Mileage Difference (1 Viewer)

[LCH21]

Just got back from my Florida trip. I used my Garmin Tread XL to compare actual mileage per the GPS and the odometer's indicated mileage. Running the BFG KO2 in 285/68R18, for every 1000 miles indicated on the odometer, the GPS measured 1040 miles, slightly more than the 3.6% difference in the tire size compared to stock. At 80 MPH indicated, the GPS stated 81 MPH. I would have thought it would have been closer to 83 MPH.

Fuel mileage was interesting. I drove 4355.5 miles per GPS and used 245.9 gallons. Overall, 17.7 MPG. Highway driving at the posted speed limits, mostly between 75 and 80 MPH, I averaged in the mid 18's, with one tank from Tucson to Quartzite at 19.8 MPG. Lowest highway mileage was during some nasty thunder bumpers between Ft. Stockton, TX and El Paso TX, at 15.7 MPG. A headwind and pushing that water out of the way with those fat tires makes a difference, even though I was driving at around 50 MPH. I do think that the Slee skids smoothing out the airflow underneath makes a difference on the highway.

Just realized, like an idiot, I did not get any pictures of the LC at Pensacola Beach. Did get to watch the Blue Angels practice.

 

[gaijin]

When your LC200 was stock, with OEM 285/60R18 tires, the odometer was accurate; but, due to Japanese Motor Vehicle Standards, the speedometer was set to read about 2-3% faster than actual.

The offshoot of this is that when larger diameter than OEM tires are fitted, the odometer reads some percentage less than actual miles travelled while the speedometer reads some percentage closer to actual speed.

That's why (as you found out) the best way to calculate gas mileage is to use GPS distance - the GPS doesn't care how large (or small) your tires are.

HTH

 

[MRego]

Just got back from my Florida trip. I used my Garmin Tread XL to compare actual mileage per the GPS and the odometer's indicated mileage. Running the BFG KO2 in 285/68R18, for every 1000 miles indicated on the odometer, the GPS measured 1040 miles, slightly more than the 3.6% difference in the tire size compared to stock. At 80 MPH indicated, the GPS stated 81 MPH. I would have thought it would have been closer to 83 MPH.

Fuel mileage was interesting. I drove 4355.5 miles per GPS and used 245.9 gallons. Overall, 17.7 MPG. Highway driving at the posted speed limits, mostly between 75 and 80 MPH, I averaged in the mid 18's with one tank, from Tucson to Quartzite at 19.8 MPG. Lowest highway mileage was during some nasty thunder bumpers between Ft. Stockton, TX and El Paso TX, at 15.7 MPG. A headwind and pushing that water out of the way with those fat tires makes a difference, even though I was driving at around 50 MPH. I do think that the Slee skids smoothing out the airflow underneath makes a difference on the highway.

Just realized, like an idiot, I did not get any pictures of the LC at Pensacola Beach. Did get to watch the Blue Angels practice.

17.7mpg? What kind of black magic are you using? I have the same 285/65s, but KO3s, don’t have any aftermarket skids, just OEM and have sliders, in my last trip to big bend I was doing about the same speed as you and was lucky to get 14.5mpg in one of the tanks. I do have the Yakima rack on top with two traction boards strapped to it though. Is it possible just the rack would cause such a difference?

 

[LCH21]

17.7mpg? What kind of black magic are you using? I have the same 285/65s, but KO3s, don’t have any aftermarket skids, just OEM and have sliders, in my last trip to big bend I was doing about the same speed as you and was lucky to get 14.5mpg in one of the tanks. I do have the Yakima rack on top with two traction boards strapped to it though. Is it possible just the rack would cause such a difference?

That rack on top is worth a couple or three MPG at freeway speed. That is why I took mine off unless I need it. My last trip to Montana with the kayaks on top saw similar gas mileage as you got.

Forgot to mention: I did notice about a 2 MPG increase on the highway after installing the Slee skids.

 

[MRego]

That rack on top is worth a couple or three MPG at freeway speed. That is why I took mine off unless I need it. My last trip to Montana with the kayaks on top saw similar gas mileage as you got.

Forgot to mention: I did notice about a 2 MPG increase on the highway after installing the Slee skids.

Ahm, makes sense. Good to know. Contrary to most, I really like the looks of the basket and it’s great not to have the boards taking space in the trunk. Those suckers are bulky.

 

[skrypj]

17.7mpg? What kind of black magic are you using? I have the same 285/65s, but KO3s, don’t have any aftermarket skids, just OEM and have sliders, in my last trip to big bend I was doing about the same speed as you and was lucky to get 14.5mpg in one of the tanks. I do have the Yakima rack on top with two traction boards strapped to it though. Is it possible just the rack would cause such a difference?

I’ve gotten slightly over 18 mpg many times in mine, hand calc’d, driving 75-80 mph freeways. Thats on 315/70R17 Goodyear territory MT’s and full Victory4x4 skids.

Driving at 75-80 mph actually seems to be the only time these trucks actually get decent MPG’s. Everywhere else I get worse mpg. Even the 55 mph 2 lane back roads around my house I seem to get 16-17 mpg.

 

[LCH21]

Ahm, makes sense. Good to know. Contrary to most, I really like the looks of the basket and it’s great not to have the boards taking space in the trunk. Those suckers are bulky.

I have to admit that I like the look too, but here in So Cal, at 5 bucks a gallon, I have to cut back where I can!

 

[MRego]

Ouch. Yeah, I still have the luxury of $2.89 a gallon here in TX.

I have to admit that I like the look too, but here in So Cal, at 5 bucks a gallon, I have to cut back where I can