[TexasJester]

While on a cross country trip this week I decided to run different octane fuels just to see if there was any noticeable difference. If at all possible I use Exxon fuel and especially on this trip. I used 87, 89 and 93 octane. I noticed absolutely no difference in how it sounded, felt no difference in how it ran. Here is the part of this that really shocked me. After running a tank of 93 until the gas light came on, then ran a tank of 89 til the light came on, then a tank of 87. The tank of 87 octane I got 20.1 mpg! I have not been able to hit 20 again but was shocked it did that and with 87 octane. I get a consistent 15 mixed driving and the only other long trip I’ve taken it on it did 17.2-17.5 consistently. What are you guys seeing out of yours?

 

[iTommy]

are you sure there's no long term damage to the hemi engine if you keep using the 87 octane?

 

[Krampus Wagon]

I honestly don't track it close,but I always use 93.

 

[TexasJester]

I don’t either but I was off on a long road trip and bored! But believe it or not I actually got better mileage on lower octane.

 

[Krampus Wagon]

I don’t either but I was off on a long road trip and bored! But believe it or not I actually got better mileage on lower octane.

Wild...wonder if it had to do with elevation?

I'm sure running 87 is fine, there are waaaay too many 6.4s on the road and to imagine everyone is running 93 is a pipe dream.

I'd be curious performance wise of differences...either way it is probably miniscule.

Part of me also wonders if what you're getting out of the pump is what they say it is.