Do you see ANY reason NOT to use the 15w-40 motor oil that is so commonly used in diesel engines.. Forget about the weight of the oil, I am more concerned with the additive package that is unique to these oils... Someone told me that the extra additives will eat away the seals in gasoline engines.. Truth or BS?

 

If I remember correctly, there are additives in the diesel oil that are detrimental to the catalytic converter in a gas powered vehicle. My company was trying to use it in the newer "close tolerance" engines, and we had engine failures due to the delay in getting oil flowing to the top of the engine (oil is too thick when cold)

Thats 2 reasons not to use it.

 

Where I work, we use 15w-40 "all-fleet" Valvoline motor oil in ALL of our trucks, which includes big diesel tractors, diesel Ford 250/350 vans, 6 and 8cy gas E series Ford vans, and we even have a few Ford Focus' and 2 Tacoma 2wd's. We have Ford E series vans with 200-500 thousand miles on the clock with no problems.

 

been running 15w40 in mine since I've owned it. No problems at all... I actually prefer 15w40 just a little thicker then 10w30.

What do you drive with what engine? I have 90 3.0 that I use it in.

 

I run 15w40 in my 22re and I"m pretty sure Kyle_22r runs it in his truck as well.

 

I run 15w-40 Rotella in both my diesel K5 and my Toyota. No side effects at all, and it helps that its pretty cheap when you buy in bulk.

 

Fine to use as long as the diesel (or universal) oil has both a "C" and and "S" rating. C is for Compression ignition engine use, S is for Spark ignition engine use. I've run Shell Rotella, Mobil Delvac and Texaco universal oils in my 4Runner, they work fine. I also have a VW diesel and use the same oil in it.

 

i used to use it when i first built my engine, but currently run amsoil 10w40. after this winter i'll try the amsoil 15w40 for summertime abuse. the 15w40 delo i was using in the winter was a little too thick for my liking for the temperatures we had(dipping under 20 degrees a bunch in january). would be a great summer oil though.

 

4crawler nailed it on the head.

 

Thanks everyone!