I read a couple threads about the use of 87 in Hemis over on DodgeForum,and people were talking about engine damage (even warned by the dealer in a couple cases) as a result of using 87. Most folks over there are running 89 all the time,or higher if they have a custom tune.

I had always understood that 87 was acceptable,but my truck hasn't been running very strong (particularly weak,off and on),and I switched to 89 last fillup. The difference in power and mileage is apparent. Now,I had tried switching before,I don't remember such a difference then. But in my mind,to prevent damage and to improve driveability,I think I'm going to stay with 89,and maybe find gas that has no ethanol,if possible.

I've read and always been told to never use below 89 in the Hemi motor, so I never have. I use 89 most of the time and throw in some 91 to clean it up every couple of tanks.

I didnt get an owners manuel when I bought my truck.When I filled it I used 87. Im down about a half a tsnk. Does the manuel call for 89?

My Hemi is an '04 and my owners manual says that I can use 87 octane but they recommend 89. I used 87 for a while and then changed over to the 89 and noticed better performance right away.

I do remember that my '03 did NOT say that I could use 87, only 89.

Anybody with an 05 tell me what the owners manuel says?

The only time I used anything above 87 in my 04 was before going to the track. I've tried all three grades and can tell very little difference. There is more difference in brands of gas than grades to me.

I run 93 octane with the Superchips 91 tune.

quote:

I didnt get an owners manuel when I bought my truck.

You can download a pdf version of the owner's manual for free here:

http://www.dodge.com/en/owners/manuals/index.html

Thanks man

We only have 85,87 or 91 Octane here in UT and in MT

I use 90 since that is the highest I can get here in Alaska!

I always used 89 until last spring (2008) when gas was super expensive and I was driving the truck 150 miles a day to get to and from work.

I switched to 87 expeceting my fuel economy to go down, but I kept track to see if it decreased enough to make it not financially worth saving 10 cents per gallon.

My fuel economy actually went up almost a full 1mpg.

Over the last 18 months on the highway I can pretty consitantly get the higher mpg on the highway with 87.

But now that I started driving a shorter distance to work in a little more stop and go traffic the fuel economy seems to have dropped.

So it may be time for me to go back to 89.

I have always used 87 in both my 04 and now in my 07. Never have had a problem. Have tried higher octane a couple of times and could not tell the difference.

quote:

Originally posted by Shifterbrains:
I had always understood that 87 was acceptable,but my truck hasn't been running very strong (particularly weak,off and on),and I switched to 89 last fillup. The difference in power and mileage is apparent. Now,I had tried switching before,I don't remember such a difference then. But in my mind,to prevent damage and to improve driveability,I think I'm going to stay with 89,and maybe find gas that has no ethanol,if possible.

I've always ran 87. Maybe I'll try 89 for a while. Just to clean things up.

I have a question. What is the possible engine damage that can occure by using 87 octane?

I beleve it just makes your knock sensor just work overtime and wear out sooner but i am not 100% on that