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

[JTBurns]

How you drive is going to affect it more than anything. It seems like switching from MT to AT or to the skinnier tire, there really may not be a huge difference. I'm likely going to do this when my falken MTs wear out. I'm usually at about 17.5 with those and the 3.73s but if I drive with just a little more spirit I can quickly get back to 16. Almost always lose 1.5 mpg if the wife takes the truck anywhere. Plus "highway" driving can be deceiving. I find the truck loves going 55-60 maybe 65, but once at 75+, that highway efficiency is gone.

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[texanjeeper]

From the research I've done, going from the smaller tires to 35's with 3.73 gears is going to cause you all kinds of problems. Your Jeep is struggling to try to shift out of 6th gear on the highway into 7th, and from the multiple sources I've read about, you'll never see 8th gear, or at least very rarely. That's why I've decided to only go with the 33 inch tires until such time as I could afford a re-gear which may never happen.

 

[Higher_Ground]

YMMV but went from was stock (3.73 gears + Bridgestone Dueler HT) and upgraded the tires to Toyo Open Country AT3s in the 285/75/17 size. I lost a decent amount of mileage driving around town. I don't really do as much highway driving so I can't compare but on occasion it's been more less where it was before (low to mid 20's). Most of my loss was in city driving (accelerating/decelerating/idling).

I do worry if it's a bit too much work for the engine driving around town at low RPM. I hear it knock regularly on 87 octane when it's in 3rd gear ~1500 RPM and I try to accelerate. I don't know if changing the tires may have contributed to it or if it's just coincidence. I did reset my tire size when I changed them.

 

[Aonarch]

Shit, I'm on E85 with 35s. I don't ever look at the mpg gauge, because it isn't pretty.

 

[49Gramps]

So tell me, why do we have Jeeps if we're so worried about mileage? 35s with 3.73s make decent mall-crawlers, but what about some real off-roading now and then? Some 4 pages so far going on and on about mileage, getting into 8th gear (or 6th for sticks), and so on, but nobody has said squat about the difference 35s with 3.73s make when doing any serious off-roading! Sure, you'll have more ground clearance, but you'll also be riding your brakes whenever you're trying to crawl slowly over obstacles. Face it, if you're doing any serious rock crawling with 35's, especially with a 2.72 transfer case, you really should think about going to at least 4.56s!

 

[Jerhemi]

So tell me, why do we have Jeeps if we're so worried about mileage? 35s with 3.73s make decent mall-crawlers, but what about some real off-roading now and then? Some 4 pages so far going on and on about mileage, getting into 8th gear (or 6th for sticks), and so on, but nobody has said squat about the difference 35s with 3.73s make when doing any serious off-roading! Sure, you'll have more ground clearance, but you'll also be riding your brakes whenever you're trying to crawl slowly over obstacles. Face it, if you're doing any serious rock crawling with 35's, especially with a 2.72 transfer case, you really should think about going to at least 4.56s!

Speaking for myself, I am older now and this Jeep is my DD. It will see some mud and backroad trails, but nothing crazy. Last thing I plan to do is rock crawl with it. I’m not really concerned with MPG, or I would have stayed in my F150. Set of 35’s and a 2” spacer lift is what I plan on.

 

[Garemlin]

So tell me, why do we have Jeeps if we're so worried about mileage? 35s with 3.73s make decent mall-crawlers, but what about some real off-roading now and then? Some 4 pages so far going on and on about mileage, getting into 8th gear (or 6th for sticks), and so on, but nobody has said squat about the difference 35s with 3.73s make when doing any serious off-roading! Sure, you'll have more ground clearance, but you'll also be riding your brakes whenever you're trying to crawl slowly over obstacles. Face it, if you're doing any serious rock crawling with 35's, especially with a 2.72 transfer case, you really should think about going to at least 4.56s!

I live in Delaware. There are no rocks. Even if there was I have zero interest in rock crawling. My off-roading is the beach and trail riding. You know just because people don't rock crawl and beat the crap out of their trucks doesn't mean they are mall crawlers.

And I'm not necessarily concerned with mileage. I just asked a simple question about mileage difference with a specific tire.

 

[Painkillerspe]

Just installed Kenda 35x10.5x17. Calibrated the computer to 34inch tires since it measures out to 34.5. GPS speed matches up with cruise control. Tested at 65, 70 and 75 miles per hour. So far I have not seen a performance hit. Still have 8th on the highway. Getting around 17.5 mpgs. Very impressive. Might not need a regear.

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