. my engine was, id say, 20% quieter with the dino in place of the synthetic.

[internetautomar]

Very few people drive their car under "normal" driving conditions. most driving falls into the "extreme" driving condition definition.
I'll stick to changing my oil every 3k or so, and not worry about the detrimental effects of extending oil change intervals on my engine.

[sascuderi]

I have always used synthetic in our Nissan cars (maxima, Murano, I30) and changed the oil only once a year. (usually 8-10K miles driven each year). Currently using Mobil-1 EP Synthetic and Mobil-1 filters in all our cars. Knock on wood, no problems yet.

[mrkanda]

Originally Posted by internetautomar

I'll stick to changing my oil every 3k or so, and not worry about the detrimental effects of extending oil change intervals on my engine.

Ya, but what about the detrimental effects on the environment, global oil reserves, and your pocket book?

[Mr3Putt]

every 7,500 Mobil 1. Never a problem.

[VQrebuild96]

Originally Posted by mrkanda

Ya, but what about the detrimental effects on the environment, global oil reserves, and your pocket book?

lol u sound like my cuzin.. always thinks its a rip off to get your oil changed. he use to change his every 7k or so. And we both had the same cars honda civics same engine b18. I changed my oild every 3k. We do drag racing and race hard. we revved to 11k pushing the limits. He blew 3 engines and i was still on my first and i know its because i change my oil... but that was along time ago who knows im just saying if u drive like a grandma fine change ure oil wenever but if ure engine is seeing 6.5krpm daily change at 3k.

[Cinnamint]

Or use amsoil and change it every 15k miles.

[SilverMax_04]

The safest solution is to get a lab check of the old oil when you drain it out. I did that on my last change and found that even at 9 K miles there was still life remaining in my Mobil 1. I am now pushing 10 K miles on this oil and will change it before I depart on a long trip. I will send in a lab sample this time -- and every time I change.

When I changed the oil on my Dodge truck, the lab found there was antifreeze in the oil. I would never have known about the slow antifreeze leak that was happening in both heads of the engine -- had I not done a lab test of the oil.

The money for a lab test is money well spent. And having the results will keep you from discarding motor oil that has remaining life.

[maximabebe]

I bought my car with more than 100k miles on it and it became habitual to change my oil at 2500k intervals using synthetics. Might be overkill, but to me its an insurance policy.

[Scottwax]

Mobil1 every 6000 miles.

When I had my Chevelle, I used Valvoline (dino) oil and changed it every 2500 miles. I got a different engine when the old one had 95,000 miles on it (more compression, better rods, etc) and when we tore down the old engine, other than the lack of cross hatch in the cylinders, it looked like a brand new engine. No sludge, no buildup, the oil pan was spotless. No ridge at the top of the cylinders and all it needed was a clean-up hone. Bear in mind that this engine saw twice monthly bracket racing from 55,000 miles all the way to when I pulled it.

Oil is cheap insurance, IMO.

[talkinghorse]

People often ask me about OCI's and I routinely advise them that they have to do what they're comfortable with. If you search this site, you will find almost as many opinions as there are members.

The fact of the matter is that the industry as a whole is moving toward extended drain recommendations due to better engine design, better materials, better oils, and environmental concerns. It's also important to note that not all oils are created equal...generally speaking, synthetics will outperform and outlast their petroleum counterparts, and there are even vast differences in quality between manufacturers of synthetics. Some synthetic oils, such as AMSOIL, contain robust additive packages that provide superior wear protection and are specifically designed to maintain their protective properties over extended drain intervals. Combine a premium oil with premium air and oil filtration and you have a great combination that will provide reliable service over the long haul.

Will it hurt to change your oil more often than necessary? I would say not, but over the next several years, we will definitely see the industry move toward extending intervals even further than they are recommending today.

[meccanoble]

Originally Posted by maximabebe

I bought my car with more than 100k miles on it and it became habitual to change my oil at 2500k intervals using synthetics. Might be overkill, but to me its an insurance policy.

woah! You change SYNTHETIC ever 2500 miles and from what I see you arent boosted or anything? I would love to be the next owner of the car but that sounds like a serious waste of money...

[ROCKART]

thats a sick 5th gen. nice job.

[Grimsta]

There are several myths and misinformation here. Regardless of what oil companies and auto manufactures say the only real way you can tell what your service interval should be is by analyzing the oil. I have a whole diseration to post up that will clear up several of these myths. I dont care who makes the oil, AMSoil, Redline, or Eneos, no oil should ever go for 15K. Or even 10K. Never go more than 5K or 7K if you really are just forgetful.
Once I acrue more posts i'll post up all that information for you guys in another thread

[maximabebe]

Originally Posted by meccanoble

woah! You change SYNTHETIC ever 2500 miles and from what I see you arent boosted or anything? I would love to be the next owner of the car but that sounds like a serious waste of money...

It may very well be a waste Mecca...but I know I won't have any problems with it. Keeps my head screwed on straight.

[SilverMax_04]

Originally Posted by maximabebe

It may very well be a waste Mecca...but I know I won't have any problems with it. Keeps my head screwed on straight.

I just received my second lab report on my oil extended oil change interval. For both changes, I went just short of 10 K miles. The lab says that I could have gone further on my Mobil 1. But I like to start a long trip with fresh motor oil. I doubt if I will go further than 10 K on any single oil change (for then I would need to change the filter in the middle of the oil change interval). Still, only going 2.5 K miles is a waste of good synthetic motor oil. Push it a little further (at least to 5 K miles) and if this worries you, send in a sample for a lab test. I did not get my first lab test until I went from 7.5 K miles to 10 K miles per oil change. I made that change when the extended power train warrenty ended (as Nissan's miximum OCI is 7.5 K miles).

[Turbobink]

I've said it before and I'll say again and again... However, I do realize the merits of the UOA. That truly is the best means of determining your OCI.

Originally Posted by Turbobink

if you maintain your car and change the oil regularly at the manufacturer recommended interval you will realize absolutely no performance or protection benefits by using synthetics.

on the other hand if you're a street, circuit, or auto-cross racer; if your car is turbo'd or supercharged; if you typically extend your drain interval; or if you drive in some seriously nasty conditions of heat and cold (NJ summers and winters don't count as seriously nasty in the world of motor oil), then synthetics may be a benefit... primarily if the drain interval is extended.

change your oil every 3000 miles, use a high quality conventional oil and a high quailty filter and save your money.

[Tmax156]

I used to have a 06 Titan and I did 5000 mile oil changes no problems but since I have gotten my 00 max its been 3000. Now i think I will go back to 5000,thanks for the info.

[NIKV69]

Very few people drive their car under "normal" driving conditions. most driving falls into the "extreme" driving condition definition.
I'll stick to changing my oil every 3k or so, and not worry about the detrimental effects of extending oil change intervals on my engine.
__________________

Well said

When I used mineral oil I changed my every 3000. I changed to Mobil 1 and now I go 3000, change the filter and go another 3000. It is a small price to pay to keep you engine clean inside.

[Snypa]

Originally Posted by NIKV69

Well said

When I used mineral oil I changed my every 3000. I changed to Mobil 1 and now I go 3000, change the filter and go another 3000. It is a small price to pay to keep you engine clean inside.

Are you saying you change your filter every 3k, but oil every 6k?

[talkinghorse]

Originally Posted by NIKV69

now I go 3000, change the filter and go another 3000. It is a small price to pay to keep you engine clean inside.

Originally Posted by Snypa

Are you saying you change your filter every 3k, but oil every 6k?

That's exactly what he's saying; and while it might be a matter of personal preference, it's unnecessary.

The only reason you would need to change the filter is if you suspected it were clogged. If the filter were clogged, the pressure drop across the filter would cause the by-pass valve to open, allowing dirty/unfiltered oil to bypass the filter and go directly to the engine. That's simply not going to happen in 3000-6000 miles in a well maintained Nissan engine, running synthetic oil and using a quality filter. A fresh filter every 3,000 miles isn't going to be any more efficient than the one removed.

[SilverMax_04]

Originally Posted by talkinghorse

A fresh filter every 3,000 miles isn't going to be any more efficient than the one removed.

That is correct.

So many people on this site think that they are being "good to their car" by changing the oil (or the filter) before it is needed. [And, of course, the type of driving you do does make a difference -- particularaly if it is on dusty dirt roads for most of the miles.]

But most of the posters here change their oil "before its time" thinking that it will "help their engine." It only helps the oil change people (unless you do it yourself). All of you need to send in a sample of the drained motor oil for a lab test -- to see what quality you are discarding when you change oil too soon.

Under normal city type driving, I recommend the following OCIs -- but at least once a year, independent of mileage:

- Good quality dino oil and good quality filter -- every 5 K miles (or more).
- Good quality synthetic oil and filter -- every 7.5 K miles while under Nissan power-train warranty, then every 10 K miles thereafter.

Try this with a lab test and you should see that even with these extended OCIs, you are still discarding motor oil with some remaining life. I know because there has always been life at 10K miles in my drained Mobil 1.

[antslake]

Originally Posted by Grimsta

There are several myths and misinformation here. Regardless of what oil companies and auto manufactures say the only real way you can tell what your service interval should be is by analyzing the oil. I have a whole diseration to post up that will clear up several of these myths. I dont care who makes the oil, AMSoil, Redline, or Eneos, no oil should ever go for 15K. Or even 10K. Never go more than 5K or 7K if you really are just forgetful.
Once I acrue more posts i'll post up all that information for you guys in another thread

Sounds logical, I would like to see that information.

I own a 94 Astro van with 225,000 miles. I only changed the oil every 10k. When I had 175k on it, I switched to amsoil. I saw a mpg increase, and only burned 1 quart after 13k miles. It still doesn't really burn oil, and the engine runs great.