I use 87 with not problems. I've heard others say they got better mpg with 89, but I haven't tested it.

 

99.9% of my tanks have been mid-grade 89 fuel. Have never noticed a dif when in a pinch (ie: driving in the Canadian country side) and had to run 87. I always buy the cheapest gas, as long as it is 89 octane. 36,000 miles without one single knock...ever.

 

the never development of the 4 cylinder shutdown by dodge is on the new Hemi Trucks/Cars .. shuts down 4 cylinders when the computer does not think that the 8 cylinders are all needed .. saves on gas they say ... you should read more into it, pretty interesting ideas

 

this is a 3 year old thread dude