Power loss on 35s?

My truck is sitting on 22 inch wheels with some 35s and there is significant power loss. My question is, is there significant power loss if you keep stock 17 inch wheels and pair them with 35inch tires?

 

Weight plays a big factor overall. Try to see what your wheel/tire weight is and go from there. Maybe even consider a little narrower 35’s if you’re running 12.5’s to further help with the loss of power.

 

Wheel size has very little to do with power loss (other than the weight of the wheel). The diameter/width and composition of the tire will have more affect on your power loss. With an identical tire brand, a 35" tire on 22" wheels will be the same as a 35" tire on 17" wheels. However, if you went with a narrower, lighter tire, you might see an improvement.

 

i'm running 275/65/20's which is about a 34.5x11.2" tire and came from 285/55/20 which are about the same width but 33". its modestly different but nowhere near what i'd consider requiring regearing or anything like that. As mentioned above, weight is going to be a factor to pay attention to as well.

 

your engine has not lost power, you have lost mechanical leverage moving to a larger diameter tire. Tundras have 430 gears and 32 inch tires stock. Increase to 35 inch tires is similar to reducing the gearing, so with 35s it feels like driving a stock tundra with say, 3.50 gears. And as mentioned, weight of the wheels and tires has a huge impact and can be much heavier than the stock setup.

Many with 35s regear to 4.88 or 5.29 to bring back the performance.

 

Currently running 35s (heavy duratracs) on 17in wheels. On the low end you can sort feel a difference. Sometimes on the highway it hunts for gears a little bit depending on speed.

 

We would need to know how much the 22" wheel and tire package weighs vs a 17" wheel and tire package. Generally speaking a 22" wheel is going to be significantly heavier than a 17" wheel, and since aluminum alloy is heavier than rubber (by a lot) a 22" wheel and tire package is going to be heavier.

For example a quick search on Tirerack yields the following numbers:

BF Goodrich All Terrain T/A KO2 35"X12.5"X17" = 66lbs per tire.

BF Goodrich All Terrain T/A KO2 35"X12.5"X22" = 67lbs per tire.

Alpha Equipt "Command" 17" wheel = 26.7lbs per wheel.

Fuel Off-Road "Assault" 22" wheel = 51.9lbs per wheel.

So with that in mind a 17" wheel and tire package weighs 92.7lbs per wheel and tire. While a 22" wheel and tire package weighs 118.9lbs per wheel and tire package.

That's a significant difference in case you didn't know, 26.2lbs of unsprung rotational mass difference is HUGE when you figure that is 104.8lbs of extra rotational unsprung mass on the vehicle you can probably see why acceleration, braking, handling, fuel economy, and ride quality take it right in the ass. Rotational mass takes a ton more energy to get rolling, takes a lot more braking force to slow down, and change directions. Further that extra unsprung weight takes a lot more capacity to dampen motion up and down for the shock absorbers.

There's a reason automotive engineers often go to extreme lengths (depending on application) to reduce unsprung rotational mass on a vehicle.

Then you make it worse by increasing the diameter of that rotational mass, because you increase the leverage arm of that mass on the axis of that rotation. The heavier 22" wheel has more mass in the rim itself than a 17" wheel and it is further away from the axis of rotation increasing that undesirable leverage.

The moral of this story is that only stupid people voluntarily put 22" wheels and big heavy tires on a truck and expect the wheel and tire package to do anything useful or good.

Then there is the issue of reducing your wheel torque by increasing the diameter of your tire and decreasing the relative leverage of your axis of rotation over the tire, albeit not by a tremendous amount on jumping from a 32.1" to a 35" tire. It's within a few pound-feet of wheel torque of the stock tire diameter, but it is a bit less.

 

Think it would be possible to take a trd pro (2022) and move up from the 32.6" setup it has to a 35" with lightweight wheels (assume 8-10lb savings per wheel) and achieve the same fuel economy ?

 

Probably not.

You also have to factor in raising the truck increases aerodynamic inefficiencies. Plus the tires still have some mass, and moving that mass further from the axis of rotation still has an effect.

That said being careful about saving weight will help. I doubt you will find a wheel lighter than the stock forged BBS on the Pro that’s anywhere near as strong.

 

Ah that makes sense, thought I found a loophole for a second. I dont know what the strength comparison is like but I was looking at TE37XT, about 17-19lbs per wheel.

 

What he said! Regeared to 5.29 with the 37x13.5 on mine -brought the beast back...and then some! You could try a Pedal Commander to customize your throttle response so you don't perceive you are lagging so much. I felt like with the 37's I wanted the regear and not a bandaid...but I did keep the Pedal Commander, just to take the edge off a lil! After the regear the truck gets going with ease and can't imagine towing without the regear...but again running the 37's vs. 35's so my issue was more pronounced.

 

There is a little button called “Tow/Haul” push that.

 

Every time you get into the truck? That would get old

 

There are mods for auto on. But no I don’t think the “power loss” is significant enough. Point was, if OP is worried about it there is a $free.99 fix for that.
I’m on 35s and don’t think there is anything to worry about it, after the first day you don’t even feel the difference. But I’m on 18’s.

 

Could always do what them Supra guys do and swap out your turbos day 1.

 

Does anyone know the offset of the current wheels (SR5 off-road in particular) or point me to a thread with it?

the bolt pattern is 6 X 1.39 correct?…or am I off there too?

Really want to know if a SR5 off-road (with whatever offset it has) and a level kit like the new rough country at 1.75 will rub if I put on some 295/70/18s from my current 2.5 gen.

 

I have seen lots of photos of lifted 3rd gens with 35x12.5's and no modifications done to the plastics. The stock wheels I have no clue what the offset is, ideal offset for the new truck is 18-35mm

 

You sure about that? I thought all things being equal other than tire diameter, a larger tire lowers your gearing. Again, all things being equal, lower gearing will mean slower acceleration but more top speed if your limiting factor is transmission.

 

Or just do what I did, and fit a blower and call it a day. It’s waay faster now than it was before the lift and tires
Oh wait, is he talking about an actual 22’ or the truck in his profile?!?

 

That’s not going to change your gear ratio or make the tires lighter.

 

Agreed.

 

Yes, a 35” tire on 22” wheels is the same diameter as a 35” tire on 17” wheels. They will both equate to the same gearing. However, those 2 tire and wheel combinations will have different weights. I am not sure which combination weighs more, but the weight will affect acceleration, mpg, top speed, etc.

 

99% of the time the larger the wheel the heavier it is and a lot of times the larger diameter rim’s tire is heavier as well. Small wheels, big tire gang

 

@Coal Dragger is exactly right. When I was in school a teacher had this spinning wheel. It was like a record player that you could stand on with a weak electric motor. You hold a pair of 10lb weights, hold them against your chest and you spin fast. Hold them outward and your rotation slows down. It was entertaining that 20lbs was there no matter what, but moving it outward put strain on the motor.

A 22" wheel puts the barrel out further than a 17" wheel. The barrel is the heaviest part of the wheel. The further out the weight is pushed the harder it will be to get it spinning. Hard to know what kind of difference was made without knowing exactly what wheels and tires you picked.

In general, an OEM 17 will be much lighter than an aftermarket 22. When looking at two of the same kind of tire, both 35s but one is lower profile than the other, surprisingly there isn't a lot of weight difference. Much like with wheels, the bulk of the weight isn't in the sidewall but in the tread. A taller tire will slow you down by gearing, but the big wheels adding rotational mass are whats kicking your truck in the balls.

Will a 17" wheel take less of a hit? Yes. Is it worth the cost of selling your wheels/tires and going to stock wheels with new tires? Maybe not. If you choose to do it, go with a skinny 35.

 

The real question is what does the OP want out of his 35”s? Looks or actual performance off road.

If he just wants bling to impress low IQ chicks at the mall then by all means rock those 22” wheels on your wheel and tire combo. It’s going to have a look that fits in with a flat brim hat, white framed sunglasses and a robot dick in the mouth (aka vape pen).

Otherwise go with the 17” wheel, the truck will perform a lot better and if you wheel it that sidewall height is gonna make life way easier soaking up abuse and not having issues like a low profile tire will.

 

You must regear your truck to counter the rotational drag from pushing larger tires! It will change your life! You can run 4.88 or 5.29. I went with nitro 5.29 after complaining of the same thing. Wow!’ What a difference it made. The truck is tuned to cruise at 1700rpm doing 65mph. I could even spin my tires and do some burnouts!

https://m.youtube.com/watch?v=mHAbztz5Irc&t=445s

Here is a simple conversation about the importance of regearing your truck after modification.