Inspired by the 16.1 mpg my son reported last weekend from Wilmington to Charlotte, I drove the truck more carefully yesterday from Asheville to Charlotte and got 17.1, per the UltraGauge. To Saturnine's point, I don't know for certain how the UG calculates mpg, so next time I have a good opportunity I'll calculate mpg the old-fashioned way and compare results.

 

Keep in mind that your odometer and thus the reading on the UG for miles per hour and miles traveled are both incorrect. If you want to know your actual mpg you have to do it the old fashioned way AND know the actual distance you traveled by whatever means necessary other than your gauge cluster. In the past I've recreated my trip in a maps application to determine actual miles traveled. In my case with stock tires I was erring on the side of the odometer reading more miles than actual. Now with larger tires it is wrong in the other direction reading less than actual miles traveled. This is why a lot of people think larger tires lead to less fuel economy. I found over the course of a 300 mile trip it was off by around 25 miles which is nearly a 10% error.

 

Larger tires do lead to less fuel economy

"Larger tires are heavier and have more resistance on the road, which can drastically decrease the overall fuel economy of a vehicle. Larger tires may also require larger wheels, which can increase the weight of the vehicle. A driver is expectant to see up to a 10 percent loss in fuel economy when increasing a car's tire size."

Weight is a huge factor as well as poorly inflated tires. Is it possible to get a decent MPG in a Land Rover, No. Simple fact is they weight too much and the aero dynamics are terrible.

Flat roads with no wind can help, getting all the junk out of the trunk also helps. Oddly enough, "Sports Mode" has helped with MPG because the higher rpms in lower gears to get the truck up to speed.

 

I think I got 10 mpg last tank...
Just driving around town...tank lasted like a month

 

Ok, I agree larger tires do lead to lower mpg but they also lead to you thinking its worse than it actually is by having an unfavorable math error in your calculation.

 

 

I realized I didn't need to wait for another trip to calculate mpg the old-fashioned way. We drove a short distance to fill up Redrover's gas tank. It took 8.8 gallons to fill the tank, and according to Google Maps the distance travelled was 150 miles. That calculates to 17.0 mpg. That is very close to the 17.1 mpg reported by the UG. Seems pretty accurate to me. BTW, the tires are stock size 255/65 R16s, and the odometer miles were within one mile of the Google Maps mileage.

 

306 miles ÷ 19.85 gallons = 15.41mpg.

Slight down tick, but traffic has been maddening of late (it's a bit*h when everyone is working again...boy...how l yearn for the 2008/2016 years...lol)...and l'm seeing a bit more idle time at lights.

Brian.

 

Doing a bit of a fuel study...

Switched back to BP mid-grade 89 octane on Sunday...and mileage dropped off...14.3 mpg again (which, most of this tank was coming home from up north, rarely stopping/but not expressway). Filled with Sunoco, this morning, mid-grade...89 octane...we'll see if it goes back up to 15.4 mpg.

Brian.

 

Hi Min

If I ever get 16mpg or even 17mpg max I'd be devastated!, I'm expecting at least 26mpg around town and 29-30mpg on a run.