MPG hit with Toyo AT3s 35x11.5x17 with 3.73s??

[Garemlin]

First off no I didn't buy the Gladiator as a fuel efficient vehicle. But MPG is a legitimate concern with ever rising gas prices. Every MPG helps.

So I see the Toyo AT3s in 35x11.5x17 are a pretty popular size on the Gladiator. Just wondering how much of a hit you took, if any, on your gasser Gladiator with 3.73 gears.

I currently get 18.5-20 running Kenda Klever AT2s in 285/70-17 local driving. They weigh in at around 47lbs. The Toyos weigh 63lbs from what I have seen.

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[Jerhemi]

queue all the re-gear responses.

 

[Wheelin98TJ]

I lost 2-3 MPG going to 35x12.50. With 3.73 gears.

Was getting 20-21 when stock, currently getting 17-18.

 

[Painkillerspe]

I will have 35/10.5/17 installed soon with 3.73. I can report back on my results. The lift I put on already ate up 1.5 mpgs. Getting around 17 now.

 

[Mac]

I saw about a 5mpg hit going from the stock Bridgestone tires to Toyo AT III 34x11.5x17 and the same with Kenda 35x10.5x17s. Stock was about 23 in mixed driving, now at around 18mpg, have 22k on my JT.
I have 4.10s though not 3.73s.

 

[Josh00333]

I'm bout the same, maybe -4mpg. 22ish factory tires, 18ish w 285/75r17 (34") and 4.10's.

I saw about a 5mpg hit going from the stock Bridgestone tires to Toyo AT III 34x11.5x17 and the same with Kenda 35x10.5x17s. Stock was about 23 in mixed driving, now at around 18mpg, have 22k on my JT.
I have 4.10s though not 3.73s.

 

[dcmdon]

Gearing down (higher numerical ratio) will NOT help fuel economy. The engine will rev higher in top gear which will hurt highway fuel economy.

This may even out if you aren't currently even running in 8th on the highway. But the bottom line is that the slower the motor is turning at a given speed, the better your fuel economy is.

Engineers and manufacturers work to balance this fact with the need for decent acceleration. If all you cared about was fuel economy, you would be geared to run at full throttle at something like 1300 rpm when you were on the highway.

 

[Jerhemi]

Gearing down (higher numerical ratio) will NOT help fuel economy. The engine will rev higher in top gear which will hurt highway fuel economy.

This may even out if you aren't currently even running in 8th on the highway. But the bottom line is that the slower the motor is turning at a given speed, the better your fuel economy is.

Engineers and manufacturers work to balance this fact with the need for decent acceleration. If all you cared about was fuel economy, you would be geared to run at full throttle at something like 1300 rpm when you were on the highway.

My joke was more about people who insist you need to re-gear when running 35"s on 3.73.

 

[Gren71]

https://www.jeepgladiatorforum.com/forum/threads/worth-it-to-go-back.47891/

Food for thought

 

[dcmdon]

My joke was more about people who insist you need to re-gear when running 35"s on 3.73.

I wasn't really replying to you. Just the general belief that occasionally pops up that if you put bigger tires on you can get some of the fuel economy back by re-gearing. You can't. You may get some of the performance back though.

 

[Wheelin98TJ]

I wasn't really replying to you. Just the general belief that occasionally pops up that if you put bigger tires on you can get some of the fuel economy back by re-gearing. You can't. You may get some of the performance back though.

I regeared a TJ from 3.07 to 4.56 and picked up 2 MPG.

 

[Mac]

I wasn't really replying to you. Just the general belief that occasionally pops up that if you put bigger tires on you can get some of the fuel economy back by re-gearing. You can't. You may get some of the performance back though.

You can and it has been stated many times on this forum.
What tires are you running on your JT and what other Jeeps have you had and changed tire size and gears on?

 

[dcmdon]

You can and it has been stated many times on this forum.
What tires are you running on your JT and what other Jeeps have you had and changed tire size and gears on?

Jeeps obey the same laws of physics as every other vehicle. Turning an engine faster almost ALWAYS results in a higher specific fuel consumption. (gal per hour per hp) The crux of it is whether the motor in the vehicle makes a given amount of power with less fuel by running higher manifold pressure (more torque) and fewer RPMs in a higher gear
or by running lower manifold pressure and higher RPM with lower gearing, it needs to make a given amount of power to move the vehicle down the road.

Why do you think that manufacturers keep putting higher and higher (lower numerically) final drive ratios in vehicles? Its to get better fuel economy. Putting bigger tires makes the gearing taller because the vehicle travels more distance for a given revolution of the tire.

 

[johnparjr]

I know I lost about 5 mpg going to a MT tire so when these are done all will go back to a AT type

 

[dcmdon]

I know I lost about 5 mpg going to a MT tire so when these are done all will go back to a AT type

Wow. Was that just a change from AT to MT or did you go up in size.?

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