Leaving stock spare tire when upgarding to bigger tires.

[First Hummer]

I am just waiting for the post where one of you guys that have gone with bigger tires,but dont bother to upgrade spare and you get a flat.I understand is a money issue,but would you rather spend money on new tire or trany or worse new truck.Dont get me wrong the tires look great,but I am a firm believer of being prepared especially when off roading.

[First Hummer]

I am just waiting for the post where one of you guys that have gone with bigger tires,but dont bother to upgrade spare and you get a flat.I understand is a money issue,but would you rather spend money on new tire or trany or worse new truck.Dont get me wrong the tires look great,but I am a firm believer of being prepared especially when off roading.

[Desert Dan]

For short distances I wouldn't worry about it too much.

I would get the same size spare though for Off Road use.

With part time 4x4 I would have put the smaller spare tire in the front in a pinch to avoid diff issues. With full time 4x4 I am not sure?

[hispeed6]

If it were my truck then here is what I would do. First I'd buy 5 tires of the same size. Come on guys, if you can afford a $35,000 (average) truck then you can at least mod it with 5 tires instead of 4. Secondly, when you rotate the tires, do a 5 tire rotation instead of 4, keeping all 5 tires relatively the same wear-wise (and diameter-wise). Never understood why someone would have a perfectly good tire to use and not use it. Besides, with 5 tires the mileage is spread over 5 tires instead of 4, thereby making the entire set last longer.

Also I think using 5 of the same size tires is a good thing since I'm not sure how one smaller tire would affect the stabilitrack (autos only) or the traction control. Both I believe sense the delta between tire rotations across 4 wheels. One tire with a smaller diameter means one tire with a smaller circumference which will have to turn faster to cover the same ground. Also, if you have the locking rear diff it's a good idea to use two tires the same size so that one axle isn't doing all the work. This also applies to running same size tires at identical pressures to most closely match tire diameters.

Just my 2 cents, take it or leave it.

[HummerNewbie]

I agree and disagree with the affording a $35k truck thing. Not that it is the case with First Hummer but I am sure there a plenty of people that will be getting the H3 by stretching their budgets so the extra tire may not be an immediate option for then. Now if you are stretching your budget that much then you probably shouldn't be doing the mods anyway Now if you rotate all five tires, you are at least using all five that you paid for but wouldn't you then always have one tire that is slightly larger than the rest if only by a little bit?

As far as issues with the Stabilitrack or traction control, I don't think that would be a problem. Like Fox said, there would be a very negligible difference between the too. I am also sure that GM worked in a degree of tolerance between tires otherwise every vehicle with these options would have issue when one of the tires goes a little low the driver doesn't immediately notice and correct it.

As you said HiSpeed, just my 2 cents, take it or leave it

[Beastmaster]

Most open differentials will accomodate a maximum of 1" of actual tire diameter difference.

Limited slip diffs and mechanical lockers (Torsens and Detroit NoSlip Lockers, for example) will take up to 1/2" of tire difference. This is both from practical experience as well as from manufacturer specs. Detroit/Tractech says that for street vehicles with limited slips and Detroit Lockers, the tire needs to be within 1/4".

Anything more than that, the differential will heat up due to excessive wear. If it heats up too much, the diff will literally cook and then spew gear oil.

This is why rotation of your tires is paramount - keep the wear even across all your tires, including the spare.

[First Hummer]

I was more concerned with the much bigger tire difference rather than just the 1 inch.

[HummerNewbie]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by sfox:
Here's another question. If you manage to somehow squeeze 35's on an H3, where do you guys plan on putting the spare? and if it does go on a roof rack, what about the bracket on the back?

S </div></BLOCKQUOTE>

I was wondering the same thing. Doesn't look like there is much room to play with before hitting the bumper.

[Desert Dan]

Are you guys planning on running 35" for looks or ??

You might need to change the gears in the diff esp. with a 5 cylinder engine

If it could fit on the rear door will it support the weight of a 35" tire??

[bparker]

My stock tires and spare are 33" and so are my "upgrade" tires only the rim size is different.

So, no worries! =)

[timgco]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by sfox:
and if it does go on a roof rack, what about the bracket on the back?

S </div></BLOCKQUOTE>

...please stand by. Mods to come.