Octane booster Help or hurt Fuel Economy?

[Domman56]

Has anyone done any actual A-B-A testing on this? I know since i advanced my timing and stepped Tank up to 91 octane about a year ago i pull an extra 1.5-2 MPG but I'm thinking if this works then some octane boosters may make a difference as well Either good or bad. Anyone on here tried octane booster to boos fuel economy? If not would anyone mind doin it to see if it changes anything?

[Allch Chcar]

Nay, the octane boosters add 1/10th of an Octane aka a point. And the size is negligible to a fuel tank with several gallons. Some of the Street/Racers use Xylene to boost octane. But it is much more expensive than gasoline. Older engines have carbon buildup so switching to a higher octane will help with aging problems but the only way to fix it is to get the engine cleaned, the most common method is to use something like seafoam.

Advancing the timing and moving up on octane has been done before. The benefits are a wash, it can give better MPG but rarely does it compensate for the higher cost. If it does increase MPG Your Mileage will Vary and it differs based on the engine.

[Domman56]

Well i seafoamed it and that definately cleaned out a bunch of junk in the car but I know for sure my car runs smoother and more economical on the 91 octane But are you saying you've used octane booster to try and gain mileage?

[Allch Chcar]

No.

It's a matter of volume. 16 ounces of octane booster isn't going to make an appreciable difference to a 15 gallon tank of 87 Octane. You need more than a gallon of 100 octane to make any difference in that much fuel.