With the increasing torrent of 'environment friendly' oils replacing trusted ones, getting difficult to match one to older engines. AC operators manuals clearly stated that low sulphated ash oils were NOT to be used in 6000-11000 engines. Military spec was MIL-L-45199A which I can't find any reference to. Looking at specs of oils, medium or higher ash seems accompany higher calcium level (and alkalinity), higher levels of anti wear additives phosphorus and zinc, and higher TBN. They seem to be only recommended for European and Japanese truck engines. Would they not suit the AC engines?

Posting this here because more guys with experience in oil testing and analysis seem to chime in than on construction section.

Study the API Spec system and look to a Caterpillar heavy equipment dealer for oil sampling support. maybe even consider purchasing their oil if it fits the spec.

There are so many different types of specifications now days and lots of conflicting specs from engine manufacturers. I recently had to find oils for a couple machines at the construction company I work for. 

In talking to the representative from the corporate side of our oil supplier he said the reason there are so many new specs relates to optional extended warranty coverage and that standard warranty will allow you to use off the shelf products but optional extended warranty can make coverage conditional on the use of specified fluids.  

Lots of the newer engines want lower viscosity oils for cold starts and fuel economy and the newer engines will live or maybe thrive on them. I tend to think this is the right prescription for the newer engines since the MFG is willing to pick up the repair tab.

I ran into a European spec that was not  backward compatible to any API spec and that was a surprise to me.

steve(ill) wrote: I would think a new 15w 40 Diesel oil would do fine in the old tractor.  Lots of guys of ALL brands using new spec 15w 40 Diesel oil.

I've used 15W-40 diesel grade oil in every motor I own from 1 cylinders on up for at least 20 years.I don't have any newer vehicles or tractors though.

bigal121892 wrote: Can't use multi-viscosity oils in IH engines, they will use couple of gallons a day if you do.

I use 15W-40 in my IH 464 with no problems

There have been 'oil threads' on the Red Power board that got rather ugly. People pretty passionate on both sides. The little I have read of them I just decided to run CaseIH 30 Wt. in my 1066. With the amount of hours I put on the old girl my savings for using bargain oil would be a few $$ a year at best. If you have to change a cam and lifters because of bad oil that gets into money.

I use a lot of 15-40 Rotella in other things.

Not an opinion, comes straight from the dealer. Had 1480 combine, was using two gallons a day, dealer told us absolutely no multi-viscosity oil, only use straight 30. 

Thanks jeickman, That sheds some light on the subject for me. It would perhaps be a mistake to go to the higher ash Euro/Jap engine oil in my old tractors after they have ran on low ash Caterpillar/Cummins suited oils.

Something I liked the look of in that higher ash oil though, was the higher level of anti wear additives Phosphorus and Zinc, which seem to be declining in modern oils.

Not trying to argue with you, but that just seems and sounds very odd!  WTH does multi viscosity have to do with using oil, other than the top end of the engine is in terrible shape, and usage would be during start up and warm up????  Just sounds like a very odd statement...

sure simplifies oil buying.  I figure it is a step above gas engine oils with high detergents plus the higher pressures of diesel engine.  I have had no problems yet  knock on wood.

I did that about 20 years ago,so far so good.

Dad bought the combine used from the local dealer, we got it home, changed all of the fluids, and put 15W40 in it just like we had in everything else. Combine used two gallons of oil the first day. Called dealer, (thinking we were sold a combine with a bad engine) dealer said drain the 15W40 out, and put straight 30W in. Did that, and the combine would use a quart every 100 hours until it was traded 3 years latter.

For any diesel or older gas engine, I would recommend it.

Grandpa bought a Cat diesel tractor in 34, with the dealer being able to bring other customers around to show off the new diesel engine. Started burning oil right from the start. Not what Caterpillar company or the dealer wanted,or grandpa for that matter. Was the newest high tech of the day, but unproven at the time. The bolts about learned to unscrew themselves they had that engine apart so many time. After new rings, then pistons and rings,and finally sleeves,pistons,and rings and a brand new oil with detergent it ran without oil consumption. 

The detergent oil was developed to help remove the carbon and other by products of burning low grade fuel, that we know today as diesel fuel.If ever a engine needed detergent oils its diesels.

Will not get into the straight or multi weight oil argument. But have been convinced by a engine machest that we don't need as much oil pressure to keep a engine going as we generally think.

I mainly use the tractor for brush hogging, so I thought a straight 30w would be ok. Don't use it during winter pos.

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