Considering switching from a 10w30 to 15w40 (Delvac, Delo 400 or Rotella T)during the summer since my oil consumption increases in the summer as well as to hopefully lower the amount of engine clatter (valve train?) in my 92 3.0 V6 4x4 xtra cab. Anyone have any negative experiences using the diesel oils? Other suggestions welcomed.

 

My Company has used Toyota 4X4 trucks for many years and they have always used 15X40 oil. These trucks are really abused under very hard conditions and still have held up well over 100K miles until the suspensions have falled apart. The engines, though, have kept on ticking and many of the trucks have been sold at auction and are still running with 200K on them. I guess you could say that 15X40 hasn't had any ill effects.

Toyo Master

 

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I've run Rotella 15-40 off and on over the years with no problems. The only reason I don't run it consistently is price. Without knowing the specifics of your engine, you might also want to consider a 20w-50 for summer use in a noisy tired old engine.

 

I used to run 20-50 in my '85 22re, and my '93 pathfinder with good results. Being a bit thicker it didn't leak as much as the thinner oils would.

 

15w40 is especially designed for diesels, but I dont see any issues with using it in a gas engine--but why spend the extra money on it??

 

Like Marc P said its primarily for diesels with different aditives. I used it in an old clunker that I had, because we had it in bulk (I'm a truck mechanic) and I had problems with the valve lifters they wouldn't pump up so I went back to 10w40. but if you don't have hydraulic lifters