Posted on 06/17/2008 7:19:00 AM PDT by Disturbin
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.
Yep. Generally the oil gets diluted with other lighter HCs, metal particles and water. It does need to be changed, but synthetics, aside from being synthetic, are much better for the engine with one caveat. On very well-used engines they can clean out congealed oil that has been clogging seals. This will cause oil leaks, but is a symptom not a cause. The seals were bad to begin with, the oil just caused it to be known.
Do you judge that by how it looks? Looks dirty to me after 100 miles.
I change mine a little less than 3k miles. But that is also about 6 months! :)
My owners manual states what is “normal” driving and what is not. Most driving does not fall into “normal” catagory so 3,000 is recomended. I use the Amzoil 6,000 and I am thinking to try the 12,000 next.
My father in law has one, it was his commuter car when he still working, that car has not had one single issue just oil changes and new tires when needed. I am amazed I wish I would have purchased one when he got his.
RE #2: I do the same....Mobile 1!
Another Caveat....Most people never change Transmission Fluid...If you wait past 50k...DO NOT CHANGE IT!!!
I change my oil every 50,000 miles, whether it needs it or not. My last car, I got 80,000 miles out of it before I threw a rod. But I only had to change the oil once, which was a great saving on maintenence for me.
No, it makes economic sense as well. Motor oil is nearly $3 a quart and the oils of today are MUCH better than the oils of 30 years ago. It won’t hurt your engine one bit to go 5,000 or more miles between changes. If it bothers you, replace the oil filter ever 4,000 and change the oil every 8,000.
I used to work in the business on the technical side where we would test engines for hours on end without changing the oil. This involved MAJOR oil companies and OEMs....if you’re using synthetic you can go about 7500 miles...6000 for sure. Though synthetic is expensive and not for everyone due to engine break in, etc.
I do believe 3000 miles for most people is too much, especially in engines that are 10 years old or less.
I change the oil every 12,000 miles in my Land Rover, per the owners manual.
It was a 2005 Ford F-350 ext cab dually with a 7.3 liter Powerstroke. I pulled horses, cattle and flatbed trailers. I got rid of of my livestock then started a town job and drove on average 130+ miles a day round trip to work. I retired the old gal when diesel broke $2.00 ( I thought that was high ) and got a town truck :) Glad I did.
What is it made from ?
And at 100,000 miles, your car was junk.
I have heard this but would like more info on it. My local lube shop said it won;t change the tranny fluid on any car over 100,000 miles, unless they have serviced it from the beginning. I thought that odd--what is the reason?
Thanks for posting. Good info.
I saw a a 4cyl Ford Pinto wagon with over 300K on it. The owner said he only put oil in it, never changed it. I would think that the crank case would resemble a mud pile by now. I found that using 4 quarts of regular with a quart of synthetic works fine for me every 5-6K. I’ve been told that the synthetic blend on has 10% synthetic, using the 4-1 ratio gives me 20%. When I replace a quart, I add a synthetic. Usually go 4-5k before I add a quart. 4cyl with 100k on it.
Please see post # 13. Your answer is there.
-I got 80,000 miles out of it before I threw a rod-
I’ve never had a car go bad with that low a mileage; maybe should have changed the oil, :}
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