Feiago 9XL VS 10XL
 

I`m thinking about changing from 9XL to 10XL on my crt truggy.
If i gear it harder i wil get the same speed, but wil i get more rune time with an 10xl insted of an 9xl?

What voltage are you running at the moment?

The trick with making feigao motors work at their best is to run that about 35k rpm. This means that the 9xl will do best on 5s lipo and the 10xl best on 6s lipo. If you are already running the 9xl on 5s lipo and are geared for approx 35-40mph you are most likely about as effecient as you will get with a feigao. Going to a 10xl and gearing up to make up for the loss of motor rpm will not be better. I am sure that it will work, but not with any benefit, and may be harder on the esc and batteries.

I`m running with 4s and 9xl, i think this is working well but i whant som more speed.
The car is a jammin crt truggy my gearing is 62\17

Go with an 8xl and gear up a little, maybe a 18 tooth pinion. Or go up to 5s lipo on the 9xl. Either way the truck will be faster.