33s power loss (Yes or no)

That's interesting. I have never ran any 255s, but I figured that because they are both close to 33" that they would feel about the same as 285s. They are usually about the same weights also.

 

I ran cooper discoverer st. Then run 48 pounds a tire. Overall they just rode better.

 

When I put 255s on my wife's truck it was a pretty drastic loss in power. But still worth it.

 

I have been torn on weather to get 32’s or 33’s ? I have a 2.7 so it will prob. Be an even bigger loss of power on my truck ....? Running 31’goodyear wranglers now ! I love them . Treads getting down to about a 35% tread left . Any advice ? Def. going with BFG KO2’s just torn on size ...

 

It’s all about weight. Like I said the cooler discoverer st is 48 pounds in a 255. Most 265/75s I’m seeing are around 55. So they’re a bit lighter. That’s not all 255s. Just those particular ones.

 

I got ya . Thanks for the info .

 

That is no joke. You will burn the clutch with 245/75/R16. These trucks have no extra power to give up on heavier or taller tires. I have the two wheel low kit to handle the reverse situation when needed. I have considered 235/85 to raise the gearing for highway use. I turn about 22-2300 rpm at 55 -60 mph with the 245/75s, that's bad enough. To me it's not worth the power or mileage loss with bigger tires unless you like driving often in 4th gear with the engine winding out. I left that behind years ago with 3 and 4 speed transmissions and 4:11 / 4:88 gears.

Of course, off road use is a different circumstance.

 

Interesting! Almost everyone speaks well of that tire size.

 

The only negative I’ve heard out of anyone is the looks. But I liked the way they looked more so than 285s.

 

Don't do it, man! Before I bought my stock V6 I drove a stock 2.7 and I really felt the difference in power. So, If the 4.0 becomes a turtle with bigger tires just think about the 2.7. Stay with the 31s and don't go any bigger. Unless you got the money for new gears!

 

Weight is very nearly meaningless. It has a very *slight* (marginal) impact on acceleration due to increased inertia, but like I said, marginal. Changing the radius of the wheel, however, that *will* make an enormous difference, because the reality is that vehicles are NOT pushed ahead by torque, they're pushed ahead by force, and while force is related to torque, it also accounts for the incredibly important radius that you need to convert that torque into force.

Force (pounds) = Torque (foot-pounds) / Radius (foot)
A 30 inch wheel has a radius of (30 / 12) / 2 = 1.250 feet
A 35 inch wheel has a radius of (35 / 12) / 2 = 1.458 feet

If you are making 200 footpounds and gearing it down by 16:1 in first gear, your wheels are being supplied with 200 * 16 = 3200 footpounds of torque.

Force on 30 inch wheel = 3200 / 1.250 = 2560 pounds.
Force on 35 inch wheel = 3200 / 1.458 = 2195 pounds.
2195 / 2560 * 100 = 85.7%
So increasing your wheel diameter from 30 inches to 35 inches will reduce the available force by over 14%.

Use the same calculations to compare any two wheel sizes. And don't sweat the weight -- reduce your cheeseburger intake by 1 per week and in a month, you'll make up the weight difference.

 

What he said!

 

Dude, go BIG or go home.

2.7 manual here - I didn't notice a difference with 32.5" ( 235/85/16 ) from stock..... but I've noticed a massive difference in 35s ( 315/75/16s ) - I honestly don't think 33 on a V6 would be a make or break, geared or not...... Plus the damn tire/ wheel combo weights so much - its tipping close to 100 lbs per wheel/tire.

 

Accepting the above as true-

Our torque peak is in the range of 220 ft-lbs at about 4000 rpm for the 4.0 V6. What have you got left at road rpm's of 2- 3000 when in 5th gear (1:1) let alone overdrive ? Dyno curves show about 100 ft-lbs at 2750 rpms, less at lower rpms...minus 14%..... That loss would be hard to ignore in the "useful" rpm range.

 

255/85/16 stock gears

Noticeable - Eh not really
Driveable - #racecar

 

for my driving style I notice it a little down low but not much. 285/75 ko2 on stock gears. I run about 2250 at 75 tho

 

When do you feel it more?

 

Any one else?

 

I bought my truck with 285/75/16's and it seems fine with the 2.7 AT in a regular cab. I had a Silverado reg cab with 35's and the 5.3 which had a lot of power, so anything with a 4 cyl feels weak compared to that. But I've been towing 2 different boats all summer and it's not really an issue. It will feel like a power loss but I don't think it's that big of a deal. It might also depend on what your normal daily driving situation is like. If you need to merge into traffic a lot, then it's probably not worth it since it could make your daily driving more difficult. If you live in a hilly area it might bother you there as well. If you can find someone near you with a set of 33's on rims, maybe you could try them out to see how you like it.