engine knocking when accelerating

[WRBlue]

Originally Posted by hans_fh

I JUST CALLED THE SALESPERSON TONIGHT, HE TOLD ME UTAH IS ON HIGHER SEA LEVEL SO THAT 85 IS FINE FOR MOST OF CARS. HE IS BS!!! ANYWAY I WILL SWITCH TO 91 AT CHEVRON TOMORROW.

He's right. At higher elevations, an engine needs less octane fuel to prevent knock. It has to do with the lower density. Thats also why you can't compare quartermile times at different elevations.

You're probally getting knock because of the summer heat. Hot air explodes easier than cooler air. Thats why You run richer in the winter and leaner in the summer - but the computer corrects for it. Also thats why carbs need to be retuned every season to run the best.