Aviation oil is to 60 wt.

Be careful, some racing oils are just that. Only antiwear additives,little if and dispersants. they expect folks to change oil after every race.

Multi weight is better cause 90% of wear comes during warmup.

When you look at the cost of say Redline got to compare the "difference' in price.

I run synthitic oil in every engine I own from Dixie Chopper to Dodge Cummings to Honda Accord to, Harley. Some I change the oi every year or so.