I don't remember the exact numbers, but I posted it on a forum somewhere. I know it wasn't this one because I hadn't discovered this forum yet. I mainly only used the truck to go back & forth to work, same route and tried to drive the speed limit every time. I remember after figuring in the price difference and mileage, etc., it was darn close, but it was costing me like2 cents a mile more to run the economy tune with 87 octane gas than the performance tune with premium gas, so for the extra umph and better mileage besides, it was a no brainer.
If I remember correctly, I was getting just shy of 2 mpg better with the perf. tune and after figuring in the twenty cents per gallon difference it was costing me like 22.1 cents per mile with the economy and 20.3 cents with the performance. I'm thinking I was paying about $2.50 a gallon for 87 and $2.70 for premium at the time, so obviosly the cost per mile for each would be up considerably more now...

 

Best setting for power I liked setting it to the 87 econo tune and running 89 octane, ran great but the mileage was only getting me a little over 12 city/15 hwy, Im running the 91 tune now on 91 octane and I'm getting 15 city and 18hwy and Im not driving with a light foot either so I still have get to have fun at the same time. Sure the extra for the premium sucks but filling up every other week for $70 vs filling up once a week for $65 is worth it to me.

 

Where the hell are u filling up for 75? It takes me damn neer $100 to fill up. It also depends where i get my gas at. i have no idea why but it does. And ive tested it with 2 tanks from each place. And if i fill up at costco vs chevron i get 1.7-2.0 mpg more just from filling up at costco. So i dunno ill run the test on both setting and ill let you guys know

 

I should have mentioned I'm in Canada so 91 octane for me is about 42 cents a gallons more than 87 octane. On my '98 the cost per mile was just a tad higher running performance setting. I haven't tried it on the Hemi, but I'm thinking if guys are seeing 2-3 miles per gallon increase in mileage, it might be worth checking out.

EDIT: Well I just ran some numbers and even 1 mpg increasein town at 42 cents more per gallon I would break even if not a little better on the performance setting. So I guess the next fill up will be premium and a program change and thensee how I like it.

 

Yeah ramdamit im gonna be doing the same

 

So i tuned it today and wow, big difference. I seen some people had issues with the whole MDS kickin in and out. Havent had that yet and i drove 30 miles to work and 30 miles back. But wow does the Flashpaq add some power. One thing though is i measured my tires and even though they are "35's" they measure from top to bottom 34.25 so i set my tire size to that and i can get going 90-100 no problem it seems like. It doesnt seem like im going that fast though. Im gonna have my friend speed match me in his stock truck to make sure my speedo is reading right. And this is only on 87 octane setting i cant wait till the next gas up and change it to 91 Perf. This hemi suprises me with every little mod u do to it. my buddy has a 06 chevy and he has done alot of same mods ive done and the power increase isnt anywhere close to my gains. Hes jealous haha

 

IMO the stock Hemi has as much or more untapped HP potential than any other current gas engine on the market. They really had to tone the sob down a good bit for emissions. If we say screw CARB complience and F**K the ozone layer, we can really get some performance outta it...

 

Yeah i live in Cali to, by far the worst for emissions. But whatever. Ill take it to another state and register it if i have to. And that stupid In cab MPG readout is a lying bastard. Ive added CAI, Exhaust, Superchip, and even changed the oil to sythetic (royal purple) and that thing still doesnt go up. Lol so what the hell why add something that isnt accurate.