I am a grumpy old grouch....but one that knows 22- 24 mpg in any Hemi truck. unless coasting down hill constantly, just isn't going to happen, especially at 5000+ft altitude. Some of these claims are just outlandish

 

higher altitudes produce better gas milage. I have a '9 CCSB 2WD 3:21 gears and when driving to my mountain cabin 330 miles each way I can get up to 21 MPG on the long flat stretches of the San Juaquin Valley with the cruise control set at 75 MPH. If I set it to 65 MPH, it gets up to 22. Much of it depends on the wind and how long MDS stays on. Last year we took long drive to and around Colorado with high altitude driving in Utah, Colorado and New Mexico. Up at altitudes, the MPGs were even better. I've noticed that phenomenon before on other trips with different trucks I've owned. If you don't believe me just google high altitude driving.

 

I am at 7000 feet, we call the folks in Denver flat landers.

 

Pedro Dog is quite correct here in reference to high altitude producing better mileage - NOT worse: "When an engine requires lower levels of octane to “fire,” the overall efficiency of the engine is also lowered, which means the engine works harder to achieve the same results. However, less fuel burns, which means the overall fuel-per-mile efficiency is increased because the engine is working at a reduced compression rate. The air is thinner and the vehicle slices through it more easily as well - less drag. In short, you can get higher miles-per-gallon at higher elevations, but the power of the engine is also somewhat reduced."

Most folks report up to 6MPG better up here then at sea level. Just because you don't get the same mileage as I do does not mean you operated under the same conditions. In fact, because of my altitude, I can use 91 octane with a 93 tune no problem.

 

You guys aren't going to get 22-24 mpg average. Anyone can make the lie-o-meter read those figures temporarily, but see what it says after a whole tank, and then calculate manually. Rom....I have used a 93 tune on 87 octane here in Tennessee, and no knocks at all. It depends on what your anti-knock sensors are doing, as far as retarding ignition. My old trucks knock sensors retarded 15 degrees at WOT, and I probably could have run it on kerosene if I had wanted to. I can see some of your reasoning but what you gain on flat land or descents, will be basically negated by those uphill pulls when your engine is gasping for air and making poor power. An engine under strain, gets very poor mileage, and at 7000 ft you're going to strain a lot when you go UP those mountains

 

Pedro, anybody can get good mileage on flat surfaces cruising at 65 mph, but your average mpg includes every kind of road you drive for a full tank. We aren't talking about temporary mpg in this post but average mpg. The two are quite different

 

We've owned our cabin for 23 years. The round trip drive including our local driving is about 700 miles. We go from city driving to mountain passes to valley driving to foothill driving to country driving then repeat in reverse for the drive home. My '09 truck will get 18-19 MPG average for the whole trip. On the valley stretch (about 190 miles), it will get 20 to 21 MPG at 75 MPH. I'm not making this up.

On last years trip to colorado, I set the odometer and left the EVIC alone for the 2,300 mile trip. The truck was set up for a 10 day camping trip. Had the camper shell on with about 300 lbs of supplies. We drove from San Pedro CA (sea level) , to Williams AZ campground (7,800 ft), to Monument Valley, Utah (5,800 ft), to Cortez, CO to Telluride, CO (around 10,00 ft), to The black Canyon of the Gunisson NP (8,200 ft) and back through, Ouray, CO (11,000 ft pass), Silverton, Co, Farmington, NM, Gallop, NM, Williams, AZ and back home. When we got home my EVIC read 19.5 MPG for the 2,300 mile trip. I tried to go back with the receipts to do the hand calc but some machines did not provide receipts. I did do spot checks and I was getting 18 - 20 MPGs for most of them. besides the speed trap coming into Telluride, it was a great trip.

Not sure why you are so grumpy, must be the bad MPGs

 

To: Old Man with a hemi
Ok, so we`ll use your temporary mpg method for this one, and you arent going to be happy after reading this one either... On the way home tonight from work (37 mile trip one way with some short hills here an there) my "lie-o-meter" went no lower than 29mpg, i reset it tonight before i left work. Sooooo, what does THAT meen, i`m still only getting 12 mpg like some others in here...???... not thinkin so. I`m not trying to piz in your wheaties my friend, i`m just amazed at how people will complain of their mpg when THEY are their own worst enemy. I do everything possible to get the best economy i can, gas is very costly to me for how far i have to drive everyday, i have to find ways to conserve, whether its finding the best tire for mpg or the best lubes, to waxing the piz outta my truck once a month to make it slip thru the air easier. Not to mention, i get it aligned twice a year, which dosent cost me a dime, a friend takes care of it for me for free... i need this truck to roll with the least amount of resistance to obtain great mpg. I cant be without a truck for my job, but on the other hand, i am VERY pleased with getting 22 to 23 mpg out of my hemi truck during the summer. It is what it is... whether you believe others or not. Just because YOU arent gettin great mpg, it dosent meen some others are not.

 

Munch munch munch, sip, BUUURP.
Mmm popcorn.
Munch munch munch.
My cola is low.
Be right back.
Shh.

Hey, down in for front.
Excuse me sir.

Can I get a refill?
Root beer.
Thanks.

Sip.

 

My lie-o- meter has been at 30 mpg before but that doesn't mean I'm averaging over 20 mpg. Maybe your not getting 12 like some people on here but I seriously doubt you are averaging 22-23 just because the meter goes to 29 for a bit