Originally Posted by MelvinSeet

I think both are the same....
My hyper21 onli lasted me abt 3 gallon and there it goes.... loss of power... but still runable....

28. Size is more for Monster... Truggy can also use that... but prefer to be 21.size for my truggy also....

You will change your engine one day also...
Just start off with something cheap and test what you like....