i heard from somewhere that you are suppose to run premium fuel in these trucks. mines a 2004 2500 5.7 hemi. wat happens if you run 87? this is a stock truck, thanks!

 

The owners manual claims that 87 octane is OK, but for maximum performance use 89.

HOWEVER, everyone I've ever known to blow a cylinder/piston/etc. on a Hemi engine has admitted or been very suspect of running 87 octane fuel over long periods.

So, burn 87 at your own risk...

 

yea talk to redone. he used 87 for not even a whole summer and got a blown piston...

 

In Colorado we have 85 (low grade), 87 (mid grade) and 91 (premium). I've always been told (right or wrong) that due the altitude 85 was equivalent of 87 in the flat lands and that 87 was the equivalent of 89 and so on.....

So would you run the mid grade 87 or premium 91. 89 Octane is not an option I have found.

 

Here we go again...look here.

 

What a concept! Who'da thunk it? Mine says 91 recommended, 89 acceptable, 87 only if no other is available. 93 not recommended. I mix 87 and 93 to get somewhere in the 90 range.

 

I guarantee your owner's manual (03-05 in your sig pic?) does NOT say 91 recommended. If you're running a programmer, then that's a different story.

 

Ive ran 87 octane since i got the truck 60,000km now never a problem and i run her hard....tried 89 octane the other day at half a tank now noticed ZERO diff in anything maybe if i ran a my tuner at 91 octane and used 91 it would run better but i notice 0 diff between 87 and 89 just the money in my pocket....prob runs cleaner in the motor tho.

 

^ thats bc you have a programmer set on the 87 tune. people that dont have a programmer dont need to be running 87...

 

My manual for my 05 says 89 recommended 87 ok. You won't be able to put a half a tank of 89 in and tell a difference but over a long period of time you will come out better. The engine will run cleaner and with that run better and you ain't talking but a buck or 2 difference on a fill up. Now if you are running a tuner you should run what ever Octane is recommended for the tune you are running.