122,000 miles, oil never changed

[retmotor]

^ Back in the 70's even. That's neat to hear.

[Winnebeater]

Originally Posted by bluefox

I'm running synthetic in my MH and my jeep wrangler only change the oil filter at every 3000 miles and add oil to bring it back up to full. Still uses no oil. I work at the big stamping plant and they never change the oil in the press just the filters so why not my engines. It nice to do what ever I want, cause we live in the U.S.A.

I believe the difference with an internal combustion engine it has to do with the unburnt fuel and other impurities present in the blow-by. If the oil were the only factor and never came in contact with any of these contaminants I believe you could go a long time between oil changes. I imagine improved filter technologies catch a great deal of these contaminants, combine that with the improved engine tolerances and lubricant quality improvements and it adds up to much longer change intervals. On that note I have a 2000 Jeep Cherokee with a 4.0l. I change my filter every 7,500 miles and complete oil change every 15,000 running AMS Oil synthetic. 240,000 miles and counting, still has compression #'s near a new engine and runs great.

[Ron & Dee]

I don't know how you would calculate miles out of hours, but in the Air Force we ran our diesel electric generators 24/7 and never changed the oil

Ron

[Brockx]

I have used syns faithfully for 15 years in my cars and trucks. Changed oil and filter sometime above 7500 miles. Best success 1997 GMC Jimmy 4.3, sold it with 309,000 miles no internal engine repairs, never added oil. Only downer was in the late 70's tried Mobil 1 in a jet boat (454 Chevy) would not keep the lifters pumped up, drained it after about an hour.

[GuyWhoTris]

As an added benefit synthetic may get better mileage. I once did consulting work for an oil change place. I wanted to see if the additional price for synthetic had a price offset so I did a basic study on the car I was driving at the time. I saw a substantial increase in MPG. So at the end run numbing synthetic was a wash.

Keep in mind this was on one car driven in similar circumstances over 5 tanks of gas. Not very scientific I admit but would make a researcher want to look into it further.

Note I intentionally did not name the oil change company or the synthetic product because I don't want to appear to be pushing something. Just sharing my experience. For people who don't run synthetic because of the cost you may want to reconsider. In the end you may get better engine life at no additional cost.

[Brockx]

The syn will pay for itself in more miles per oil and filter change.

[RustyJC]

I've worked over 38 years in field service, technical and engineering management capacities for a large industrial engine and compressor manufacturer. In that time, I've had more dealings with lube oil situations with end users, suppliers and our in-house tribologists than I care to remember.

Because of the sheer volume of oil involved (a lube oil change in our largest units would involve over a thousand gallons of oil) and the criticality of "uptime" on these units, many of our customers will run lube oil for extended periods of time (think YEARS), BUT this is only permissible with a comprehensive lube oil analysis program from a recognized laboratory. Just changing filters does nothing to correct lube oil degradation problems resulting from:

- Shearing of VIs (viscosity improvers) resulting in loss of viscosity at operating temperatures

- Depletion of the additive packages

- Depletion of the TBN (total base number) reserve in diesel engines resulting in acidity of the lube oil

- Degradation of the lube oil base stock (yes, it DOES wear out) from oxidation and/or nitration as well as shearing of the long chain hydrocarbons

- Fuel dilution

- Coolant contamination

- Sooting in diesel engines

- Contamination by abrasives, wear metals, etc. that are finer than the filter's capability to remove them

There are other factors as well, but those listed above are just a sampling of what should be monitored in a lube oil analysis program.

As far as the original lube oil report, in addition to the wear metals being extremely high, it appears that the viscosity has dropped because of shearing of the VIs and then been brought back up to higher-than-spec levels by oxidation of the base stock.

With our engines costing from hundreds of thousands up to millions of dollars, obviously lube oil and filters are still cheaper than bearings, gears, camshafts, crankshafts, pistons and liners. At the end of the day, however, it remains your money - your choice!!


Rusty

[njs42]

Originally Posted by Diesel Guy

Hello remind me not to buy your unit.

In a modern auto, truck, or MH I do not think you can save enough time or money not changing your oil to make up for the depreciation of your vehicle real or peceived.

[screwbean]

I have worked on engines most of my life and seen the results of improper maintenance (not changing oil).
Anyone who thinks that changing oil is not necessary should visit an engine rebuild shop and look at the difference in the insides of engines.
One of the main reasons for changing engine oil is to get rid of the accumulation of undesirable compounds that form as a result of combustion in an internal combustion engine such as DIRT, carbon, acids, unburned fuel, Coolant.
Unless you are using some form auxiliary oil filtration system you should stick with the engine manufacturer recommendations for oil change intervals.

The engines in motor homes tend to work harder than in regular vehicles, so why not give them a break and keep clean oil in them, it is much cheaper than
replacing or rebuilding the engine.

[screwbean]

Well put RUSTY, we are in the same industry!
It is to bad that the majority of people do not understand the results of proper maintenance.

[Arch Hoagland]

Railroad engines never change oil either but the filter, which has to be removed with a crane, does get changed.

[RustyJC]

Originally Posted by Arch Hoagland

Railroad engines never change oil either but the filter, which has to be removed with a crane, does get changed.

There's a little more to the story than the above. Please see HERE for an example.

Rusty

[Midniteoyl]

Love how people site engines that are in constant use for thousands of hours, reserve capacities far, far larger, and in industries not related, to justify not changing oil in their engines that get 20-80 hours of use per year..

[Arch Hoagland]

@RustyJC Thanks for the link.....very informative.

@Midniteoyl...Don't know if your post was aimed at me but I didn't suggest not changing oil, I was just throwing in a comment.