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I love my setup, 2017 F250 XLT 6.2 GAS (still 3.73s for now) 4 inch superlift with rancho 5000 shocks, forescan corrected speedo. (exactly perfect mpg) with no codes. 12 MPG city and 13-14 highway if i stick to speed limits. If i hit 75 mph then its 12 again.
TIRES mud terrain Coopers 37x12.50 on 17 inch rims (Next tires will be the pricier BFG All terrains because the MUDS are pretty loud especially the more they wear in)
Dual steering stabilizers up front and Tires FORCE balanced with Caster at 4.8-4.9 (drives beautiful, with almost no bump steer. )
The 3.73 ratio is way low but still tows and drives fine. I actually am a little hesitant to change ratios because most of my time is spent in the city at 45 mph which i get 13.5 mpg which i think is great for this setup.
Quality of Ride : very nice but could be softer with an adjustable shock like the Rancho 9000. I also keep my tires at 48-50 psi. (chalk tested and limit also changed in forescan for TPM)
Discount tire filled them up to stock 75 psi when new and it sucked. way too hard (Tire max was 50 anyways since it was a D rated tire)
another member has my exact setup with 4.88s and loves it but his mileage is in the 10s.
Agreed that there is an effect. However, I think the real question is whether the operator can perceive it. This largely depends on the use conditions by said operator.
Also, to be clear these trucks were designed for 34's (2017-2019's w/ 20's) and 35's (2020 w/ Tremor), so... there's that. It is not like jumping to 37's on a half ton.
That said, I have been battling this decision for a while now.
Yes and no. Although they are options, these trucks are tested and the posted performance numbers are based upon the smallest tire option which is the 245/75r17 which is 31.5" tall. Once you option up, your advertised numbers are no longer true as you are outside of those specifications as tested and listed. It is something that many do not take into consideration and the manufactures tend to not mention. Not only must you need to consider the height difference and effective gear ratio, the weight difference as you go up in tire size is what is what will cause the majority of extra stress on your front end (weight and rolling resistance). While the trucks are built stronger than you average 1/2, you will still notice a difference. And just to clarify In regard to the Tremor package, they are not true 35"s. They are a 285/75r18 which is a half inch off from the factory 275/65r20 placing it as a 34". The width and weight difference between those and a 35" is quite a bit.
Don't get me wrong, larger tires make these trucks stand out. However, it is a commitment when running 37"s and for many like myself, it's not practical for what I, or many others use it for. I'd say go for it but know that you will be sacrificing in other areas.
you forgot to mention anything about the negative wheel offset that most peole use. which puts the wheel and tire assembly further outboard of the ball joints and bearing. acting with more leverage on said components, like a cheater pipe on a wrench. increased driveline angles is another thing
people dont normally experience problems right away. so they figure theres no side affects of larger tires and lifts and offset wheels. but physics will always have the final word
Very true and those negative offset wheels are what add to hub bearings blowing early.
Yes and no. Although they are options, these trucks are tested and the posted performance numbers are based upon the smallest tire option which is the 245/75r17 which is 31.5" tall. Once you option up, your advertised numbers are no longer true as you are outside of those specifications as tested and listed.
As I stated in my first post, I'm not arguing whether the larger wheels and tires have an effect on performance. I agree, they do. However, it's just patently false to say these trucks were not designed for 34" tires. The tire size, 275/65R20 in my case, is listed explicitly on the towing guide and the door jam sticker. I thought the Tremor had a 295/65R20 option? Others would know better, but I do not believe GVWR or tow ratings are reduced. Regardless, even if they are reduced, by definition, the truck is designed (and specified) with those tire sizes in mind.
Now, the added weight of mud terrains could certainly be argued not be within design considerations of the engineers, as would 37's or aftermarket wheels with non-stock geometries. Again, though, the question is not whether these are statistically significant factors, but how practically significant they are. I suspect driving style and use conditions are the biggest factor affecting long term reliability and performance, followed by wheel offset, overall tire and wheel weight, and tire diameter.
For example, I'm considering the 295/65R20 Terra Grapplers on stock wheels. One of the main reasons for choosing the Terra Grapplers is that they are close enough in weight to the stock Michelins (61.3 lbs v. 57.9 lbs) that I expect this difference to be hardly noticable by me in terms of performance or reliability. I suspect, however, MT's or 37's would have effects I would notice and am not sure I could tolerate. I already know I'd need to make major upgrades to the suspension if I went w/ 37's, whereas I see those upgrades more as optional for the move to 295/65R20's. I love the way the truck handles and want to drive it till the wheels fall off...
If you want it, do it. Haters gonna hate!
I wouldn’t trade my setup for anything...
if you’ve got 31’s and wouldn’t trade Your setup for anything, I’m happy we can both be happy.
Hahaha, love it. Agreed.
No BETTER truck for 37's, that's for sure!
And every time I think I've made my mind up to be rationale and go with the 295/65R20's (for the time being, at least) your truck pops its head up and makes me question everything!
And every time I think I've made my mind up to be rationale and go with the 295/65R20's (for the time being, at least) your truck pops its head up and makes me question everything!
I had some anxiety about the 37’s from all the naysayers here. I even bought a set of factory wheels and had the 37s mounted separately so I could go back to OEM if I needed to chase gremlins.
Guess what? Not a single problem. I’m convinced most “problems” with 37’s are poorly installed lift or level kits that kill caster and introduce other problems.
the statements about unsprung weight, rotational forces etc are just factual. What the actual result of all of that is is not so clear. I tend to think the braking is the only thing that the physics are clear on... and I’m fine with the braking loaded and unloaded.
19 F350 6.7 with 3.55. Full Carli 4.5 pintop system with full rear leafs, airbags, PMF dual stabilizers, 37x13.5x20 Nitto Exo Graps with Wilwood brake upgrade. Just waiting on Carli torsion bar install and front Eaton Truetrac LSD to make it a more complete desert runner. Speedo corrected with Hypertech, pedal commander installed, 55 gallon tank.
1. Get about 14mpg in mixed city/highway. Towing my 9-10k trailer, get about 10mpg.
2. Don't notice any difference in towing handling-wise. It towed great before, tows great still. But I'm not hauling 30k goosenecks around.
3. The ride I feel is vastly superior to stock, but I've pretty much modded everything out with reputable components. I'm still waiting on Carli torsion bar install which should provide an even more supple ride. Overall more planted, more precise, more compliant with better control. Braking with the Wilwoods is seat of the pants better, but I don't have any metrics.
Will things wear out more quickly, potentially? Yes. That is the price we pay if we want to play. Granted, this is not a work truck, just a family and fun truck. This is also not a mall crawler, and is a blast to drive out in the sand... almost on par with the wife's Raptor - just different. Heavier truck, less nimble, slower steering, but still fun.
Go for the 37s. For some of us on here including myself, I think the truck looks right with the 37s. For those that don't like the look, that's fine too. Super Duty's are great trucks and look beautiful stock as well.
19 F350 6.7 with 3.55. Full Carli 4.5 pintop system with full rear leafs, airbags, PMF dual stabilizers, 37x13.5x20 Nitto Exo Graps with Wilwood brake upgrade. Just waiting on Carli torsion bar install and front Eaton Truetrac LSD to make it a more complete desert runner. Speedo corrected with Hypertech, pedal commander installed, 55 gallon tank.
1. Get about 14mpg in mixed city/highway. Towing my 9-10k trailer, get about 10mpg.
2. Don't notice any difference in towing handling-wise. It towed great before, tows great still. But I'm not hauling 30k goosenecks around.
3. The ride I feel is vastly superior to stock, but I've pretty much modded everything out with reputable components. I'm still waiting on Carli torsion bar install which should provide an even more supple ride. Overall more planted, more precise, more compliant with better control. Braking with the Wilwoods is seat of the pants better, but I don't have any metrics.
Will things wear out more quickly, potentially? Yes. That is the price we pay if we want to play. Granted, this is not a work truck, just a family and fun truck. This is also not a mall crawler, and is a blast to drive out in the sand... almost on par with the wife's Raptor - just different. Heavier truck, less nimble, slower steering, but still fun.
Go for the 37s. For some of us on here including myself, I think the truck looks right with the 37s. For those that don't like the look, that's fine too. Super Duty's are great trucks and look beautiful stock as well.
I think you’re the first set of willwoods on these I’ve heard about in the wild. Can you say more about them? Do you think they would fit in factory 20” wheels?
You still feel it with the 6.7L - the sheer added weight of the tire will affect any truck. 37’s side by side with 35’s are noticeably bigger. 37’s side by side an OEM tire are mammoth. You will notice it in both acceleration and braking. Side to side handling gets alittle sloppy too - just a product of the taller sidewall.
I don't notice a difference in anything from stock EXCEPT a softer ride.
I think you’re the first set of willwoods on these I’ve heard about in the wild. Can you say more about them? Do you think they would fit in factory 20” wheels?
Not sure. Probably would fit. I’ve got another Method 20” with a 35” in the spare compartment, (also thinking about the Carli Trophy hitch when it’s available to fit a full sized 37” spare.)
I have +18 Gear wheels and Nitto Terra Grapplers 37's. These tires are light, 10 to 15 lbs lighter than muds. I cannot notice any difference in drive-ability with this set up other than a littler more flex. I have the 6.7 and acceleration has not been negatively affected. The +18 sticks out just enough to offer a better look than stock but not enough to cause faster front end wear. My old set up was the 295/20 Ridge Grapplers.
