Favorite Oil For Fd???
 

Im curious guys........what is your favorite high-performance oil for your FDs...im thinking of changing oils.

10W40, I guess

NO NO NO - never 10-40 in a rotary (or any other car) it is the worst grade of oil to use - too many additives to produce the wide viscosity range. use 10-30 (winter) or 20-50 - Castrol GTX is the conventional oil of choice.

Redline 20-50 here in So Cal...........

So...I've been putting Castrol GTX 10w40 in my FD since I got the engine rebuilt...what exactly is the problem with this? What additives are you referring to? Why is 10w30 or 20w50 any better? Wouldn't 20w50 be a bit heavy for this rotary engine? Please cite some technical specifics so we can all benefit from this discussion :)

Lots of research and recommendations from various tuners I go with castrol GTX 10W-30 for the winter and 20W-50 for summer that is all.

Valvoline 20w50 year around in FL...Pettit uses it too.