any one use motul 300V??? what weight?? thanx.

 

Yes, 5w40. They work great!

 

would it be a bad idea if i use 15w-50??

 

^
Yes.
The F20/F22 runs best on 30 weights.
40 weights are ok but the engine doesn't really need it, certainly not for the occasional track day.
For frequent track days an oil cooler (and sticking with 30 weights) is much better IMO.

The 15W-50 will most likely shear down quickly to 40 weight anyway.

A stable 30 weight is all you need.
10W-30
5W-30
0W-30