Pizza Cutter tires...

[Swank Force One]

Skinny example. 235/85-16 Duratracs on stock wheels. Not a real big fan, would prefer wider. Not really enough width for a truck this big.

2015-10-13_06-58-51 by concealer404, on Flickr

2015-10-13_06-58-35 by concealer404, on Flickr

 

[mr_ed]

There was an article I read some years back, I think from Peterson's 4 Wheel Drive, where they did a pretty interesting breakdown on this subject. Along the lines of the first article linked in this thread; taller is generally beneficial (gas mileage excepted), wider only to a certain point. The author got into flotation factor, the rolling resistance, diameter, width, so on and so forth, but he applied it to a number of different vehicles that are popular with people for off roading. After plugging in the numbers (weight, horsepower, etc...), it was interesting to see that wider tires, while better in soft stuff in theory, weren't always better in reality. For example, he showed that you very quickly reach a point where the rolling resistance of a wider tire will increase faster than and negate the flotation factor, something that would definitely affect our Montys that aren't exactly rocking dirt drag race motors.

I'll have to dig around and see if I can find the article. Very informative, and just plain interesting.

Ed

 

[BOPOH]

pretty cool links - thanks for the info! I chose 33/12.5-15 for mostly muddy slippery creek beds terrain, not sure if greater width is better in my situation but i'm still very happy with this size on stock rims

 

[plh]

Skinny example. 235/85-16 Duratracs on stock wheels. Not a real big fan, would prefer wider. Not really enough width for a truck this big.

I agree with you. I put 235/85s on our '05 last year. Fill the wheel wells fine, but are really skinny and sit inboard too much to look good. Really should be 255/85. Ha - or 285/75

 

[Swank Force One]

I agree with you. I put 235/85s on our '05 last year. Fill the wheel wells fine, but are really skinny and sit inboard too much to look good. Really should be 255/85. Ha - or 285/75

Yep, and honestly they feel pretty weird for on-road use. I run that width or wider on our XJs, which are much smaller and lighter trucks. I'm not sure which i'm going to move to in Spring yet.

 

[Clawhammer]

Yep, and honestly they feel pretty weird for on-road use. I run that width or wider on our XJs, which are much smaller and lighter trucks. I'm not sure which i'm going to move to in Spring yet.

Hmm, I'd been considering a set of 235/85's for my Tacoma but now you've got my second-guessing myself. I've got 265/75's on there now and they rub the frame with the wheel cut all the way.

 

[jeep-N-montero]

I agree with you. I put 235/85s on our '05 last year. Fill the wheel wells fine, but are really skinny and sit inboard too much to look good. Really should be 255/85. Ha - or 285/75

But you also get better mpg with the tires actually sitting inboard, much better than if they stick out from the fenderwell.

 

[Swank Force One]

Hmm, I'd been considering a set of 235/85's for my Tacoma but now you've got my second-guessing myself. I've got 265/75's on there now and they rub the frame with the wheel cut all the way.

Probably fine on the lighter Taco. I run/ran 235/75-15 on my XJ and it was great.

It's not dangerous or anything on the Montero, but it's definitely affecting cornering ability. It's a Montero not a race car, but it still feels not great.

 

[Swank Force One]

But you also get better mpg with the tires actually sitting inboard, much better than if they stick out from the fenderwell.

I've gotten an average of 16mpg so far with the pizza cutters. Getting worse mpg will just mean that it's...still bad.

 

[jeep-N-montero]

There was an article I read some years back, I think from Peterson's 4 Wheel Drive, where they did a pretty interesting breakdown on this subject. Along the lines of the first article linked in this thread; taller is generally beneficial (gas mileage excepted), wider only to a certain point. The author got into flotation factor, the rolling resistance, diameter, width, so on and so forth, but he applied it to a number of different vehicles that are popular with people for off roading. After plugging in the numbers (weight, horsepower, etc...), it was interesting to see that wider tires, while better in soft stuff in theory, weren't always better in reality. For example, he showed that you very quickly reach a point where the rolling resistance of a wider tire will increase faster than and negate the flotation factor, something that would definitely affect our Montys that aren't exactly rocking dirt drag race motors.

I'll have to dig around and see if I can find the article. Very informative, and just plain interesting.

Ed

Yes, the smaller contact patch then the greater the amount of friction you will have at that point, in this case being traction between a tire and the ground. I used to run wider tires on rigs until I became educated on the subject, my diesel Chevy has 235/85's on it and the Monty has 33x10.50's, and the Jeep will be sold soon.

 

[jeep-N-montero]

Yep, and honestly they feel pretty weird for on-road use. I run that width or wider on our XJs, which are much smaller and lighter trucks. I'm not sure which i'm going to move to in Spring yet.

I run a set of 33x9.50 KO's in the winter and they do feel a bit weird the first few drives, but worth it.

 

[plh]

But you also get better mpg with the tires actually sitting inboard, much better than if they stick out from the fenderwell.

Gas mileage is no difference from the stock 265 in my experience, I (we) put 30K miles on the '05 with the 265s and about 20k miles on it with the 235s. Fuel type (real gas vs E10) and driving style makes more of a difference.

Don't think even 285s would be outside the fender lines.

 

[jeep-N-montero]

Gas mileage is no difference from the stock 265 in my experience, I (we) put 30K miles on the '05 with the 265s and about 20k miles on it with the 235s. Fuel type (real gas vs E10) and driving style makes more of a difference.

Don't think even 285s would be outside the fender lines.

Coefficient of drag is a law of physics we can't escape, this increases as you increase the friction surface of a vehicle beyond stock parameters.

 

[magoh76]

I ran 235/85 ST Maxx on my 01 and loved them. Found steering to be responsive - never felt unstable. They did great in all the terrain I encountered, including snow. Didn't notice a difference in mpgs though, and I would like to have had some wheel spacers just for looks.

Sent from my Note 3 using Tapatalk

 

[plh]

Coefficient of drag is a law of physics we can't escape, this increases as you increase the friction surface of a vehicle beyond stock parameters.

Can't disagree there, but there are many factors with various weightings (not all equal) that apply to gas mileage. My comment was focused on the fact that from my experience, other factors weigh higher than tire width.