my brothers friend is a mechanic at a dodge dealership by me and said not to run 93 (stock) because it makes the engine overheat. which is why i run 87

 

91 here....tuned for 91 octane

 

he's an idiot

 

Wish I had read the damn manual lol I figured higher oct better for the engine... I've been dumpin 5.20 extra in for every fill

 

Never put anything but 87 in it.

 

not exactly. when i had my 08 3.7 w/ 26 gal tank, i drove back and forth to colorado every week. and i had the trip spaced out to have the fewest stop possible. i would run that truck to E and then some. i could make it from tulsa, ok to colby, ks 6.5 to 7 hrs away on one tank. i always always ran that truck as low as i felt comfortable with. and never once got more than 23.5 gal in the tank. plus the difference in fuel grade prices also varies. in co there was a 20 to 30 cent difference so depending on where you are at it may be more or less. iwas just doing basic math

 

I always run 87 - it's so much cheaper than 89, and honestly, I couldn't tell a difference in performance or mileage the few times I tried 89.

I even used E85 one time - I had a 1/2 tank of 87, filled up with E85 and had no problems at all.

 

the manual says to use 89 so i go with that cuz i dont have a programmer

 

When the pistons need replaced from detonation holes burned in them, the .10 a gallon difference isn't so much cheaper. That's only $2.60 a tank if you run it dry for 26 gallons. This is why it is recommended in the owners manual

93 will not hurt anything with the stock tune, it just isn't needed. The timing/fuel trim of the stock tune is designed for 89 octane fuel.

 

He needs to give back his ASE certification

It wont overheat I promise you. Learn what octane rating mean and you will understand why it wont overheat.