Wanted to share a gas mileage thought. We are all trying to increase our mpg...here's something I ran into. I live in Northern Illinois AKA "the corn belt" and we have had 10% ethanol in our gas around here for many years. I recently drove out to North Carolina, probably 90% interstate (70-75mph). As soon as I got down south and away from the stations selling the 10% ethanol blends, my mileage shot up about 3mpg. At one point I was at 20mpg. On my return trip, it dropped as soon as the ethanol stations reappearred. My 06 1500 Quad 4x4 5.7 Hemi (all stock) had about 6000 miles on it at the time. So you guys that have the advantage of burning 100% without the wonders of ethanol blends, enjoy it. I am now back to my 15-16 mpg, depending on my driving. This may explain why some of us get worse mileage than others.

 

Yep. That's the trade off. Fuel that's supposed to be a little cheaper and also supposed to be environmentaly friendlier for mileage....
I put E85 in my Avalanche a few years back. Couldn't wait to get back to the regular stuff which with the reduced mileage, it didn't take long.

 

My same observation while driving out west. Cost wise it is probably better to go with high test or even regular. On ethanol mine gets around 14. On regular, 16. On mid-grade non-ethanol, 17+. Maybe a little more environmentaly friendly but definitely not on the wallet.

 

Makes sense to me....cheaper fuel with less MPG, now see how that works. Out here in West Texas I only run Shell 89 octane and I get about 17-18 in town and can actually get about 20-21 on the highway, now consider I'll run the cruise set at 66 mph on predominantely flat roads in 90 degree heat, I consider it good. I've tried Chevron, and a few others but seem to get my best out of the Shell fuel. I think it really has to do with it being such a busy station, and they get fuel refilled sometimes twice a week & that it might be better gas...who knows but I've calculated five full tanks now and come out with the same manual configurations. Don't rely on the overhead it is nowhere near correct, some of you may actually be getting better than you think without even knowing if your relying on it fo figures. I also keep my tires rotated and oil changed every 4K for good measure, and of course it helps to ease off that accelerator at the stoplights and take it easy, although it's hard to do!

 

OOPS ....I forgot I'm running a 4.7 in an 06 quad cab with the 20's

 

i tell ya'll if you cant keep your foot off the accelerator a 4.7 in a single cab truck can suck some gas. i usually get about 14 mpg becuase of my foot but when i drive good, which doesnt happen often, i can get it up to 18 mpg in the city.

 

Forgot to mention...we are paying the exact same price per gallon. This 10% blend is not to be confused with the E85, which does sell for about 20 cents cheaper. They just add this 10% because they claim it burns cleaner. My point is, just this 10% (which is 100% dominant throughout,) robs us of better mileage. So as I browse the forum and one claims to be getting great mileage while another claims crappy mileage...this could be our culprit. If you have a choice, stay the hell away from the 10% blend.

 

In Connecticut, the 10% ethanol is by law. They were using something called MTBE at 10% but found it leaches into water supplies and causes cancer. Oops. It used to only be in the winter but now is year-round. I believe Mass. also has the same law. My wife thinks that gas we got from trips to NJ and VT got better mileage in our minivan. I wonder if they sell pure gas in those states in the summer.

 

One other reason I will not use ethanol in my car (other then the loss of 2-4 mpg ) is that about every 1500 miles I have to run injector cleaner in the fuel to clean out the junk that always cloggs them up.

FYI, I have had this happen in several of my cars, including a 2005 Dodge 4x4, 4.7L. I had one car run 10% ethanol for over 12,000 miles and it would still get clogged injectors. I do know of one car a 1990 Dodge 4 Cly. that got the same mpg no matter what kind of gas you used in it. The only thing I can add is to try it out and see what gives you the best bang for the $$$.

 

I'm the same way....ever since I gtot my Flowmasters a couple years ago, I constantly drive like a jackass, but I'm only getting about 11-12 MPG in the city in my 4.7