Falken AT3W LT 275/60 r20 mpg decrease

[Idahoktm]

As mentioned, everything you stated has played a role, but the biggest is the diameter of the tire and the type of tire it is. Larger tire and higher rolling resistance of the tread will both play a big roll in your lower mpg.

1/2 " increase usually results in a 1-2 mpg loss. So going a full 1" in diameter and losing 3.5 mpg is about right.

Nah, the diameter does not result in that big of a hit. I have 33's and I get about 17.5 mpg with an 80/20 city/highway split. No way could I get 21 mpg with stock tires. However, if you go to a 33" LT tire, you will certainly take that big of a hit. In that case, the weight of the tire is the biggest culprit.

 

[millerbjm]

Just another thought since you're in Maine are you comparing avg mpgs from summer fuel to new avg mpgs on winter gas? I take a hit of 2-3mpg with winter gas in MN.

 

[SD Rebel]

Nah, the diameter does not result in that big of a hit. I have 33's and I get about 17.5 mpg with an 80/20 city/highway split. No way could I get 21 mpg with stock tires. However, if you go to a 33" LT tire, you will certainly take that big of a hit. In that case, the weight of the tire is the biggest culprit.

Not with my experience. Even changing to slightly larger tires of the same exact model I had before, maybe 1/2" max resulted in very obvious mpg loss.

I think if you changed to 31-32" all season street tires, you will see 21 mpg with our RAMs. Plenty of guys already get that or better on similar tires, while at the same time Rebel owners with 33 A/T are seeing low teens mixed, maybe 17 on the highway if they take it easy.

I mentioned it's a combo of both size and tread type, 33" and A/T will big time drag down mpg compared to smaller L/T.

 

[Choate]

That’s why I went with the XL or standard load version of those. I didn’t notice much of any loss of MPG over stock. When I leveled it I did but not much. It’s totally the weight of those tires. That’s a lot of extra rotational mass

 

[Rebel2022]

My previous Ram was a 2018 Sport with 20” Goodyear wranglers, also 3:92 gears. I am surprised at the difference in rolling resistance in my new Rebel with duratracs compared to the goodyears. Letting off the gas on the highway feels like a parachute was deployed. Don’t know if its the compound, grips, weight or size probably all of them but the resulting hit in milage is pretty big, at least 30% worse in my case. I know the increase ride height and lack of a front lower chin in my Rebel have some affect but I feel like the tires are the bigger factor. Not complaining, I expected a hit just surprised that tires would make this much difference.

 

[Idahoktm]

That’s why I went with the XL or standard load version of those. I didn’t notice much of any loss of MPG over stock. When I leveled it I did but not much. It’s totally the weight of those tires. That’s a lot of extra rotational mass

Yep. Me and a buddy have the same truck and both are leveled with 33 XL's and we are seeing about 1 MPG drop at best.

 

[Dirtdoc]

For the OP, why did you go LT tires? If you need them fine but the p rated aired up to their max serve the majority of our needs. As you found out they are way heavier which kills mpg's.