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Questions about Wildtrak on 37s (Don’t yell- I’m new to this ?)

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I absolutely love the look of the Bronco with the 2” lift sporting 37s. I don’t know what model it’s on, but wanting to do that on a 4 door WT.

Please give me a little grace here- I know absolutely nothing about the technical aspects of the 4X4 world, but I want my Bronco to look large and in charge.

I do very little off the beaten path, but I do spend most of my time in and around the mountains of Colorado & Montana (fishing, hunting, etc.). So, here are my very novice questions...

What lift will I need for 37s on a WT? I’m assuming 2”?

With 37s, do I REALLY need to be concerned about weight, etc. when adding a roof rack and cargo box after I receive the vehicle?

Lastly, if anyone thinks this is a really bad idea, please say so! I am trying to weed through a ton of decisions throughout this process, and I could certainly use some help along the way.

Thanks so much!!
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Toccoa

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37s are never a bad idea. ?
 
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DEADBIRDS

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Thanks! Can you elaborate as to why? Just curious if there’s really a huge difference between 35s and 37s when it comes to height and cargo.
 

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The Bronco marketing show model, the yellow one, lifted with 37" tires and no engine has a Raptor rear end, all Marketing smoke and mirrors.

You will have to wait and see what the aftermarket comes up with, puck spacers or taller coilover shocks all around and maybe new A-arms.

Go to tiresize.com to see all tire dimensions.
 

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Thanks! Can you elaborate as to why? Just curious if there’s really a huge difference between 35s and 37s when it comes to height and cargo.
I wouldn't say it's a bad idea IF you remember that your center of gravity is a good bit higher and then drive accordingly (aka - don't think that you are in a sorry Lexus or something and try to take the right hand exit from the left lane at 85).
 

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Thanks! Can you elaborate as to why? Just curious if there’s really a huge difference between 35s and 37s when it comes to height and cargo.
When you increase the size of your tires it makes the vehicle easier to tip or roll. The 35s that come on the squatch are actually 34.5". I would step up to a true 35"x12.5" MT, which will give you a little height and width for a great look. Furthermore, based on the axles that are offered I would not put anything larger than 35s. If you want to go big, throw some Ultimate Dana 60s and you can roll on 40s all day long. Lastly, there is a reason the Warthog has been seen with beefier drivetrain....
 

Beachin 74

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When you increase the size of your tires it makes the vehicle easier to tip or roll. The 35s that come on the squatch are actually 34.5". I would step up to a true 35"x12.5" MT, which will give you a little height and width for a great look. Furthermore, based on the axles that are offered I would not put anything larger than 35s. If you want to go big, throw some Ultimate Dana 60s and you can roll on 40s all day long. Lastly, there is a reason the Warthog has been seen with beefier drivetrain....
The flotation tire sizes are not the actual tire sizes.
A "true" 35x12.5 MT (BF Goodrich KM-3) is actually 34.5" tall compared to 34.4" tall for the 315/70-17 also and a little less width (almost 1/4") than the 315/70 17.

35x12.50R17/E 121Q
55079
Mileage Warranty

Section Width on Measuring Rim Width
12.50" on 10.00"
Eco Feature

Tread Feature

Overall Diameter
34.5
Max Load, Single (LB @ PSI)
3195 @ 75
Sidewall
Raised Black Letters
Revs/MI
602
Tire Weight
74.25

LT315/70R17/E 121Q
69713
Mileage Warranty

Section Width on Measuring Rim Width
12.70" on 9.50"
Eco Feature

Tread Feature

Overall Diameter
34.4
Max Load, Single (LB @ PSI)
3195 @ 75
Sidewall
Raised Black Letters
Revs/MI
604
Tire Weight
73.55
 

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The flotation tire sizes are not the actual tire sizes.
A "true" 35x12.5 MT (BF Goodrich KM-3) is actually 34.5" tall compared to 34.4" tall for the 315/70-17 also and a little less width (almost 1/4") than the 315/70 17.

35x12.50R17/E 121Q
55079
Mileage Warranty

Section Width on Measuring Rim Width
12.50" on 10.00"
Eco Feature

Tread Feature

Overall Diameter
34.5
Max Load, Single (LB @ PSI)
3195 @ 75
Sidewall
Raised Black Letters
Revs/MI
602
Tire Weight
74.25

LT315/70R17/E 121Q
69713
Mileage Warranty

Section Width on Measuring Rim Width
12.70" on 9.50"
Eco Feature

Tread Feature

Overall Diameter
34.4
Max Load, Single (LB @ PSI)
3195 @ 75
Sidewall
Raised Black Letters
Revs/MI
604
Tire Weight
73.55
Thank you for posting your information, but in reality most tires are not true to size, but what I am saying is get 35 x 12.5" tires. The Bronco will come with 34.5" tires and not 35s". I want true sized tires.
 

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Thank you for posting your information, but in reality most tires are not true to size, but what I am saying is get 35 x 12.5" tires. The Bronco will come with 34.5" tires and not 35s". I want true sized tires.
35x12.50 doesn’t make it true to size. This completely depends on the manufacturer of the tire. My 37’s don’t measure anywhere new 37”. Most seem to measure close to 36” on the vehicle.

I just ran out to the garage and took some measurements. A half tread 37/12.50r17 Cooper STT pro measured about 36” dismounted. A tire with the same tread depth on the vehicle measured about 35.5”. A tire with about 1500 miles on it on the vehicle measured right at 36”. These are at 25psi on a 4800lb rig. Just because it says 35/37, doesn’t mean it’ll measure that. There are some manufacturers that measure true...not many though.
 

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35x12.50 doesn’t make it true to size. This completely depends on the manufacturer of the tire. My 37’s don’t measure anywhere new 37”. Most seem to measure close to 36” on the vehicle.

I just ran out to the garage and took some measurements. A half tread 37/12.50r17 Cooper STT pro measured about 36” dismounted. A tire with the same tread depth on the vehicle measured about 35.5”. A tire with about 1500 miles on it on the vehicle measured right at 36”. These are at 25psi on a 4800lb rig. Just because it says 35/37, doesn’t mean it’ll measure that. There are some manufacturers that measure true...not many though.
Hello, you guys are killing me; that is common knowledge. Following your logic, which I am very well versed in the "35s" Ford offers will be about 33.5" tall according to the above--yes I well aware and agree with you. I think you all missed my point.
 
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edgeflyer

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My Bronco II with 8" lift and 35" swampers was much more stable than stock. Just run aftermarket wheels with more offset. Best to get the Sasquatch package to get the rumored stiffer springs which will help body roll.
 

Drex

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Thanks! Can you elaborate as to why? Just curious if there’s really a huge difference between 35s and 37s when it comes to height and cargo.
The discussion of a moving moment point on a flexible suspension is well beyond the scope of this forum, however going from (true) 35's to 37's will increase your ride height one inch. It will slightly move your center of gravity upward, which can be compounded into a rolling force depending on what conditions (corners, inertia, and speed primarily) exist and what the suspension is doing at that instant of time.

Bottom line is under normal (on road) driving conditions, likely will feel close to stock. On more extreme turns/braking/acceleration, even with stability control, it will be increasingly twitchy the harder you push it and the ultimate limits will (probably) be lower than with the shorter sized tires. It is a very generalized relationship, like if your motorcycle stops in 150 feet from 100 MPH before and 154 feet after. No big deal...unless there is a cliff (or a parked semi) at 150 feet. Keep your heavy stuff as close to the floor as you can when you load it and don't drive like an asshat. That will help. Increased braking distance is probably the biggest worry you will have as far as safety with an emergency stop, not tipping over sideways or lengthwise.

Below is just an aside, no need to read further unless curious;


The math needed to show how much moving the CG might change the force acting on the suspension and limits of the tires and suspension would require supercomputer time to solve the matrix for the suspension movement and then plug in the center of gravity to figure the force and the limits of adhesion (it goes on like this forever, inertia of payload, blah blah blah) For anyone wanting to go down a rabbit hole;


https://interestingengineering.com/what-is-finite-element-analysis-and-how-does-it-work

It is sometimes far easier, cheaper, and accurate to build the damn thing and test it in some cases, although with computer advances, that subset gets smaller every year. I suspect that most vehicles from big manufacturers use FEA model first instead of prototypes. although I do seem to recall reports that the Bronco went with full size clay models before the computer work as it was faster for the initial design 'look'

I did a senior engineering project (more than 20 years ago) that the allowed us to use the (since replaced) supercomputer as our calculations on a simple four piece assembled bracket with force applied at a single point would take all the memory resources (we had to run at night) of the mainframe engineering computer and it would churn away for between three and five hours calculating. Sadly, it crashed every time, we were choking it to death, large matrix calculations are incredibly complex. We got permission to use the supercomputer at the University of Illinois (one hour of time, we used slightly over a half second as I recall) to run the calculations. It was the Cedar machine, I never found specs on it, but the 19 year old machine it replaced was half a billion operations per second and the one that replaced it 17 years later was 1.4 quadrillion operations per second. So it had to be pretty stout. So, literally; a moving suspension would need a modern supercomputer to process the math on stress propagation, flexing of hard parts, and so forth.
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