We're running an FC (88, AE per signature below) in SCCA auto-x and we might do some HPDE events. We currently have 10W30 Amsoil in the car (from the winter). We are upgrading our oil cooler lines to stainless and as part of the process, we are going to change the oil. We're new to rotaries so it is important to us not to make a mistake with the grade of Amsoil we choose. Our first inclination is to use 20W50 because of the warmer weather between now and September. We are worried that it might be too heavy. Please give us your suggestions.

 

I use Valvoline Racing 20w50 in my FD. I don't use synthetic but that is a whole debate in itself. There have been many threads on oil usage. If you search you will come across them.

 

Valvoline 10w40 in the summer and changed often to avoid gas dilution. Definitely changed before each track event. I don't believe that synthetics hurt, but I consider it more important to change oil often, so I don't personally believe that synthetics would make a significant difference.

-bill

 

Castrol GTX 20w-50 for the summer months. 10w-30 for the winter. I sometimes stick with 20w-50 all year long, because my car isnt driven as much during the winter. Thats for a turbo car though. For something NA I would say 10w-30 year round

 

Castrol 20x-50 is fine for street driving. In my race car, I use the Valvoline VR-1 20w-50, because it foams less at sustained hi-rpms that my peripheral port road racer stays at.

 

Probably just stick with Castrol GTX 20w-50 or Valvoline VR1 race oil if this is the original engine. I have well rebuilt engine and have used cheap dino 5w-30 for break in, then Royal Purple Racing 21, and now a special German Castrol that appears like a 40-wt. The Royal Purple sample is out to Blackstone Labs for testing right now, and we'll do the Castrol in another 1K miles or so. If your Amsoil appears to be working for you, then keep using it......the GTX and VR1 seem to provide good protection and burn cleanly-- the higher flash point of the Amsoil *may* cause some housing deposits or fouled plugs, but if its working for you and oil analysis shows nice low wear and low fuel dillusion, then keep using it.

 

James, where would I get an oil analysis done out here in KC country? I've never heard of that before. Please enlighten me.

 

Blackstone labs does oil analysis for 20 bucks a pop. Google their site

 

how often do you(should you) change oil, with 10w30?