Well im going to say no

1)20% is a wast in a trainer way more nitro than you need
2) car fuel has alot less oil 10-12 instead of the 18% we normally run in airplanes

Some say that car fuel has better quality oil so it can be run at lower %. Someone in my club is running there os fx 46 on 30% car fuel and im wondering how things are going to work out.. time will tell i guess...

Steven