Originally Posted by cdelong

a lot of guy's are using the 2018 pipe and that yeilds real good mileage. i see quite a few 2031 pipes as well. i have never tried the 2031 so i can't comment on that one.

the change from 30% to 25% will not hurt your engine. you may have to lean your engine slightly as there is less nitro (less oxygen), so less fuel is needed for a given set of conditions.