If you aren't a racer and don't need to wring the most power out of your engine the you will get much more engine live by using a high nitro airplane or heli fuel.

Car fuels typically are 12-14% oil but airplane fuels are typically 18+ oil content. I run a 50/50 mixture of 30% nitro heli fuel mixed with a 15% castor blend airplane fuel. This gives me a nice fuel which contains a kiss of castor, 19% oil content, and 22.5 % nitro. The engine loves it and I'm on my fifth gallon and it idles and runs like new.