Fuel mileage and tire tread style?

[Niki]

Has anyone seen a gain/loss of fuel mileage when switching tread patterns on a same size tire? I'm thinking of running BFG Mud terrains on the road and have always ran all terrains, so I'm curious if the Mud terrains blocky tread design will increase rolling resistance, although the all terrains tread seems to flex more and has more tiny grooves. Any input is appreciated, especially those who have gone from a smoother on road style tire to an all terrain or mud tire.

 

[JLEONARD]

There's lots written about that in various places. More agressive tread steals mileage period.

 

[SAndreasen]

i recently changed my 01 over from an all terrain to toyo mud terrains and the are way aggressive i am not for sure yet but the last few tanks have been almost 2mpg less than my normal 17. 5 . however i did have an o ring on an injector cross over tube bad and this last trip loaded 13,000gvw using stanadyne i got 11. 42 so it may have been the o ring costing mileage im sure it didnt help. i am going to keep checking my milage and see if it comes back up

 

[HSpiering]

Had 245 town/country on my 94 4X4. Changed to 265 wild country and lost 1. 5 MPG. Then changed to Toyo M-55 and lost about one more. First tires had more road surface and then more aggressive tread. Thinner ,smother and harder= better milage.

 

[KOG]

When you change size, all bets are off. Just a change of tread design alone on a tire with similar carcass construction will not make much of a difference. Changing from a 245 to a 265 without correcting your speedometer and odometer will show you a significant apparent loss. Just putting new tires with full tread depth on will typically cause an apparent loss of as much as 7-8% because you're traveling both faster and further for the same speedo and odo readings. You wouldn't think that another 3/8" of tire radius would make that much difference, but do the math, I have. It really matters that much. And then there;s the fact that a new deep tread squirms more and has somewhat higher rolling resistance as well. I first did the figuring on this about 25 years ago when a friend put new tires on his Dodge Omni and called me to find out why the mileage had dropped about 10% on the highway. He was convinced that something had gone wrong with the engine or transmission. I went through it and then drove it for a couple of days (about 500 miles) and could find nothing wrong. I then pulled out the calculator and started figuring the effect on speed and distance of the new tread. That turned out to be the problem. Same exact tires were used for replacement which made it possible to know exactly what the difference was.

When you change brand, size, load rating you can forget being able to figure what happened. You've just changed something that you can't entirely calculate.

 

[HSpiering]

Been there Did that. I added 3% For tire size change also, road test mile markers many times. Tires bigger I should get better milage but lost because wider and tread. Hand calculated for over 12 years every tank.

____________________________________

06 4X4 std cab Inferno red

 

[KOG]

Thinner, smoother and harder (as well as narrower and taller) do equal better mileage, as HSpiering reports, IF all other factors are equal. But when you change brands and carcase construction, all bets are still off, as I mentioned. Again, tread design alone doesn't necessarily make a huge difference in rolling resistance. More aggressive treads with a higher void ratio (more open space in the tread) often have deeper tread as well to offset the higher wear rate you get with less tread rubber contacting the road. Deeper tread, as both HSpiering and I have noted, will definitely increase your rolling resistance as well as rolling radius. And those things will cut both real and indicated mileage significantly.

 

[Niki]

I've had 2 Dodges I've driven daily and changed out tires on, but they have never been the same size or style, not even close. I had a 95 w/ 4. 10 gears that I put 315/75-16 all terrains on, took the stock 245/75 car tread donuts off and my mileage increased at least 2 mpg after I corrected for tire height. That probably had more to do with the motor not screaming on the highway anymore though. I had a 93 w/ 3. 54's that I had 265's on and put 285 all terrains on and I think It stayed about the same, maybe lost . 5-1 mpg. In both of those cases though I went from E range(80 psi) to D range(50-65 psi) too, I'm sure that makes a difference. I wonder if in the stock size(235/85-16 E) if tread design matters as much since they are so narrow and you can get almost all brands in E range(80 psi)?

 

[Niki]

Had 245 town/country on my 94 4X4. Changed to 265 wild country and lost 1. 5 MPG. Then changed to Toyo M-55 and lost about one more. First tires had more road surface and then more aggressive tread. Thinner ,smother and harder= better milage.

What did you think of the toyo M-55's? I looked at the tread, didn't look that aggressive. I was thinking of getting those in a 255/85-16 size.

 

[HSpiering]

I live in W Oregon. 4 times I got flats in the hills and desert East of here. Once antelope hunting I had chunks out of the edge of the tires. Every time I went to Less Schwab ( different towns) I was told all the ranchers miners loggers use m-55. They have a belt to help prevent rock damage and their tuff. So I got a good deal and bought a set. It also help at selling the truck. I got my new one in E Oregon and the sales person was happy to get m-55. Now the bad part, I only put 7k on them so I can't tell to much. I did talk to a state trooper and they use m-55 on their pickups. I would like to get then again but they are big $$$. ,and I did lose diesel milage. I sure did feel better in the hills and desert areas.

 

[SAndreasen]

milage still is down 2 mpg with the new toyo mud terrains with a gps corrected speedometer . i am going to running 90 psi front and rear because i lowerd the psi and lost another mile per gallon sure did ride nice though. i dont know what else to do i am going to swap my tires and wheels with some toyos ats and see if that brings the milage back up from 15. 5 with the mts and 17. 5 before

 

[Moab4x4]

265's Mud tire load range E to BFG AT in 285. Smoother tread, wider tread, load range D IIRC, softer tire, I lost 1 MPG after correction. Lots of variables.

Better offroad for what I do though.