It also depends on what is most popular at the track you race. 1/8 gas is big at the track i race and 4wd electric is a rare occaision to run. I don't mess with nitro so i have a kyosho zx-5 and the lipo packs are suppose to give up to 15-20 min of run time with brushless (from what i read.) It all depends what you are after.