Originally Posted By: Clevy
Pure gas has more btu's than e10 however if your car will advance timing til it senses knock then the e10 will give a very slight performance boost.
Yes e10 is oxygenated however that oxygen displaces fuel in each drop,so I use pure gas whenever possible.
Here our premium is pure gas and the regular is e10,so I run premium in everything.
I don't think "displacing fuel" matters as long as more fuel can be injected into the combustion chamber.
I've seen some stuff from racing gas marketers about how a lower octane fuel with a higher oxygen content actually produced more peak power than a higher octane fuel with less oxygen. However, they had to increase the size of the fuel jets in order to get more power. Getting more fuel in the combustion chamber actually isn't as hard as getting more air (i.e. atmospheric oxygen) in. The basic idea is that more oxygen in the combustion chamber in the form of alcohol or MTBE is similar to getting more oxygen in from the atmosphere. We all know how to get more air in - more valve surface area and forced induction. But then there needs to be more fuel, and it's not all that complicated to get more fuel in there to match the amount of oxygen.
Quote:
http://www.circletrack.com/enginetech/ctrp_1212_oxygenated_racing_fuels_new_fuel/
VP's Freddy Turza explains that oxygenated fuels are most effective in stock-style or low compression engines because the oxygenated fuel blend helps the engine work more efficiently. "A lot of times when people hear 'oxygenated fuel' they think about cheating with nitromethane in the fuel. And that's not the case. There is a power-enhancing chemical blend that goes into the fuel but the purpose of it is to achieve better vaporization to equalize all of the runners in the intake manifold.
"Whenever you have to work with an inefficient combustion chamber, that's where this fuel is typically going to be the most helpful," he continues. "Like the CHP fuel we designed specifically for applications racing crate engines like the Chevrolet 602 or 604 engines. Those are typically lower compression engines and its efficiency is low because of restrictions in the carburetor, intake manifold, or the intake runners themselves. By increasing the efficiency of the fuel, you are able to help these types of engines generate more power."
Some racing engines use methanol. They simply squirt a higher volume of fuel into the combustion chamber.