do not put 6qt with APS. I have APS TT and 6qt was too much.. there were smoke in the engine bay (car trying burn off extra oil or sum'n). I recommend 5 qts. Mobile one 10-40 seems to be crap, raising my oil temp about 15 deg. Bought some royal purple 10-40 for my next change. Post above about RP spinning the bearing seems a bit discouraging

 

Cool thanks for the info guys, sounds like ill be buying Amsoil 10w-40 and only put 5-5.5 qts in. I'm learning new stuff everyday.

 

I would run 10w-40 or 20w-50 as the heat from the turbos is going to thin the oil out further. Good thread btw. This is a good question.

 

I never had a problem with Mobil 1 10w-40, but i don't have a oil temp gauge... so i am not sure

 

Ive ran M1 10W30 synth extended performance here in 100F Houston summers and have no problems. This will be my built motor's 3rd summer at 34k miles.

IMO, if your motor and bearings are in good shape, a good quality 30 weight oil should be fine. Maybe a 40 weight if your well into the 500 whp/wtq. Its how well the oil holds up to the high temps in the turbos is whats important.