Oil: I'm Not Convinced It Ever Needs To Be Changed

BobRip · Sep 14, 2012

I was in a Saturn dealership and they were putting a new engine in a woman's car that had only 20k miles on it. I asked what happened and they said it looked like the oil had never been changed. They were going to cover it under warranty.

Bluegill2 · Sep 14, 2012

My old L245 went 12 years without an oil change back in the late 80-2000. Missed a whole decade. Far as I know it's still running. Our old L3750 goes 5-6 years between changes and it's 26 years old

Had some old farm trucks that never got changed and always ran fine.

But I pretty much change all fluids on the newer stuff regularly.

crazyal · Sep 14, 2012

Oil analysis is done by destructive means (usually burning then identifying the light emitted) to look for what chemicals and elements are present in the oil. No engine will do this. But the computer could easily set a limit and then subtract from it for each mile or hour of use. If you are pushing hard on the pedal it could subtract more than light use. If you are pushing hard but the RPMs are not going up as the computer expects an unloaded car or truck would it could assume towing or a heavy load and make even bigger subtractions per mile. The computer could also adjust for high or low ambient temperatures and other conditions. The real question is it in the mfgs best interest to create an algorithm that gives you the longest life or one that will make sure you get to a predefined point, say 100k miles, before you start having engine issues? Also, unless it asks I don't think the computer would know what type of oil, brand, quality, or even weight (if different than the suggested weight) that's in the engine so it would have to base everything off of "their" oil.

plowindeeper · Sep 14, 2012

A friend of mine and his dad have a large logging business. They buy 2 new pickup a year. Usually put 130,000 to 160,000 miles a year on each. Most of the time they are working 3 or 4 tracts at a time plus looking at new tracts to cut. Oil is never changed or checked for that mater sometimes they pull a trailer but mostly just highway driving. Always same truck 3/4 ton crew-cab chevy/gmc 4x4 diesel. And they are always running 10-15 miles over the speed limit. Never had one to fail yet.
All there machinery get topped off 2 times a day and changed yearly though. I asked him one time why the machinery got checked so much he told me they have to last 10-15 years these trucks can be replaced for less than $10,000 a year. Some of that machinery is half a million bucks.

troutsqueezer · Sep 14, 2012

MoKelly said:
Do you really believe the oil hasn't been changed in 30 years? Really?

MoKelly

Yup, I know the guy pretty well. I believe him 100%. I'm sure he's been topping off the oil but not on a regular basis.

Gator6x4 · Sep 14, 2012

In 1974 I purchased a 1974 Chevrolet with a 454 engine. Regular as a clock ticking I would have to add a quart of oil every one thousand miles. Complained to the dealer who advised GM's acceptable standard was a quart every 700 miles. At 4000 mile intervals I would change oil and filter. I often thought about not changing the oil and only change the filter. Oil was only around a dollar a quart then so I continued changing both the oil and filter at 4000 miles.

Since the crankcase held six quarts if I had added another quart at four thousand miles instead of changing the oil and filter and instead only changed the filter I don't think the engine would have know since I would have already replaced a large percentage of the oil by adding the quart every thousand miles.

herringchoker · Sep 14, 2012

The last highway truck I owned had an N-14 Cummins engine, 460 HP. It had a small screen on the dash that displayed fuel mileage, etc. It also gave notice when an oil change was due, based on the number of gallons of fuel burned since the last oil change.

Cat_Driver · Sep 14, 2012

I went 65K with one oil change on a 1997 Ford Expedition. Now I'm over 15 year on one oil change in a Kubota tractor. YES I said years. don't know the hrs, the meter is broke.

On the ford I think I put in two or three quarts as it ran down over the three years I owned it. The kubota has not gone down yet.

I don't run all my vehicles that long, just two examples I'm personally involved with, not what someone told me about.

I go about 25K - 30K on my wifes Jeep Commander and she's turning 100K miles in a few weeks. I'm running this one till th wheels fall off. I haven't spent a dime in service other than tires, brakes, wipers etc. The Jeep runs like it did when it was new.

MHarryE · Sep 14, 2012

Caterpillar standard at Tier 4 interim is 500 hours but not sure if all product groups go by this. I think some extend longer if the customer does oil sampling.

My concern in 30 years is the quality of oil and additives ha s changed so much. Current oils handle heat and dilution much better.