Anyone gone to 37s from 35s that were same weight or lighter than their 35s?

[ColoradoCantu]

I have 35x12.5xR17 Toyo MTs that weigh 78lbs and looking to move to 37x12.5x17R Toyo RT Trail that weigh 76lbs. Curious what this would do to my mpg. Since I cover more distance at basically the same weight as the older 35s with the 37s, could I possibly get better mpg or is it wishfool thinking?

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[Freems]

I have 35x12.5xR17 Toyo MTs that weigh 78lbs and looking to move to 37x12.5x17R Toyo RT Trail that weigh 76lbs. Curious what this would do to my mpg. Since I cover more distance at basically the same weight as the older 35s with the 37s, could I possibly get better mpg or is it wishfool thinking?

I would think the wishful thinking, could work out, if; you remove as much weight from the vehicle as possible. Make sure your air pressure is Perfect on all corners. ATs and especially MTs should be rotated every 1500 miles (even wear equals less rolling resistance). The more challenging is more size equals more air to move, it’s almost as bad as unsprung weight and you are doing both.

 

[Camaroboi13]

I saw no gains going from heavy 37s to lighter 37s, still at 22ish mpg. Can’t say anything for 35s as I went from 32s all the way up. You’ll love the RT Trails though, very smooth tires.

 

[Rahkmalla]

Most of a tire's weight is in the treads. So even if it's the same weight, it's now further away.

It's all about ftlbs (or lbft for you British types)

Just like using a longer wrench makes turning a seized bolt easier, imagine you're doing it the opposite way. Turning a wrench from the bolt's position rather than the handle. Would it be easier to turn a 1 foot wrench from the center, or a 2 ft wrench from the center?

That's what's happening with your tires.

Your MPGs will go down because the required torque to turn your tires/wheels goes up.

 

[madesicc88]

I went from 35in Ridge Grapplers to 37in KO2s off a Bronco Raptor and have noticed a small increase in MPG, I have stock 4.10 gearing. I don’t do a ton of interstate travel but when I do, I am still able to get 8th gear just as often as I did with the 35s. I have been really happy with the change.

 

[Joaquin1970]

I have 35x12.5xR17 Toyo MTs that weigh 78lbs and looking to move to 37x12.5x17R Toyo RT Trail that weigh 76lbs. Curious what this would do to my mpg. Since I cover more distance at basically the same weight as the older 35s with the 37s, could I possibly get better mpg or is it wishfool thinking?

I’m going to say you won’t have much if any appreciable difference. It’s not just the weight of the tire, but it’s the amount of torque required on the drivetrain to get rotation. I hate to be that guy, but if you’re driving a jeep with even 35s or 37s and fuel mileage is your concern, you’re probably driving the wrong vehicle. I say this at a personal experience because I had to come to a point of acceptance that, I was not going to get the best of both worlds and a gladiator. I went to a junker commuter car to help mitigate some of those miles but your situation might be different. I understand.

 

[Flanders]

Your MPGs will go down because the required torque to turn your tires/wheels goes up.

Nope. Fuel economy may well be affected but it won't be because of this.

A larger tire turns slower at the same vehicle speed. The radius cancels out completely.

The energy required to accelerate the vehicle to a fixed speed is exactly the same with tires of equal mass, regardless of diameter. Of course that statement assumes something about the distribution of mass over the tire. It is possible that the larger tire could be more efficient.

 

[Bjeepz]

I went from Falken AT3W 35’s to Cooper AT3 XLT 37’s. I think the Coopers are 2-3lbs lighter.. Gas mileage definitely didn't improve. In town or on trails it seems a little worse. On the highway it seems a little worse. I would guess about 2mpg worse in town and 1 mpg worse on the highway. Looks better though! The extra inch of clearance under everything is a nice perk also.

 

[ColoradoCantu]

I’m going to say you won’t have much if any appreciable difference. It’s not just the weight of the tire, but it’s the amount of torque required on the drivetrain to get rotation. I hate to be that guy, but if you’re driving a jeep with even 35s or 37s and fuel mileage is your concern, you’re probably driving the wrong vehicle. I say this at a personal experience because I had to come to a point of acceptance that, I was not going to get the best of both worlds and a gladiator. I went to a junker commuter car to help mitigate some of those miles but your situation might be different. I understand.

Your are 100%. I have accepted the fact that ill be visiting gas stations more frequently. Im not worried about mpg, I was just curious, its our third vehicle along with a GMC Acadia and Nissan Maxima.

 

[ColoradoCantu]

I saw no gains going from heavy 37s to lighter 37s, still at 22ish mpg. Can’t say anything for 35s as I went from 32s all the way up. You’ll love the RT Trails though, very smooth tires.

Any idea what your jeep weighs? I'm easily 1000lbs over stock. Doesn't help that I'm in Colorado with thinner air and not a lot of Texas type flat roads. I get way better MPG in TX when visiting family.

 

[Camaroboi13]

Any idea what your jeep weighs? I'm easily 1000lbs over stock. Doesn't help that I'm in Colorado with thinner air and not a lot of Texas type flat roads. I get way better MPG in TX when visiting family.

I might be 300-400 tops over stock overland diesel weight, I don’t carry a lot unless it’s trip day. My recovery gear that I can fit under the seat stays there at all times, and I have a compressor in the bed plus steel bumpers and winch and sliders. That’s about all the extra weight I carry.

 

[Joaquin1970]

Your are 100%. I have accepted the fact that ill be visiting gas stations more frequently. Im not worried about mpg, I was just curious, its our third vehicle along with a GMC Acadia and Nissan Maxima.

I’m rocking a 2001 Lexus iS300 that gets 22mpg. Original family owned with 90,000 miles. It’s better than 12!

 

[Camaroboi13]

I’m rocking a 2001 Lexus iS300 that gets 22mpg. Original family owned with 90,000 miles. It’s better than 12!

I get the same mpg on 37s and 4.5” lift

 

[Joaquin1970]

I get the same mpg on 37s and 4.5” lift

that’s awesome! What’s the best speed for you to achieve that? I found my newly purchased Gladiator (currently stock 33’s) is great under 70mph: 19.5mpg (in Florida). At 71+ mph, I can feel the “wall” and the mileage starts dropping rapidly down to 15mpg.

 

[Camaroboi13]

that’s awesome! What’s the best speed for you to achieve that? I found my newly purchased Gladiator (currently stock 33’s) is great under 70mph: 19.5mpg (in Florida). At 71+ mph, I can feel the “wall” and the mileage starts dropping rapidly down to 15mpg.

I set my cruise control at 74 usually. Any higher and it starts falling off.

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