Timely Oil Changes

Daveinet wrote:

427435 wrote:

jhilley wrote:
I run about 6,000 miles between oil changes and have the oil tested at

Blackstone Labs

The tests confirm that I could go a little farther between oil changes, so 7,500 miles should be ok. This is with quite a bit of mountain and hot weather driving pulling a Jeep Cherokee.

It is good to get an oil analysis just to see how your engine is wearing.

X2

Having your oil tested is the smartest way of doing it.

I'm not sure I understand the usefulness of this test as it relates to change interval. I see no place where it tells you how much additives are still in your oil. while it gives an indication of wear, it is telling you after the fact. for example, how do you know if the oil still has enough zddp in it? if you are starting to see increased wear, you are finding out after the fact - after the increase has occurred is too late.

Same as medical screening tests. It will also give you recommendations for rectifying the problems detected, such as checking the air filter and intake if too much silicon is detected.

This is comment from one of my tests

"JOHN: Universal averages show expected wear levels for the Ford 6.8L V-10 after ~4,500 miles. You ran longer and
that's part of the reason iron is higher than average because iron will accumulate in the oil during a longer oil run. But
we also suspect silicon may be a little dirt in your engine and that could have caused the extra aluminum and some of
the iron, perhaps. Change your air filter to see if that takes care of it. Otherwise, this sample is in fine shape. The low
viscosity and trace of fuel are harmless. The TBN of 2.3 is good since 1.0 is low. Try 7K miles next."

It doesn't show the additives left, but it shows what is controlled by additives and whether or not they were with in normal ranges. As far as wear, how would you predict in advance? This tells you before your engine is ruined.

427435 wrote:

jhilley wrote:
I run about 6,000 miles between oil changes and have the oil tested at

Blackstone Labs

The tests confirm that I could go a little farther between oil changes, so 7,500 miles should be ok. This is with quite a bit of mountain and hot weather driving pulling a Jeep Cherokee.

It is good to get an oil analysis just to see how your engine is wearing.

X2

Having your oil tested is the smartest way of doing it.

I'm not sure I understand the usefulness of this test as it relates to change interval. I see no place where it tells you how much additives are still in your oil. while it gives an indication of wear, it is telling you after the fact. for example, how do you know if the oil still has enough zddp in it? if you are starting to see increased wear, you are finding out after the fact - after the increase has occurred is too late.

jhilley wrote:
I run about 6,000 miles between oil changes and have the oil tested at

Blackstone Labs

The tests confirm that I could go a little farther between oil changes, so 7,500 miles should be ok. This is with quite a bit of mountain and hot weather driving pulling a Jeep Cherokee.

It is good to get an oil analysis just to see how your engine is wearing.

X2

Having your oil tested is the smartest way of doing it.

I run about 6,000 miles between oil changes and have the oil tested at

Blackstone Labs

The tests confirm that I could go a little farther between oil changes, so 7,500 miles should be ok. This is with quite a bit of mountain and hot weather driving pulling a Jeep Cherokee.

It is good to get an oil analysis just to see how your engine is wearing.

Wow. Lots of new, old, bad, and good stuff here.
Since it is mostly anecdotal, I'll add my own.

My motorhome (cummins ISC) manual says 15k or annual.
First year we did 15k, and I changed the oil.
Second year we did barely 6k, I changed the filter.
Third year, barely 3k, changed nothing.
This spring, (2 years and 5500 miles, I will change the oil and filter.

Now on to anecdotal...
My 2000 Jeep wrangler has 272,000 miles on it, up from 212k when I bought it 5 years ago.
I go 10k plus between oil changes and use dino oil.
Even then, that AMC 4.0 inline 6 uses no oil between changes, not a drop.
My "plan" is if I can blow it up, I can replace it, either with a Golen 4.6 stroker, or a Chevy 5.3, depending on my feelings at that moment.

But that old six just says *uck you Jim, I can take it, and I will. I will outlast you!"

For the most part, oil change intervals do nothing but guarantee the profits of those selling the oil and the filters.

Sometime in the future, when I've nothing better to do, and money matters a little more, I'll have my oils anylized, and replaced only when they come up "Shot"

stubblejumper wrote:
Oil does not go bad it has been underground for millions of years! additives deteriorate and contaminants get into it. Oil can and has been recycled for years by being filtered and having new additives added.
If the rings on your pistons are not loose or worn allowing blow back, you should not get "soot" in your oil. Most contaminant in oil results from heat burning additives and residuals from engine wear and dust. At Husky we used to sell recycled oil at a lower price. Oil and antifreeze are recycled in Alberta, picked up regularly from service centers by recyclers.

Tests done in 2004 showed new engines have shown 6 to 7% soot content in the oil in 12K miles as a result of EGR.

As others mentioned read the manual. Mine states at least every year. There is some talk about doing it before you put it away for the winter ( for those who do ). I plan to do it after bringing it out in the spring.

stubblejumper wrote:
Oil does not go bad it has been underground for millions of years! additives deteriorate and contaminants get into it. Oil can and has been recycled for years by being filtered and having new additives added.
If the rings on your pistons are not loose or worn allowing blow back, you should not get "soot" in your oil. Most contaminant in oil results from heat burning additives and residuals from engine wear and dust. At Husky we used to sell recycled oil at a lower price. Oil and antifreeze are recycled in Alberta, picked up regularly from service centers by recyclers.

Doesn't matter how new or well built the engine is there is always some blow-by. If you don't believe that try sealing up the crankcase, no PCV, etc. then see how many oil leaks develop.

As mentioned, reading your owner's manual is a good place to start. Keep in mind that most owner's manuals mention "normal" and "severe" duty operation of the engine. Most all RV's are considered being operated in the "severe" duty since that are almost always being operated at close to the maximum carrying capacity of the chassis. Towing is considered "severe" duty. Using the recommendations in my WH manual, my RV needs the oil changed at the 3000 mile intervals rather than the 7500 mile interval recommended for engines doing light duty.

stubblejumper wrote:
Oil does not go bad it has been underground for millions of years! additives deteriorate and contaminants get into it. Oil can and has been recycled for years by being filtered and having new additives added.
If the rings on your pistons are not loose or worn allowing blow back, you should not get "soot" in your oil. Most contaminant in oil results from heat burning additives and residuals from engine wear and dust. At Husky we used to sell recycled oil at a lower price. Oil and antifreeze are recycled in Alberta, picked up regularly from service centers by recyclers.

^x2