RE: Nitro Fuel
traxxas 20% is the safest fuel to run and does the best in trx engines in my opinion. i run all sorts of fuels in many different engines. personally, i like nitrotane for my savage 4.6 and traxxas is great for high temp areas like mine.
traxxas fuel goes best with traxxas engines.
10% is best for the .15
20% is best for normal running with 2.5 or 3.3
33% is best for racing with any trx engine but it lowers overall engine life.