My truck only gets 12 mpg running 93 octane. lol Price to pay for 300+ HP I suppose.

 

When I first got my current Blazer it had a 3" body lift and 31" tires and was getting about 12 mpg on 93 octane. I had a spare ecm with the stock chip that
I replaced the other one with and I went
back to stock tires and now get about 17
mpg.

 

My truck would look funny with stock tires... lol

 

Myth: Putting premium fuel in your vehicle, even when it doesn't require it, will give your gas mileage a boost.

It may seem like premium fuel equates to better fuel economy, but you won't see even the tiniest jump in your mpg by using premium fuel in a vehicle that's designed for regular.

In fact, it's just a waste of money, Molla says. Premium will cost you about 15 to 20 cents more per gallon, which can add up to $100 or more per year over time, according to the Federal Trade Commission.

In addition, "Using a higher-octane fuel than is recommended will have no effect on performance or fuel economy," Molla says.

How to save: The FTC says that unless it's recommended by your owners manual, don't spend money on higher-octane gas.



Read more: 6 Busted Fuel-Economy Myths To Save On Gas | Bankrate.com
Follow us: @Bankrate on Twitter | Bankrate on Facebook