Okay i want to step in here. i have a guy who has been in this for a while who custom blends my fuel. My mix is 25% nitro and 3% benol and 5% Klotz. so just 8 % .
i used to use 18% oil hobby shop fuel, it is too much for me, it makes little horsepower and revs slowly and it is also hard to get it nice and lean because it has so damn much oil, i lean my engine until it stalls under acceleration then back it off 1/4 of a turn. dont worry about this method hurting the engine because it will cut out as soon as its too lean (equivalent to running the tank dry) and another 1/4 turn richer gives PLENTY of margin for error (ie will not starve for fuel).

with 18 % oil it is very hard to get this right. and as with traxxas fuel, my mate runs normal 18% oil store bought fuel and it runs sweet as, even on my 8% oil blend it runs cool.
i have a crazy idea, maybe traxxas say that so you spend more money with them...?
If you rad the OS engine manual it says a recommended 12% oil and the novas are usually 10%, i run even lower mainly for performance, like white lightening its low but definately enough. especially seeing as how its angus nitro and benol and klotz.

Dann