Gearing with 35s

[BroncoFanBoy]

Without knowing pricing I am considering the BD with Sasquatch or just doing a lift/tires aftermarket. My question is about the gears that come with the BD, 4.46. This would work just fine with 35s, right? The 4.46 would get better MPG than 4.70 but maybe feel like less power, am I understanding that correctly?

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[kodiakisland]

All depends on what you're going to do with it. For me, the gears are too high, but I spend a fair amount of time in 4wd under 10 miles an hour. I rarely go over 65mph. I need low gears.
For people that are going to get the auto and mostly drive highway, they'll make do with the higher gears even if it's a little slow or underpowered on takeoff.

 

[Goocci gang]

Without knowing pricing I am considering the BD with Sasquatch or just doing a lift/tires aftermarket. My question is about the gears that come with the BD, 4.46. This would work just fine with 35s, right? The 4.46 would get better MPG than 4.70 but maybe feel like less power, am I understanding that correctly?

If u have a manual you can make anything work. I had 3.21 gears on my jku for a year and it was fine with 35s, I just didn't use 6th gear.

 

[Stampede.Offroad]

If u have a manual you can make anything work. I had 3.21 gears on my jku for a year and it was fine with 35s, I just didn't use 6th gear.

One of the benefits of the 10sp is the wide range and fine granularity of gearing possible with so many to choose from.

 

[Chamberlin]

One of the benefits of the 10sp is the wide range and fine granularity of gearing possible with so many to choose from.

And let's hope there'll be a tuning tool we can plug in to the ECU and reprogram the speedo and shift points based on final drive ratio and tire circumference!

 

[NCOBX]

I think it’s worth saying that being under geared is much worse than too much.

For example if you have a vehicle that comes from factory with 4.10s and stock 315/70(34.4in) with stock fuel economy at ~11.8MPG and go up to 37x12.5 your gas mileage will suffer. In my case it went down to about 10.5.
Going up to 4.56 netted me 13-13.5MPG with same tires
For similar Setup on 4.88s it was reported people were getting about 11.5.

You never want too little gearing, not only does your fuel economy suffer but your entire driveline has a greater amount of stress.

 

[CumminsWayne]

Not trying to hijack the thread, but how do you guys feel the 4.7 gears from the Sasquatch will do if bumped up to 37’s? MPGs better or worse on the highway?

 

[NCOBX]

Not trying to hijack the thread, but how do you guys feel the 4.7 gears from the Sasquatch will do if bumped up to 37’s? MPGs better or worse on the highway?

Unless your gearing is already too high your not going to get better fuel economy moving up a size in tires.

As far as what is the “Right” amount of gearing, it’s not only affected by tire size but also engine size. A 6.0L V8 will turn 37s at 80MPH @ 2,350 RPM All day long and not skip a beat. A 4 cylinder Toyota may need 3,400 RPM @ 80MPH to do the same job.

The wild card here is the turbos, if your RPM is too low your going to stress the vehicle components and not be in the turbos sweet spot. If your RPM is high enough to be in the turbo sweet spot your fuel economy is going to suck because your into the turbocharger for what should be cruising speeds.

 

[CumminsWayne]

Unless your gearing is already too high your not going to get better fuel economy moving up a size in tires.

As far as what is the “Right” amount of gearing, it’s not only affected by tire size but also engine size. A 6.0L V8 will turn 37s at 80MPH @ 2,350 RPM All day long and not skip a beat. A 4 cylinder Toyota may need 3,400 RPM @ 80MPH to do the same job.

The wild card here is the turbos, if your RPM is too low your going to stress the vehicle components and not be in the turbos sweet spot. If your RPM is high enough to be in the turbo sweet spot your fuel economy is going to suck because your into the turbocharger for what should be cruising speeds.

Sorry, I should have worded that Differently. I meant as you stated “right amount of gearing”.Just wondering if the 37’s paired with 4.7 gears would be a better pairing (mpgs on highway/low end power) than 35’s and 4.7 gears. Just want get whichever tire will better be in the sweet spot. Thanks for your input!

 

[NCOBX]

Sorry, I should have worded that Differently. I meant as you stated “right amount of gearing”.Just wondering if the 37’s paired with 4.7 gears would be a better pairing (mpgs on highway/low end power) than 35’s and 4.7 gears. Just want get whichever tire will better be in the sweet spot. Thanks for your input!

I don’t think 37s would be highly detrimental to fuel economy but the factory isn’t going to give you “too much” gearing it hurts their bottom line CAFE scores which they suck off on like a cheerleader to the football team.

I think you would lose a small amount of fuel economy but not enough I would worry over.

 

[MEMessina72]

My 2 cents... going from 35" to 37" with 4.7:1 and the 10 speed.... you wont notice much loss in power and you wont notice much fuel mileage improvements or decreases unless you're going a super heavy and wide tire.

I think if youre going with a 37x12.5r17 or similar and keep the tire weight in the low to mid 70 lbs range you'll be ok. Start adding steel wheels ar 32+ lbs.... well... you'll start seeing things. More spinning mass=slower stopping, ect.

Again my 2 cents.

Personally.... if I dont like the Sasquatch wheels I'm going old school American Racing Outlaw II at 26.5lbs and 17x8 with 4.5" backspacing.

 

[Clark]

My 4Runner is a gutless pig on the highway on 4.88s and 33s. Off-road though, put it in low, point it and it just goes. I push almost 3k RPM at 75 MPH. I get around 11-13 MPG. I can’t imagine what a slug it would be with 35s.

The Bronco has buckets more power than my runner, even with the 2.3, so those 4.7 gears with 35s will be amazing. 4.46 will definitely work more than fine, and most wouldn’t know the difference unless they drive a model with 4.46 gears and then one with 4.7, both having the same 35” tires.

I’m doing my best to end up with that 2.7, 4.7s, 10spd and 35s. ?

 

[NCOBX]

My 4Runner is a gutless pig on the highway on 4.88s and 33s. Off-road though, put it in low, point it and it just goes. I push almost 3k RPM at 75 MPH. I get around 11-13 MPG. I can’t imagine what a slug it would be with 35s.

The Bronco has buckets more power than my runner, even with the 2.3, so those 4.7 gears with 35s will be amazing. 4.46 will definitely work more than fine, and most wouldn’t know the difference unless they drive a model with 4.46 gears and then one with 4.7, both having the same 35” tires.

I’m doing my best to end up with that 2.7, 4.7s, 10spd and 35s. ?

Jeez I’m on 37s with 4.56 and getting 12.5-13.5MPG on an H2. But then I’m only pushing 2,450RPM at 80MPH.

What year is it?

 

[Clark]

Jeez I’m on 37s with 4.56 and getting 12.5-13.5MPG on an H2. But then I’m only pushing 2,450RPM at 80MPH.

What year is it?

Yeah, I probably should be somewhere around the 4.56 neighborhood for gearing in my Runner, but I didn’t want to lose out on the low end power curve.

 

[rynomar]

I was just comparing high range drive ratio's of the Bronco against the Wrangler Rubicon. One of the things that really stands out to me is the drive ratio for the manual in 2WD. First gear is only going to give you 13.1:1 compared to 22.2:1 in the Automatic. It will be very interesting to see how the 2.3L handles off the line in 2WD.

I had a 2012 4 door Rubicon on 37's with the manual. It really struggled on steep terrain in the factory setup (First Gear 5.13, 4.1 axles = 21.0:1). I ended up switching the front and rear gears to 4.38:1 (22.5:1), which worked much better, but I would say that was the minimum needed for my setup.

I know this is not an apple to apple comparison and I am sure the factory gearing will work just fine with 32"-33" tires, but that is going to put a lot of stress on the clutch with 35" or larger tires during normal driving. Of course, the Crawler gear will be fantastic, but I don't know how well that will work out for everyday driving.

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