tires

[z71chev2345]

Hay guys whats up?

 

I was just wondering how big of tires i could fit under my stock 98 silverado z71 ext cab with out rubbin?

 

and, if i raise the torsion bars would that level out my truck and give me extra clerance? i have heard that it would but also puts more stress on it so if someone could help me out id appreciate it

[Shaners]

Welcome to the Forum.  I don't know about the old body style trucks, but the guys with the new body style trucks are putting a few turns in their torsion bars to level the truck, and that gives them enough clearance to run 285/75/16 tires.

 

Cranking the bars up will level the appearance of your truck, and will stiffen the ride a little.  It's not bad as long as you don't get too carried away.  I would recommend an alignment after you do this though...

[Archery]

I had been wondering about that...So if I adjust the torsion bars, I will be able to get rid of some of that tilt the Siverado's have that cause it to ride a little lower in the front...?  Is there anything else I need to do?

[Kansas Kid]

If I were in your position, I would look for a 255/85R16 tire.  They are a bit taller then 285/75R16 tires, but much narrower.  I for one am a fan of tall, skinny tires as they tend to handle most situations better then a wide tire.  Especially snow and mud.  Not to mention the 255/85R16 don't require you to crank on the torsion bars unless you simply want to level the front end.

 

But people who are into looks alone seem to like the wider tires.   :sarcasm:

[CMNTMXR81]

I think the stock size on the older half tons were P245/75-16.  At least that's what mine are on my 97 Tahoe.

 

As to whether wider is just for looks, I think you'll find that a wider with the same or lower profile sidewall will handle and perform better.  The only advantage to a tall skinny tire (other than looking goofy) is for load support.  But even still, those of us that have gone to the wider tires seem to not have lost any weight capacity.

 

For example, the stock LT245/75-16 Firestone Steeltex A/T's 10 ply load range "E" tire (a tall skinny, goofy looking tire) had a maximum load pressure of 3,042lbs @ 80psi

 

The LT285/75-16 BFG A/T's 8 ply load range "D" that I replaced the Firestone's with have a maximum load pressure of 3,305lbs @ 65psi.

 

To sum it up, despite the fact that I lose one load range and two plys, I seem to have more importantly gained an extra 263 lbs of maximum load and I can do it with 15 less psi.

 

So much for Kansas's "wider for looks" theory!

[Kansas Kid]

So much for Kansas's "wider for looks" theory!

Yep, you just shot holes clear through my theory.  You only mentioned better looks of a wide tire twice.   :sarcasm:

 

Just for comparison sakes to your load rating, if someone were truely concerned about that then the 285 is not your tire.  The 265/75R16 load range "E" is, with a 3042 lbs max load.  And being a load range "E" tire it is will reduce sway over a lesser tire, and can actually be overinflated to compensate for heavy loads.  But for some reason hardly anyone uses them....

 

As to whether wider is just for looks, I think you'll find that a wider with the same or lower profile sidewall will handle and perform better.

 

You must be talking about on-road performance only.  That and sand are where wide tires have the an advantage.  A tire with a lower profile sidewall is not a good thing on 4wd trucks, especially when they aren't used on pavement only.  If a short sidewall were the thing to have on trucks, all 4wd's would be running 20" rims and 50 series tires.  It is also pretty common knowledge that wide tires are not good in snow and ice, and only in specific situations better in mud.  (ever notice how those 2wd trucks with short wide tires are generally the first things to get stuck?) Wide tires also suck on gravel roads as they tend to cause the truck to wander.  Not to mention the increased wear caused by wide tires.

 

Just my opinion though.  But the majority of guys I know who really use their trucks do not like wide tires for the same reasons.

[CMNTMXR81]

Regardless of "sway" I can still load my BFG 285's with some 260+ extra pounds and do it at a lower pressure.  Arguing "sway" is like arguing coefficient of drag.  The difference of which is negligable between the two.  I fail to see how a 265 would be a better tire aside from the load range.  I'll live with my lowly "D" rated tires.

 

You must be talking about on-road performance only.  That and sand are where wide tires have the an advantage.

 

You don't say!  I wondered why I went from a LT245/75-16 to a LT285/75-16.  Hmmm, better off road AND better on road due to a wider footprint.  Granted yes I do have a little more sidewall but it's a stiff sidewall, so I can deal with it.

 

A tire with a lower profile sidewall is not a good thing on 4wd trucks, especially when they aren't used on pavement only.

 

 

285's are a lower profile tire than say a 245?  They're all a 75 series tire.  What that measure is, is 75% of the tread width.  As such, with a 245mm, 255mm or 265mm size tire, 75% of those sizes are respectively;

 

LT245 = 183.75mm

LT255 = 191.25mm

LT265 = 198.75mm  

 

LT285 = 213.75mm  

 

So how can you tell me my 285's are a lower profile tire?  That math they teach you in Kansas doesn't add up!

 

It is also pretty common knowledge that wide tires are not good in snow and ice, and only in specific situations better in mud.

 

Hmmm, seems as though my 285 equipped HD didn't have any problems out accelerating other HD's with stock 245's through the foot of snow we had here.  In theory I agree with you, but in reality I don't find that the case.  These things cut through snow like a hot knife through butter and compared to the LT245 Firestone's I had on there originally and in lesser snow, the BFG's outperformed them on all counts.  In most cases when "mudding" a wider tire generally performs better due to it's ability to "float" across.

 

Here are some hardcore numbers for you to compare and contrast.  I will do LT245, 265 and 285 all three will be 75 series and 16" wheels;

 

LT245/75-16

Sidewall: 7.234251968503937"

Radius: 15.234251968503937"

Diameter: 30.46850393700787"

Circum: 95.71962813437562"

RPM's/mile: 661.93320257212

 

LT265/75-16

Sidewall:7.8248031496063"

Radius: 15.8248031496063"

Diamter: 31.6496062992126"

Circum: 99.43017063861554"

RPM's/mile: 637.2311300790726

 

LT285/75-16

Sidewall: 8.415354330708661"

Radius: 16.415354330708661"

Diameter: 32.830708661417326"

Circum: 103.14071314285545"

RPM's/mile: 614.3063982138943

 

A LT285 a lower profile than a 265? I think not.  The LT285 is .590551181" taller in the sidewall alone.  Overall radius is the same.  Total circumferance for the LT285 is 3.710542504" larger than an LT265.  Hardly a low profile tire.

 

And like I said above, regardless of "sway" at maximum load, I can still add an extra 260+ pounds and do it at a lower pressure than those load range "E" tires.  I'll live with the "sway".

[Kansas Kid]

Well us guys from Kansas are pretty slow sometimes, and can't quite understand all that fancy talk.  But I believe the orginal comparison was 255/85 vs 285/75, so yes your tires are a lower profile then the tire I recommended.  As for the other stuff, I would hope as expensive as those BFG's are that they would be an all around better tire then the straight tread Firestones that came on the truck.  If not, you just wasted a good bit of money.

 

And with that said, I will just agree to disagree with you on this.  I don't have the time or patience to argue about this.  Maybe someone else will.

 

Heck, if gm-trucks.com ever has a get together and it includes a trail run, I just might end up pulling you out of the mud with my ugly little 255/85 tires.   ;)