93 octane worse mpg?

[chevync]

I filled up 2 weeks ago using 93 octane, I only got 270 miles before low fuel light came on. I can run 87 octane and get 340 miles to a tank, I have always thought you get better mpg out of 93??

I tahoe has a rebuilt engine with 1500 miles on it and I also replaced all four oxygen sensors, plugs and wires during the rebuild.

 

[Physh1]

Nope...not unless you're tuned for it. Octane is nothing more than gasoline's resistance to detonation. Your engine is factory tuned to run perfectly fine on 87. 93 really is a waste of money unless you've had it tuned to take advantage of it. Even then...you'll see a little sotp performance boost rather than a mileage increase. Stick with 87.

Cameron