Fuel Tips: Why Not Methanol?

Sponsored article presented by Sunoco.

Running methanol as a fuel sounds great–even more performance potential at a lower price. But, first, some considerations:

Methanol is the simplest form of alcohol. “Methanol and ethanol are commodities and used in massive amounts in the chemical industry,” explains Zachary Santner, technical specialist with Sunoco Race Fuels. “We do allow our dealers to sell methanol under the Sunoco brand as long as it meets minimum quality specs. The source can be from various feed-stocks.” Methanol will kill you dead if consumed, though.
We found an online dealer offering a 5-gallon pail of Sunoco-branded methanol for $48; they get $89 for the same quantity of Sunoco E85-R, a race fuel that contains 85% ethanol. But while methanol costs less than race fuel, Santner adds, racers will use a lot more of it, negating the advantage.
“Methanol has an even higher octane rating than ethanol, but it is difficult to assign an Anti-Knock Index,” Santner continues. In the simplest of terms, the scale used for octane ratings doesn’t easily transfer to high-alcohol fuels.
Sunoco 260 GT, a popular race fuel, has a stoichiometric air/fuel ratio of 14.1:1. The ideal air/fuel ratio for E85-R is 9.8:1. Methanol is happiest around 6.5:1. “This ratio is mass air/mass fuel,” Santner explains. “If we take the inverse of these ratios, we can have mass of fuel needed per mass of air brought into engine. Methanol would be 0.15 while 260 GT is 0.07, meaning roughly half as much fuel mass is needed. Since twice as much mass of methanol is being evaporated in the intake, there will be even more cooling in the intake, leading to a denser air/fuel mixture.”
While methanol is popular in some forms of motorsports, sports car racing isn’t always on that list. The fact that methanol burns clear can be an issue. Many sanctioning bodies either specifically ban it or don’t list it under their approved fuels.