Whoops, I didn't mean to link the same one twice. My bad.
Anyhow, simple phrases work best. For instance, if fuel mileage doesn't net you a response (for one thing, it's redundant. Mileage is typically a measurement of fuel consumption over a set distance, ie. one mile) then you rephrase it. In this case, I searched for "mileage". If you wanted to utilize the word 'fuel', then 'fuel economy' would have been better.
Then you can just scan through the thread titles and highlighted words to see what might interest you. If you get too many results, then you can narrow it down by seeing what tends to come up as a result to choose new keywords.
Hope this helps you with the MA search function. Good riding!