I've used Valvoline VR1 in SAE 20w-50 in the past and have been relatively happy with it. It's inexpensive, maintains consistent oil temps, and I've heard the high zinc content is beneficial to our motors.

I have the choice of continuing the use the multi weight 20w-50 or using a single weight SAE 50 or SAE 60. What would you use? Our summer temps are getting in the 95-105F range around this time of year. I'm also going to run a 3 hour enduro this weekend. Would you use something different for an enduro vs. sprints?

If you want to spend some quality time and a lot of it with your computer; go to 'bobistheoilguy.com'

If you are racing now long enough for the motor to stabilize at the limits of the cooling systems (presumably) then a longer race shouldn't change anything. So the oil you currently use is fine.

If concerned with elevated temperature thinning whatever oil viscosity you feel is correct consider instead of going higher viscosity change to a synthetic. One of (The?) major benefits of synthetic oil is temperature stability.

Right now several of my buds are using one or another of the 'diesel' 40 wts in the race cars. Lots of zddp and other stuff although probably too much detergent.

If 20-50 is what you use and like then straight 50 would be fine in your climate (for a race car that can be warmed up).

I have used Blackstone Labs analysis including the Dyson option. While Blackstone (and other Labs) are pretty coy about one oil over another my lab reports were more focused. What I can recall would make me in your climate try something like Redline 40wt Racing.

BTW, also used VR1 20/50 and was happy.

sagoston wrote:


I have run AMSOIL 20w50 Series 2000 oil for 6 or 7 years now. I like it alot. It is expensive but worth it to me.

AMSOIL however replaced their series 2000 oil with a 15W15 Dominator oil. Same stuff with a new package.


I ran straight weight oil in my street 944 turbo for a time. Even on summer mornings cold starts were not not the best. For that reason I like the multi weight even in track cars. It can take long time to build oil temp in mornings and rarely do I have enough time to build lots of oil temp before I go on track. Remember race cars rarely see sustained 2000-2500 rpm running. This warms up the oil. Most race cars see 1000 rpm idle then 4000 to 6000 rpm full throttle.