The manual states:With recent experience, can I use 87 octane without harm to my engine?

 

89 is recommended for the best performance but 87 should be OK as long as it is not of poor quality and causes spark knock as stated in the manual. See below.

Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required. Poor quality gasoline can cause problems such
as hard starting, stalling, and hesitations. If you experience
these symptoms, try another brand of gasoline
before considering service for the vehicle.

 

So rather than start another one of these threads, I'll just bring this one back from the dead!

Over the first month and 1500 miles on this new Charger R/T, I am convinced that 89 octane gas from my local 76 station makes this car a lot happier than the 87 octane. I've ran couple tanks of each, running the last tank of 87 so low that I was worried about making it back to the station. Filled up with 89, and later that day it was like a switch was flipped.

Engine sound (from under the hood, not the exhaust) is a lot smoother, and the response at the pedal is noticeably better, too. Honestly, I wasn't happy at the idea of spending another .12/gal on fuel (couple bucks per tank); but almost every time I drive the car there's a time when I say to myself "definitely worth a buck" as I poke my foot at the gas pedal.

I know money is tight these days. But if you're running a stock Hemi, try a tank or 2 of mid-grade gas. Sure, the car can detune to safely run 87 - but run 89 for a while; you and your Hemi might just like it as much as we do.