Year = 2009
Model = Ram 1500 Reg Cab 4x4
Engine = 5.7 Hemi
Highway percent = 100%
City percent = 0%
Off road percent = 0%
Location = Burnet, TX to Okmulgee, OK 421 miles in 22 gallons. Mostly driven between 65-75 mph.
Octane = 93
Hand or computer calc = Both
Miles on truck = 25000
MPG = hand = 19.1 computer = 19.5
Mods =K&N Air Filter, Flowmaster (not sure what series... came on the truck) and Bully Dog Tuner

 

You should not be running 93 octane in the 5.7 hemi. Manual states 89 max.

 

Depending on how you have a Bully Dog Tuner set you may have to use higher octane fuel in order to prevent engine knock. I used this product on my 2007 Ram 1500 4X4 Laramie 5.7 hemi. It did improve gas mileage average 2-3 mpg and had a moderately noticeable improvement in takeoff power set on economy tune. I only set it to high performance one time and I can verify it will cause knock if you do not use higher grade fuel.
Still waiting for the software upgrade before I can put it in my 2012 since I still have it.

 

I set the tuner to premium so my computer is compensation for the higher octane and it runs great. I could tell a prettybig difference in gas mileage between Oklahoma's 91 Oct and Texas' 93. I have never ran a lower octane in my truck than 91 since i have ownwed it. I have a buddy who run 89 gets 3-4 miles less on average than i do but he is a little heavy footed.

 

Ok, so I've been keeping up with my gas receipts pretty religiously, and I've wanted to put it all in a spreadsheet, which I have done. Here are the results:


Total Miles Driven 13019
Total Gallons 906.2
Average Price Per Gallon $3.40
Average MPG 14.4
Average Computer MPG 14.8
Maximum 18.5
Minimum 10.5

That blows goats.

 

Well, I think the high amount of city driving coupled with the 3.55 axle ratio is hurting you. If the majority of your driving is city you probably could benefit from 3.92s, or maybe 4.10 gears would even be better. Whether Chevy or Ram, my big trucks have always done the worst in city-type driving. City driving is the only area my 2003 Dakota 4.7 did better than my current Ram.

Regards,
Dusty

 

So, the next questions are how easy is it to swap out to a different axle ratio and how much better gas mileage can I expect?

 

Never mind. Just called Ram. My truck has a 3.21. Not sure why I thought different.

 

2012 Ram, 5.7 3.56 gears. No mechanical mods except K&N cool air box. Was getting 18-20 MPG (computer) consistently from new. Still less than 4000 miles on truck. Been running 87 octane basically Marathon Shell and Citgo. The other day Bought Exxon, mileage immediately dropped by 1-3 mpg. Both highway and city. I drove gasoline tanker yrs ago, i personally do not believe gas at the pump is different by brand as I have loaded 9000 gals Mobil and dumped 3000 at shell, 3000 at citgo, 2000 at this 2000 at that. I'm sure somewhere along the line, maybe at the refinery there MAY be a difference but not sure of that either. What I DO know is sometimes you have 500 gals of Kerosene, fuel oil or Diesel and load 8500 gals of Gas on top so yes, in essence, there IS a difference in gas. Testing gas mileage on one tank full tells you very little. I will say I'm very happy with the overall mileage I get from my Ram as compared to any Ford I ever owned. And thats MANY!

 

i have a 2012 ram 1500 outdoorsman with the 20" wheels and i get about 17.5MPG highway. my truck only has 1000miles on it. When can i expect this number to go up? my understanding is that its harder on gas at first during the break in period and my gas mileage will improve eventually.