Yes rolling resistance is a factor. I'm guessing that with a truck it may be a little less important because aerodynamic drag is the largest factor and trucks are relatively not aerodynamic. Especially lifted, leveled and with wide tires. Inertia is huge around town because you have to accelerate but you gen no coasting or regeneration. Each tire/wheel on my truck (stock) weigh over 100 lb.

 

seems this thread as interesting about ultimate fuel milage.
Italian about a debate on wheel adapters.

 

Good to know about Shell,Exxon & B P. I wonder how the Wal-Mart brand ranks? Probably @ the bottom.

 

I recently took my first road trip with the Family to Florida to look for a place to live and a job. I've never did a road trip where I had to do the driving. It was awesome. I have a 2011 f150 supercab with the 6 cylinder twin turbo ecoboost. I was worried about the gas mileage, and I worried for nothing. I got really great mileage I thought. I probably didn't spend 250 to 300 hundred dollars on gas total for the whole trip. And that's with the plugs needing changed. My check engine light is on. I kicked it down once to pass a truck and it hesitated and sputtered badly. And I get a rough idle at low rpms. But I had a code machine put on it and it days misfire or something. Anyway they said it needs plugs. Just turned over 80.000.

 

Here's my experience to date: 2.7 EB, 4x4, XL, FX4, 3.73 locker, SCab. Right now I'm sitting on a solid 24mpg combined. When I first got the truck, I was holding 23 mpg. Then the temps dropped and the switch to the winter blend and I literally watched the mileage drop to 21 combined. It pretty much held steady at 21 over the winter. After the last oil change, now about 365 miles ago, I have been holding steady at 24 combined. I have found that the most efficient speed seems to be about 59 mph. I drive east/west to work and find with the prevailing winds, going home into a headwind, 57 is the most efficient speed (or slower on really windy days).


Still running the stock 265/75R17 Fortitudes, removed the air dam for snow/off road and added a Tonneau cover. To say that I'm both really impressed and pleased is an understatement!


Oh yeah, I didn't take the picture while I was driving......

 

 

 

Just did 620 miles at 75 mph, TN to LA. 17 SCREW, 3.5 eb, 3.55 gear, 4x4 and 19.2 hand calculated, only 2700 miles on the truck. A lot disappointed in the MPG, they Claim 23 mpg. First vehicle I have ever owned so far under its rated mpg. Love the truck though.

I would expect to loose 1 or maybe 2 max at 5 over the speed limit. I think I would have to drive 60 mph to get 22 or 23.

My stingray has a claimed mpg of 29 Hwy, and I get 30.6 mpg at 80 mph.

 

One thing to remember when discussing fuel economy is understanding the effects of winds. Coming from the aviation community I think I have a descent understanding of winds flying for the last decade plus some. First let me apologize because I'm typing this response on my iPhone.

Two different types of speeds we will discuss are ground speed and air speed. I think the definition is on the word so I won't explain them or insult anyone's intelligence...nevertheless, what's important in fuel economy is understanding not just what your vehicles ground speed is but more importantly what your airspeed is. For example, if you're going 65mph ground speed which is what your speedometer reads, but you have a 20 mph headwind you will get the fuel economy similar to what you would traveling at 85mph ground speed. In highway driving aerodynamics play a larger part than anything else.

One last factor in this discussion is predominant or prevailing winds. What I'm about to tell you is not always true but is a rule of thumb that is generally true. The prevailing winds flow from west to east, so anytime you're going cross country to the east you should see better fuel economy numbers than when you're traveling to the west. Rant complete, and I will now go back to bed. Goodnight.

 

The claimed 23mpg is with a 4x2 standard cab XL with 3.31 gears....

Your stingray is a heck of a lot more aerodynamic...and the "tested" model's a lot closer to what you're actually driving.