Hello. I know the manual says 89 octane and can run off 87 while not towing. However I am moving to Denver, Colorado where the octanes are 85, 87, and 91. I am aware of the theory that lesser octane at higher altitudes is sufficient. Does everyone at higher altitudes run 87??? Thanks.

Also, I was thinking I could possibly purchase a programmer to adjust the octane and therefore properly adjust the timing for the higher altitude octanes.

Run 91 oct. For a few bucks more a tank its worth it.

I have never run anything but 87 octane. Including several trips towing through the mountains.

I live in wyoming at 5280feet above sea level and run 87. Never had a problem.

I would go with the 91 ur going to get a little more power outta it and get a few more mpg also, but then again u pay $ diff. for it so u break about even on ever day driving

Mystro and Mi11Z.....I gotta respectfully disagree with your recommendation to run 91 octate. The 5.7 Hemi was not engineered to run with premium gas, which, believe it or not, has a slower "burn" than 87 or 89 octane. To do so is a waste of money. as you'll never make up the difference in cost. And despite what "the seat of your pants" tells you, the HEMI will not run any better.

Guitartate....I'd run 87 octane. Just listen for any sustained engine knock. If there is none, you're in great shape. I've owned two Hemi Rams...an '03 and an '07. I've consistently run 87 octane in both of them with absolutely no problems.

Thanks for the input everyone. I am heading to Denver tomorrow. Perhaps my next venture will be getting some all terrain tires for some mountain roads!!!!

87 octane runs like a sick pig in my truck ( calgary albetra canada ) I tow into BC. on the trans Canada with a gose neck full of cribbing forms with my 2500 hemi. The higer octane is supposed to have a lower burn rate which means the engine has to fire less to get the same power out of a lower octane, go to high and I think you leen out the engine if the timming or tunning is not set for the higher octane.

92 is a rocket, Chevron in BC has a 95 octane, and I tried it ( paid for it $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$) twice the rocket potential but it was fun while it lasted.