Why run a 35" Tire?

full pull

full pull

Sales&Support Valair Inc
Joined
Jan 12, 2009
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What are the advantages to running a 35 vs a 33?


Yes they come in wider sizes, but if it was about tread contact patch a dual wheel truck would almost always out pull a single wheel truck....
 
Didn't you run 35's back in the day? I would think they would give you a little more wheel speed if you have the power but could really hurt if you don't..If that makes any sense...
 
Ground speed is based off of wheel speed and traction. Gearing, traction, and engine rpm determine wheel speed. So explain how a 35 will give you more ground speed if all that is taken into account?
 
last time i checked duallys usually do beat singles.. just think of that in a clutch perspective...
 
One of the laws of physics perhaps, an object in motion tends to stay in motion. Meaning, more weight spinning the harder it is to stop. Just me guessing anyway.
 
full pull said:
What are the advantages to running a 35 vs a 33?


Yes they come in wider sizes, but if it was about tread contact patch a dual wheel truck would almost always out pull a single wheel truck....
Click to expand...

Bigger foot print on the ground = better traction
 
I think everyone is missing the obvious... a 35 inch tire has 2 inches (give or take) more tread on the diameter. This allows the tread to stay cleaner on a sticky track. Bigger tires clean out better. This may not matter in dry conditions, but on a tacky clay track, I have seen better results with a 35 over a 33.
 
If the truck will hook it will have more ground speed. The bigger tire will have a larger rolling circumference so with each revolution it will move the truck further along. Like PT said also, bigger foot print on the ground.
 
Bigger footprint on the ground. More ground speed if you have the power.
 
With a 35" tire going 50 mph will cover more ground then a 33" tire will. I came across that back when we had a pulling tractor. We did gain mph with a taller tire in the same gear. The sled operator kept track for us.
 
I think the poster is thinking more along the lines of 33" tire with 3.73, or 35" with 4.10.

They aren't exactly the same, but a decent comparison.
 
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Groundspeed can be changed with gearing. I agree with pt that the biggest reason is the footprint.
 
I think its a 2 part deal. 1st is footprint, and not just width. Your front to back footprint will be longer with 35's not much, but it is. Secondly with trucks running a set gear in the tranny, and the diffs ate geared to match, will out grow the final that 33's give them as hp increases. Sure you could change gears, but that may take you out of that 1:1 tranny gear, or be too big of a jump, where 35's might be just enough to make a difference. I don't see a huge difference in either one, however 35's will be marginally better for most, and when hundredths of a foot count do you want to be behind?
 
2001cummins said:
With a 35" tire going 50 mph will cover more ground then a 33" tire will. I came across that back when we had a pulling tractor. We did gain mph with a taller tire in the same gear. The sled operator kept track for us.
Click to expand...

Missing the point, obviously in the same gear the taller tire will cover more ground.


Smokingoat04 is making the most sense so far,same thing i was thinking. Using tire size to get the correct final drive if the next rp ratio was too big of a jump.

My thinking is still that there is no actual advantages to running a taller tire other than the final drive.
 
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Ok lets take a look a this senareo.

Nv4500 4th gear low range 4000rpm............... This will stay the same in both of the below cases.

4:56 ratio 33" tire wheel speed =31.6 mph
4:88 ratio 35" tire wheel speed =31.38 mph


Now tell me how the 35 is better.
 
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exactly...I know some of this will be a repeat, but to help others understand
33" tires with 1:1 gear in transmission and 2.72:1 transfercase
ex. 4.88 gears = 13.27 final 4.56 gears = 12.4 final however as horsepower increases you will out grow the final drive you are running especially in an 03-05 common rail or vp truck where you cant turn much over 4,000 rpms. Going to a 35" tire would net these numbers. ex. 4.88 gears, 33" tires, 4,000 rpms = 29.58 mph and 4.88 gears, 35" tires, 4,000 rpms = 31.38 mph a gain of 1.8 mph. Going to 4.56 gears while keeping 33" tires net 31.66 mph close to 35" tires and 4.88 gears. Tires are most of the time easier to change than gears to achieve he same thing. Also the 4.88 gears will help the driveline releve some stress over a taller gear set. I think 35's are also popular due to that being the maximum height in some organizations.
 
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