I have been racing nitro for close to 14 years now. I have used all of the fuels, Byrons, Sidewinder, VP, Rocket Science, Omega, Dynamite, etc. In my time I have had some bad batches of fuel but all I suffered was random flameouts or just no way of getting a motor to tune. I have never to the day had a rear bearing go out. Not trying to sound like a wise guy but I guess I am just lucky. I have been using VP for about 2 years now and have not had any issues. I have an OS thats on 12-13 gallons as we speak and still kicking. Still has the original rear bearing, replaced the front once due to leakage.