ASK KEVIN: Do MotoGP Fuel Limits Apply When Riders Switch to Their Rain Bikes During the Race?

HRC fueling a racebike

QUESTION: During this year's MotoGP race at Misano, Italy, the riders were switching bikes as the weather changed from dry to wet and back to dry again. As each entrant is limited to a fixed fuel quantity for every race, what procedures are in place to keep track of the total fuel used among the bikes?

Andrew Shelton

Saint Petersburg, FL

ANSWER: When I asked MotoGP's Tech Director, Mike Webb, this question, he replied that no fuel controls are imposed when there are bike changes such as at Misano. The density of gasoline hydrocarbons varies over a range of some 15 percent, and for each drop in temperature of 1 degree C, a liter of liquid hydrocarbon shrinks by 1cc (which is why there was a controversy a couple of years ago over measuring fuel temperature—one or more teams were stratifying their fuel load, first pouring in very cold fuel, then using a fill plate to spread warmer fuel on top of it, finally insisting that the person with the thermometer not poke it down into the bottom of the tank "for fear of damaging the fuel pump"). I used to raid motel ice machines to refrigerate the fuel I put into my 1970s 500cc and 750cc Kawasaki two-stroke racers.

Thus, it makes best sense to measure fuel weight. Imagine telling the spectators to just sit tight while teams of people with certified scales and beakers of all the varieties of fuel weigh tanks with fuel in them, then drain them and weigh again, etc. while it’s raining.

The only power limits in MotoGP are engine displacement and fuel quantity. Webb would prefer something more easily measured such as a rev limit, but that is a political problem with Honda.

The 20-liter MotoGP allowance does not represent much saving of fuel, as it translates to 5.28 gallons for the usual race distance of 72.5 miles, or just under 14 miles per gallon. That is the mileage we used to get with two-stroke race bikes at Daytona.

More relevantly, the several Boeing 747 freighters used to move the MotoGP show to Australia, Japan, the US, Malaysia and the like each burn 25,000 pounds of Jet-A per hour.

Send your “Ask Kevin” questions to We cannot guarantee a reply to every inquiry.