How do 35's affect MPG and towing

[JustJimmy]

Curious about those two things.

4" lift
Tow rating effect Sport S max tow package.

Mpgs as well.

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[willemlock]

I can’t talk for towing but I saw a 2mpg drop with my 35’s. Keep in mind I run 37psi so I’m sure if I was to run 45 it will be better but I prefer the ride at 37psi.

 

[Yellow1098]

I have learned about the computer reset you need to when you upgrade the tire size....I think this should help the MPG slightly....I not sure how to get it done though...would the tire shop do this or would it have to be a dealership?

 

[WXman]

I saw a 2 MPG decrease with mine on 35s. Doesn't sound like much but it adds up over time. $$$.

 

[PyrPatriot]

I can’t talk for towing but I saw a 2mpg drop with my 35’s. Keep in mind I run 37psi so I’m sure if I was to run 45 it will be better but I prefer the ride at 37psi.

There are folks on the book of faces JT groups claiming 22-23mpg at 75mph highway on 35s. I dont belie them

 

[smoverland]

There are folks on the book of faces JT groups claiming 22-23mpg at 75mph highway on 35s. I dont belie them

I get nearly 20mpg on the highway and I'm on 38s.

 

[WXman]

There are folks on the book of faces JT groups claiming 22-23mpg at 75mph highway on 35s. I dont belie them

The only way somebody will see 20+ MPGs on 35s or larger is if they live in Kansas, of if they're driving downhill. Ain't happenin'. I've tracked MPGs religiously on dozens of 4x4s over the last 15 years and I've experimented with lots of aero and engine mods and those inflated MPG numbers simply aren't happening unless you live in an area with NO hills and valleys.

 

[PyrPatriot]

I recall when I looked into this issue that you lose about 10% of towing capability with every inch of tire increase. I made a thread about it somewhere. Basically larger tires means the engine works harder due to unsprung weight and larger circumference to move. Going from 31.5 to 35s with lift would be about 40% less towing ability. Wait that doesnt sound right...

https://www.jeepgladiatorforum.com/...ze-gear-ratio-affect-on-payload-towing.24058/

 

[BuckSawLilandtheGoose]

I have 35in MT tires and get 11 mpg average since purchase. I just broke 4k miles yesterday. I almost never drive on highway though.

 

[Kendog689]

I average 16.2 in town and 13.1 on the highway.

 

[ShadowsPapa]

You can't just talk tires and not talk the level of JT - the original gear ratio will determine how much impact larger tires will have.
35's on an Overland will be a big impact on towing as it's already on the edge - might negatively impact MPG, too where the 4.10s will be helped by larger tires as far as MPG - unless really aggressive tires. IMO.

 

[Kendog689]

You can't just talk tires and not talk the level of JT - the original gear ratio will determine how much impact larger tires will have.
35's on an Overland will be a big impact on towing as it's already on the edge - might negatively impact MPG, too where the 4.10s will be helped by larger tires as far as MPG - unless really aggressive tires. IMO.

I have a 3" front lift,a 3/4 rear lift with the max tow package.35/12.5 Goodyear Wrangler zero,s.

 

[MarineHawk]

The stock tires on mine weighed 63 lbs, and the stock wheels apparently weighed 28 lbs, for a total of 91 lbs (not including balancing weights).

My replacement 35” Cooper STTs weigh 67 lbs, and my replacement wheels weigh 26 lbs, for a total of 93 lbs (not including balancing weights).

So, I increased my tire/wheel combo weight by about 2%.

I assume that increasing tire weight has more of impact on mileage than increasing wheel weight because of the greater moment arm for the increased weight of the tire, as opposed to the wheels, which are closer to the center-axle line.

Nevertheless, this overall 2% increase in tire/wheel weight has produced no material noticeable difference in MPGs in mine. I can't say that it hasn't gone down at all, because it's almost impossible to prove. However, running the same routes, under similar climate and traffic conditions as before generally produces the same average mileage as I got on my stock setup.

I suspect that if I had put 34-lb wheels on my JTR, like I had on my GMC Sierra for some reason, my MPGs would have gone down enough to notice.

 

[ShadowsPapa]

The stock tires on mine weighed 63 lbs, and the stock wheels apparently weighed 28 lbs, for a total of 91 lbs (not including balancing weights).

My replacement 35” Cooper STTs weigh 67 lbs, and my replacement wheels weigh 26 lbs, for a total of 93 lbs (not including balancing weights).

So, I increased my tire/wheel combo weight by about 2%.

I assume that increasing tire weight has more of impact on mileage than increasing wheel weight because of the greater moment arm for the increased weight of the tire, as opposed to the wheels, which are closer to the center-axle line.

Nevertheless, this overall 2% increase in tire/wheel weight has produced no material noticeable difference in MPGs in mine. I can't say that it hasn't gone down at all, because it's almost impossible to prove. However, running the same routes, under similar climate and traffic conditions as before generally produces the same average mileage as I got on my stock setup.

I suspect that if I had put 34-lb wheels on my JTR, like I had on my GMC Sierra for some reason, my MPGs would have gone down enough to notice.

The tread of the tire is moving faster so there's more inertia to overcome both accelerating and decelerating than with the wheel - the engine has to spin them. It's like in racing - take a THM400 for example, you put in lighter gears so there's not as much weight in the transmission to get spinning up to speed - can accelerate them faster. So you use light gears in transmissions for racing and performance, take out the heavy stuff. Light wheels accelerate faster and take less engine to do so.

 

[Superduty]

I average 16.2 in town and 13.1 on the highway.

Do you have those numbers reversed?

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