GTP
Deutsche Pony
- Joined
- May 27, 2015
- Threads
- 198
- Messages
- 4,441
- Reaction score
- 2,296
- Location
- Indy
- Website
- www.BambergAudio.com
- First Name
- Philip
- Vehicle(s)
- 2019 GT PP1 A10 Outrageous Orange HPDE mods
- Thread starter
- #1
The factory recommends 5w20 for my 2019 GT. DD temp is 203F.
Track day temp runs 240F max. I have no additional oil cooler.
Looking at this chart for 203F (95C) and 20-weight (=ISO 68), we see they intersect at 10 cst.
Next, I slide over to the right along the 10 cst line until I reach 240F (115C), and it intersects the ISO 220 line (237F). ISO220=40 weight.
My conclusion is that 40 weight oil on track day is the same viscosity as 20 weight oil for daily driving. 30 weight is sufficient for track morning sessions, but gets thinner on hot afternoons after the engine has been heat soaking. Adding an additional oil cooler is a good idea, especially for 30-minute sessions.
I plan to change to 40 weight for the first track day, and keep it in until the last one, then switch back to 20 weight.
EDIT: Corrections as per @StangTime.
EDIT2: more corrections.
Track day temp runs 240F max. I have no additional oil cooler.
Looking at this chart for 203F (95C) and 20-weight (=ISO 68), we see they intersect at 10 cst.
Next, I slide over to the right along the 10 cst line until I reach 240F (115C), and it intersects the ISO 220 line (237F). ISO220=40 weight.
My conclusion is that 40 weight oil on track day is the same viscosity as 20 weight oil for daily driving. 30 weight is sufficient for track morning sessions, but gets thinner on hot afternoons after the engine has been heat soaking. Adding an additional oil cooler is a good idea, especially for 30-minute sessions.
I plan to change to 40 weight for the first track day, and keep it in until the last one, then switch back to 20 weight.
EDIT: Corrections as per @StangTime.
EDIT2: more corrections.
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