Strange But True: The Temperature Of Your Fuel

Is cooler gas better?

We’re always looking for ways to sneak extra performance from our rides – from pipes to big bores, from weight shaving to race fuel. But did you know that a very naturally occurring phenomenon is yielding you a little gain (or loss) in horsepower every single time you ride?

We;re talking temperature of your fuel. Believe it or not, when your gasoline is cooler you gain a little performance and when it’s warmer you lose it. Why? Well, we have to go back to our dear pal physics to offer up an explanation.

The process begins with density. The cooler the liquid, the more dense it becomes. The denser the fuel, the more potential energy per given volume compared to the sparer concentration of warmer fluid. Or another way of saying it? You can pack more fuel molecules into that cylinder with cooler liquid.

Next we have chemistry. When fuel temperature increases, so too does carbon monoxide and hydrocarbons. In short, more chemicals that do not benefit combustion performance.

So what kind of gains are we talking here? Nothing earth-shattering. You may gain a horsepower running cool gas that would be felt in the upper reaches of your RPM spread but most of us aren’t coming close to using a fraction of the ponies our machines have on tap as it stands.

Would anyone benefit? Actually, yes. Racers who seek any kind of performance advantage over the competition might want to store their fuel in a cooler place prior to start. The biggest problem is keeping fuel cool. Our vehicles are designed as literal hot boxes – tanks often positioned directly above hot engines and exhaust pipes. Sure, someone could invent a refrigerated gas tank but the added weight and complexity of such a system would never justify the tiny performance gains.

However, don’t for a minute think that in the ultra high stakes, multi-million dollar world of professional racing this little advantage isn’t overlooked. Fuel temperature control device between injectors and the fuel pump to cool down fuel and thermoelectric module chips (TEC) can be applied to absorb or dissipate heat from the fuel in certain cutting-edge performance instances. When it comes to an edge, there is no such thing as too many free ponies.