Moving to 35s - what causes the most change - diameter OR weight?

dcmdon

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With the 8spd auto, definitely weight. The trans can do an amazing job in making up for the change in effective gearing, but it just takes more power to get heavier tires moving. Look for light wheel/tires, unless you're planning to re-gear. This will help with ride, too.
One way to look at it is that it takes more power to GET heavier tires moving. (Accelerate).

And it takes more power to KEEP bigger tires moving. (Steady state)

Weight impacts acceleration and deceleration. Size impacts steady state resistance. Generally speaking.
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Jeeperjamie

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Also we do not need load range E tires.

My 35 KO2s are C rated, saves a ton of weight.
Actually in the 315 70 17 BFG ko2 the e-rated ones are a half pound lighter than the C rated ones and I didn't think they made the 35 12.5 17 in a C rated tire.
 
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vh5150

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Actually in the 315 70 17 BFG ko2 the e-rated ones are a half pound lighter than the C rated ones and I didn't think they made the 35 12.5 17 in a C rated tire.
Yeah that is correct, they make a C rated KO2 in that size. This thread just helped me finally make a decision. I called my dealership and going with KO2 C rated 315/70s and teraflex and daystar. Excited and nervous. We'll see if a gear change then comes into the equation in the future. :)
 

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Weight, diameter and tread pattern all have a factor.

I had 255/75-17 BFG KM2s on my Willys a 32". I switched to 285/70-17 which is almost 33". The KM2s weighed 2lbs more each and had a more aggressive tread pattern. I actually gained 2mpg in the switch.
 

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Yeah that is correct, they make a C rated KO2 in that size. This thread just helped me finally make a decision. I called my dealership and going with KO2 C rated 315/70s and teraflex and daystar. Excited and nervous. We'll see if a gear change then comes into the equation in the future. :)
If you got 3:73 gears then you may want to. I got 4.10 gears on my max tow and was able to get 18.2-18.5 average. Once got right at 20 on a 4hr trip. That's with 315 70 17 BFG KO2s. I'm running 37 12.5 17 Kanati Trail Hogs now and am getting between 17.2-17.5 mpgs and we got 18.1 on our trip to the beach 2 weeks ago

Heres a few videos for reference

315 70 17 BFG KO2s


37 12.5 17 Goodyear MTR's
 
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vh5150

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If you got 3:73 gears then you may want to. I got 4.10 gears on my max tow and was able to get 18.2-18.5 average. Once got right at 20 on a 4hr trip. That's with 315 70 17 BFG KO2s. I'm running 37 12.5 17 Kanati Trail Hogs now and am getting between 17.2-17.5 mpgs and we got 18.1 on our trip to the beach 2 weeks ago

Heres a few videos for reference

315 70 17 BFG KO2s


37 12.5 17 Goodyear MTR's
Thanks!
 

colindo

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In my opinion, weight. But ALSO where that weight is! Meaning two different size tires that weigh the same will have different impacts due to the weight being further out.

The weight concern is what drove me to a C rated 35x11.50x17 on the stock, lightweight, alloy wheels. It's a pretty light package for a 35 (Tire = 63lb, wheel = 22lb).
What tires are you running?
 

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Hi all - how much of the changes attributed to moving to 35s is actually due to the diameter of the tire? I've researched a ton and as you all already know weight is a common & major part of the discussion. That said, how much of the change in diameter causes things like sluggishness and drops in mpgs and overall drop in performance when staying on stock 3.73 gears?

The reason I ask is that, like many I continually go back and forth between going 33s to 35s, but even then some of the 33s I like are essentially the same weight of 35s, example being 285/70 Nitto Ridge Grapplers compared to a BFG KO2 315/70 C rated give or take a pound or two.
Both.

The diameter increases leverage against the driveline. The weight increases power demand for the same action. Both of them kill efficiency, braking distance, and acceleration.

Over the last few decades what I've noticed is that the biggest hit comes from going away from stock tires to aftermarket tires. Significant bump in weight and leverage there. But after that the changes from 33 to 35 are small.
 
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vh5150

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Both.

The diameter increases leverage against the driveline. The weight increases power demand for the same action. Both of them kill efficiency, braking distance, and acceleration.

Over the last few decades what I've noticed is that the biggest hit comes from going away from stock tires to aftermarket tires. Significant bump in weight and leverage there. But after that the changes from 33 to 35 are small.
Looks like I'll be adding 19 lbs per corner. Hoping this isn't too crazy.
 

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Next time im getting C or D tires. My tire shop argued with me that 35s only come in E.
 
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vh5150

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Next time im getting C or D tires. My tire shop argued with me that 35s only come in E.
I am hoping to have the tires mounted in the next week, I'll post an update once I 've had a few days on them.
 
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