Well i have had my 04 Durango since April, put about 11k miles on it and ONLY have put 89 octane and even a few tanks of 93.

A few people have old me that you can put in regular gas, however these are not Hemi people, but are mechanics and car people.

Anyone done this with the Hemi? Any ill effects?

thanks for the info

 

I use a combo of 87 and 89, depending where I am. Mostly its 87. I've had mine since January with no ill effects.
The thing about the Hemi heads is they are dual plug, you'll get a complete burn, even with the lower octane. I don't know what the C/R is on our motors, but I imagine it's reasonably low.

Just my 2 cents.

 

Octane in gasoline determines how the fuel will burn. 93 Octane will tend detonate faster while 87 or 85.5 in high elevations will detonate much slower. I had a 5.9L and burned 87 forever until I moved to Wyoming. Wyoming as well as most of the western US burns 85.5 in the higher elevations and because of high gas prices I was running the 85.5. The 85.5 ran fine unless you wanted to accelerate or pull a grade because the engine was knocking so bad. I ended up going to the dealer and having them re-flash the computer to burn a lower octane to eliminate the knock. Octane is important to a particular engine because that is how the timing of the engine is setup. The Hemi is setup for a slightly faster detonation of the gasoline requiring 89 octane. Conversely 93 detonates too fast which doesn't help the performance. Most people will agree, run the recommended octane for optimum performance under stock conditions.

 

i hav almost 9 grand on my hemi. i usually run the 89 oct gas in phoenix at about 1100 ft.i hav run the 87 in both the heat of summer and the cooler air. when the air is cool and dense i may notcie a difference in pickup but that may be in the head. the motor runst the same no pre det. and i have noticed a 2 tenths of a mile per gallon less with the 87.2/10 of a mile less over 27 gallons equils 5.4 miles a tank less. . the2 dollars and 70 cents saved seem to outweigh the 5 and a half miles lost. all said i still use the 89. on the flip side i notice no mpg extra when useing the highest octane over the 89.

 

I have 9000 miles on my 04 limited hemi and have only burned 87 octane regular with no problems at all-that's what the dealer told me to use in it-regular gas.I live in Jax Fla.I haven't ever noticed any knocking or pinging when climbing any bridge inclines-(steepest thing around here),and i get 23 mpg highway at 75 mph.