Last winter I had the motor in my 2001 RT10 rebuilt and slightly modified.
Since then I've been using 20w50 and the car has been running great.
However, the weather here in Northeast Ohio is starting to drop, so I'm considering an oil grade switch...15w40 or 10w30.
I plan to drive the car as often as possible until the snow falls.
Any thoughts on this?

Kind regards,
JB