Oil Change Interval

[TeJay]

Daveinet,
Very interesting information concerning oil and the additives that are involved. I was aware that the additives would wear out and which would render the oil useless at least as far as protecting the engine.
The S ratings. They (somebody) changed those ratings back in the late 60's I think to the SA, SB, SC, SD etc. It was changed so as the additives changed they could just change the second letter. From what you said the additive companies change the additives then the auto industry adopts the new ratings and the extra protection they offer. Is that about what happens??
It still seems to me that the auto companies are at the mercy of the API and the additive companies. If the oils don't hold up the engines would have to be warrantied by the manufacturers and not the API or the additive companies.
What do the additive companies do for the synthetic oils??? Do they fall into the same catagory as regular oil??? It was my understanding that synthetics went through some molecular adjustments which made them withstand more abuse and could therefore reduce friction to a greater extent.
Can you shed some light on these topics??

Thanks,
TeJay

[Daveinet]

I'm going to make a guess based on other things that I know about Mobile. My gut feeling was that Mobile got real tired of always being behind in product development, which motivated them to invest in an alternative, so they could meet spec without being forced to purchase their competitor's additive. This way they at least had one product that was all their own that would meet spec. They may have exceeded spec and were able to ride the wave for some time. The spec is a minimum, so a synthetic could exceed spec by a small amount or large amount. If there are properties that enable the oil to last much longer, they would match rest of the additive package longevity, assuming they can.

You pretty much get how the rest of it works. Historically the additive companies drove the API ratings, however when the EPA required emissions to last for 150K miles, there was some mutual work between the automotive manufacturers and the additive developers. Interestingly, ZDDP was blamed for clogging the catalytic converter, however there was no laboratory testing to prove ZDDP content was at fault. The automotive manufacturers basically just dictated what they wanted, and the additive companies developed products to meet their requirements.

The real ugly part is that the EPA claimed a requirement of backward compatibility for older engines, however the testing was done on a fairly small engine with 1/3 the valve spring pressure as a stock 454. So the backward compatibility test was completely bogus. That and it only had to meet some minimum requirement, not necessarily be as good as the older oils. So ya, if you run an older engine, you need a ZDDP supplement in your diet.

[jrgreenacres]

If your going to use another authors statements please have the common courtesy to state their names and don't take their statements out of context.

[George Schweikle]

Here's a new gadjet claiming cheap oil analysis. It may be snake oil, but I bought one just to try. BTW, I use Mobil 1 in my 454, and change once a year or 5000 miles, whichever comes first. We almost always tow a 5000 lb. car trailer and oil usage depends on how heavy the engine is run; flatlands @ 60-65 MPH hardly any use, heavy mountain driving, more frequent. Maybe 1/4 quart every tank of gas. The engine has 77,000 miles.

Lubricheck - The digital 'blood tester' for your car

[Daveinet]

I would view that Lubricheck as a great tool to use when purchasing a used vehicle. One could also use it to detect problems before they arise, however I did not see anywhere that it is capable of measuring ZDDP content or any other additives. If it can't detect additives, only contaminants, it is only telling you of a problem after the fact. In theory one could measure metal, but how do you judge? Do you take periodic samples and graph your results. When you see a sharp rise in the rate at which the metal content is rising, you know the additives in your oil are depleted? That does not seem like the way I would want to play the game. I like the device and my actually pick one up, as I tend to occasionally purchase used vehicles, but I don't know that I would use it for determining oil change intervals.

[Soxs]

This is the first oil change. We bought a used coach and just getting to know it.

[Max Hubrich]

Soxs-

If your changing it yourself, which I do, I'd like to make a suggestion-

You can pre-charge the oil filter with about a 1/2 to 3/4 of a quart of oil by slowly pouring the fresh oil into an upright filter. It will proglong your engine life by avoiding a "dry start".

A neat tool is a battery operated grease gun. I bought this Milwaukee one. I can use my drill batteries in it. There are many grease (Zerk) fittings on our rigs and it is so much easier to use this grease gun. It makes the job almost a pleasure (I said almost).
"Driver" aka, Mike P, always recommends we lift the weight off the front suspension to grease the ball joints. Use your leveling jacks for that-

Don't forget the drive shafts on a 38' motorhome.

Good luck,

[wa8yxm]

Annually with Durablend.

NOTE: with the better quality oils, If you send a sample to the lab (Take sample on the way to the oil change, or if you do it yourself from the draining oil) They can tell you if you are doing it often enough or not.

Odds are if you use High Quality, Highly Refined oil (Most "Synthetics" are this kind of oil.. A couple are really synthetics, but most of what is sold as Synthetic is really "Synthetic" (With quotes, Highly refined Dino oil).

Odds are.. You can go longer... But.. ODDS are, just that, ODDS, and thus you MUST test to be sure.

Lab can often find developing issues with the engine from what's contaminating the oil by the way.

[Soxs]

Max,

Thanks for the info! I wish I had read your post, prior to changing the oil.
Filling the filter sure would have helped in the refilling process.
The greasing another, should have used the front jacks to give myself more room to maneuver and get to the grease fittings.

Soxs

Originally Posted by Max Hubrich

Soxs-

If your changing it yourself, which I do, I'd like to make a suggestion-

You can pre-charge the oil filter with about a 1/2 to 3/4 of a quart of oil by slowly pouring the fresh oil into an upright filter. It will proglong your engine life by avoiding a "dry start".

A neat tool is a battery operated grease gun. I bought this Milwaukee one. I can use my drill batteries in it. There are many grease (Zerk) fittings on our rigs and it is so much easier to use this grease gun. It makes the job almost a pleasure (I said almost).
"Driver" aka, Mike P, always recommends we lift the weight off the front suspension to grease the ball joints. Use your leveling jacks for that-

Don't forget the drive shafts on a 38' motorhome.

Good luck,

[Soxs]

Thanks for the information!!

[DAN L]

SOXS,
please do not go under your moho with it raised on your leveling jacks.
i always use jack stands in case of a problem.

[Brockx]

Originally Posted by DAN L

SOXS,
please do not go under your moho with it raised on your leveling jacks.
i always use jack stands in case of a problem.

Amen to that, my neighbor and I were standing next to his Allegro when a line ruptured, fell like a stone.