I've been running mid grade (I'm at about $30k miles). No issues till recently, we have summer gas in MD and between that and the heat wave, the big D felt SLOW. I ran it down to empty and filled it with premium and noticed a HUGE difference in performance. Smoother acceleration, more power, runs like new.

Anyone else dealt with this?

 

Premium either Hess or Shell
STEVE

 

https://dodgeforum.com/forum/3rd-gen...-in-the-d.html

 

I use 89 from BP and if Im going on a road trip ill use 93 with octane booster.

and from the last time we talked about this last thread there is a difference i dont care what anyone says :-)

 

Yeah well, I bet my $3.31 a gallon 87 Octane running R/T will still kick a rice burners ***!....lol

 

89 octane.

 

I have jumped back and forth from mid grade and premium. I have had the best results IMO is 89-91 octane. In fact my last tank of 93, I got .5 mpg less then the present 89.

 

My 6-banger Crew runs fine on 87 octane Exxon.

 

What kind of Mileage you guys getting with Your R/T's down there in the U.S.A
were you have real gas.

We just returned from a trip almost 2000 miles and averaged 25 mpg (UK gallons)
with a 2012 R/T-5.7 hemi.


Napper505

 

I found this in a similar thread when I did a search

RTFM. Pg 511,*Fuel*Requirements 5.7l Engine:*"The manufacturer recommends the use of 89 octane for optimum performance. The use of premium gasoline is not recommended, as it will not provide any benefit over regular gasoline in these engines." Gotrpm posted it