I've run the 89 octane in my 5.7 hemi as recommended in the manual. Just curious to know if anyone has run lower or higher grades and if they noticed any difference?

 

I have run 87 since day one, I have not seen any adverse effects. I know many will disagree with me though.

 

bump

 

I used 87 at one time, 89 only now, although I don't notice a difference.

 

I have never put anything but 87 in my truck and i have never had a problem it has always ran great.

 

i only run 89 shell gas in my 06 hemi

 

I've ran 87 and noticed a very slight decrease in acceleration when passing on the freeway.

 

I ran 87 in mine maybe 2 times unil I heard some horror stories in this forum. U might wanna do some research.

 

87 octane, my truck runs like a sick ford, 89 octane my truck runs like a hemi, 92 octane, my truck runs like a rocket and mileage is best with 92. I don't have a tunner, truck is stock accept for the dual EX.

I do think altatude has a influence on octane and performance.. I found a service station here in Calgary Alberta were I can get 92 octane for 81 cents a liter or less, so I use the higher octane, I can get 800 km to tank mixed city high way with granma driving and 92 octane.

Gas plus
6813 ogden road SE
calgary ....

 

There's really no point in running any higher than 87 unless you get knocking, then go one grade higher, ect... until the knocking stops.

The FTC (Federal Trade Commission) states:
At the Pump: Use the Octane Level You Need
Your owner’s manual recommends the most effective octane level for your car. For most cars, the recommended gasoline is regular octane. In most cases, using a higher octane gas than the manufacturer recommends offers no benefit. Unless your engine is knocking, buying higher octane gasoline is a waste of money.
http://www.federaltradecommission.com