My engine calls for 10w-30, and that’s all I use. It is a turbocharged performance car from the 90s, with no emissions.
The people I race with, have recommend diesel oils. Not sure I feel comfortable with that.
If your car has no emissions why would you be concerned with the usage of using a HDEO oil rated for diesel usage?
I know an abundance of Subaru folks who would go out of their way to modify their vehicles just so that they could use Rotella T6 5w40. For someone to have a vehicle that would likely accept the usage of such oil without issue seems counterintuitive.