Last Wednesday I went to the Washougal MX track for some practice and picked up a can of VP Ultimate 4 race gas, after reading a favorable write up in a mag some months ago. I drained my tank so as to be sure I was only running the VP. The results where impressive, there was a definate difference in the power delivery. The bike pulled harder off the bottom into the top end. Running pump gas later in the day really showed me the difference. Highly recommend this for racing, but at nearly $10 a gallon not for trail riding.