This topic comes up about once a month, and the answers are the same.

The only thing a person should look for is a good brand fuel with genuine 20% oil (blend of castor and some other good quality oil, perhaps turbine oil) and accurate percentage of nitro content. The color is usually a come-on.

So, even though I have recommended a particular brand in the past, I won't this time because I've already done that. What I WILL recommend is that you buy a good quality brand fuel with the recommended percentage of nitro content and at least 20% oil blend. Period. Try it out. If it works out ok, then stick with it. I've tried several different brands and they all have run just fine in ALL my engines, from .40 on up to 1.60 glow and I've ended up with one particular one because it was readily available at my LHS, which may drive most purchases for most RC'ers.

CGr.