So... I want larger tires to get more ground clearance. I have an 03 QS quadcab, 4x4 w/245-75-16 (stock?) tires. I would like it raised up some as it almost appears as though it's not even 4WD.

It's funny, when I bought this in Flagstaff (used, 29K miles), they didn't even have the owner's manual. They had a Cheyenne manual in it and I told them that this wasn't going to work... they ordered me a 03 Denali manual. The truck doesn't say Denali on it anywhere, but it has almost every option that the Denali book has. It must have been a special order vehicle.

So, back to the questions... are the 285's the way to go to get more clearance w/out buying new rims?

Also, what's the deal with turning bars? I am not sure what you are referring to... I grew up working on our cars and rebuilding engines, etc., but ever since the "new generation" of vehicles came out w/computer controlled garbage etc., the points, plugs, and condensors are a thing of the past.

Certainly I can adjust some rods though, if I knew what to do...

thx.


BTW, I have yet to see another QS on the road in Northern AZ, well, anywhere for that matter.... lots of 4x4s, but no 4X4-QS's...

Hey, Cat. The 285's will fit, but you'll definitely need to put a few cranks to the bars.

BUT- do not go too far with your 4x4- you can prematurely wear out the CVs. On 4x's, I don't recommend anything more than 2", and even that needs to be double checked. If it's slammed all the way down, then 2" is probably safe. If it's already cranked a little (which, by your description, it doesn't sound like they are, then 2" would be pushing it).

Looky here.

quote:

4x4- you can prematurely wear out the CVs. On 4x's, I don't recommend anything more than 2

You are such a help... I've been somewhat disapppointed with the look the vehicle has but knew that it was just a matter of time before I had it fixed. I'm also having some interior work done and will let you know the outcome of that when it's finished (they're taking out the center console, leaving my leather (heated) seats, adding the small center seat w/fold down arm rest (against the dealer's wishes), and I'll have to do something with the DVD controls and air vents on the back of the console and mount it somehow on the back of this center (20%) seat. We have a family of 6 and I need the extra seat, but don't want to give up the leather bucket seats up front...

My truck now has horrible ground clearance, so by what I read this morning, I probably have quite a bit to work with.

Thanks again for your support (and immediate response). These trucks are AWESOME!

I aim to please.

You aim, too, please.


(sign above the urinal !!)


Anytime, bud

Ok....just came back from a tire shop.... (Discount Tire). They said that tire manufactures will not allow them put a 285 tire on the factory rims (they are 6-1/2" wide/16"). Apparently some of those who have installed 285-75-16s on these factory rims are experincing uneven tire wear because they have put a wide tire on a narrow rim and the manufacturers say, "No more..."

That being said, he suggested going to a 255-85-16 tire which is slightly wider then the stock 245s, taller than the 285-75s and fit on the factory rims.

Apparently there are not many manufacturers that carry this size tire yet, but there are a few out there, one being the Goodyear Wrangler MTR. I dont' know if Bridgestone Revos do either in that size as the request is just now becoming more and more popular.

Thoughts?

I hate when they do that

Man, I got a bud here in town with 305's on his factory rims

GM did us a HUGE disfavor by making our rims so damn skinny See if they'll stick the 265 Revos on there. They're about 1.75" taller than stock, and are SUPREME tires all around.

Or... see if slipping them a $20 under the rug changes their minds !!!!

Or, find a different tire dealer.

I'd kinda say forget the 255/85.... they'll look like pizza cutters . Too tall and skinny.

I like MTRs, but they are a bit more agrresive than the Revos, and I bet a bit louder too (not that Revos are loud at all).

Let us know what you do

How do the Revos compare to the BF Goodrich All-Terrain?

Sears may do this for me... I don't have that much of a concern over the tire wear personally.

quote:

Originally posted by UofACat:
How do the Revos compare to the BF Goodrich All-Terrain?

Sears may do this for me... I don't have that much of a concern over the tire wear personally.

Can't really say- never tried the A/T's... I know the Revos have great ratings at TireRack, might look up the A/T's...

I've worn out 4 sets of BFG A/T's over the years. They are great tires. I've only have my Revos for maybe 10,000 miles but so far, I like them better than the BFGs. Can't go wrong with either one though.

Ok, an update of sorts...
Just came back from the dealer. They indicated that the michelin 285s will probably work w/out changing anything with the fenders (cutting out etc.) because they have "rounded" corners. This guy seems to know a lot about tires and options because that's what he does (service rep). The problem with other tires, like the BFGs ATs etc. are that they are somewhat "square" and the corners of the tires can rub while turning offroad (caster effects).

He recommends the LTX M-S in the 285s, try those and look at clearance issues within the fender well. The LTX A-T only go as large as 265. I'd rather have the ATs over the MSs, but the more reviews I reed on the Revos the less I believe they will be the best choice for the type of driving I'll be doing, a lot of road, but a lot of rocky driving, and the rocks seem to chew the Revo's up. I don't know how the MSs or the ATs will handle the rocks, but with the lug designs that the Revo's have, it looks reasonable that the lugs may grab or be "grabbed" by rocks and perhaps tear them up somewhat. If it was straight sand/snow/street driving, the Revos seem to excell, but with rocks they seem to have some wear/tearing/breaking lug issues. Perhaps not a lot, but it seems more then the Michelins do.

BTW, they have no problem with mounting 285s on stock rims, he believes that Discount Tire's "requirement" is them just trying to sell rims and it's a scam of sorts...

Regarding taking out the center console and putting in a fold-down seat (between the leather bucket/heated seats)... they can't do it because they would need to modify the seat slightly and he says that legal won't allow him to modify the seat brackets in any way due to liability issues. I'm going to do this myself. Apparently GM does not make this fold-down leather seat, only center consoles. I am also going to remove the electronics from the center console to maintain the DVD controls etc. for those in the back seat, plus re-direct the vent ducts back there too. This may take some work, but when I finish it I'll post a few pics. I need this center seat because I have 4 children and want to take the whole family out w/out doubling up on seat belts in the back. Maybe with the hole that will be left in the front panel (where the console comes out of) I'll mount a flat screen GPS or something... haven't decided yet...

They are also going to level the truck for free (raise it about an inch and a half) and will help w/re-programming for the tire size. He also mentioned some sort of programming (not GM) that will increase mileage/performance but was in a hurry and didn't understand exactly what he was referring to...

I'm also going to have them install an 8,000 LB Warn behind-the-(front)-bumper winch.


This truck seems to be a work-in-progress...


but you know...it sure is sweet to own & drive!



2003 GMC 1500 4WD Crew Cab (Denali/type options, although nowhere on the truck does it say "Denali"...) QS
Stock Tires (coming off soon!)
6.0L

Hi, Cat. On the tire question, I strongly endorse the Michelin LTX M/S, which has given me excellent results on several trucks and vans, and also wears tremendously well (for example, I just replaced a set on my van after 60,000 miles, and there was still plenty of tread). They are excellent highway tires (quiet, smooth, and crisp handling), but also do great work in snow or off road.

That said, I want to raise a caution about putting 285/75-16 tires on your stock rims. I know you've talked to various "experts", but suggest you check Michelin's own spec sheet (Michelin LTX M/S spec sheet).

Note that even for the stock 245/75-16 tires, the 6.5" rims GM stingily gave us are at the narrow end of the allowed range. For the 285s, Michelin (who do not sell rims, but do want you not to have premature sidewall failure or squirrely handling) requre rims a minimum of 7.5" wide and did their measurements on an 8" rim.

Meanwhile, from these specs, going to the 285/75-16s will give you about 1.1" of lift (half the difference in the diameters), and your gearing will get taller (speedo will read lower, torque at drive wheels will be less) by about 7%.

This message has been edited. Last edited by: Kong,

quote:

Originally posted by Kong:
Hi, Cat. On the tire question, I strongly endorse the Michelin LTX M/S, ...

Kong, so, are the M-S tires "better" than the A-Ts? My driving will be probably 30% off road, 30% snow/ice and 30% highway (living in Flagstaff, AZ). The M-S tires look a little like basic street tires... How they can do so well off road seems to me a little suspect. The A-Ts are at least "a little" more agressive than the M-S tires...

Also, did you have to cut out the fender well to allow the 285s? Also, what's the advantage of going to the 18" rims? Being a 3/4 ton you may have a little more clearance... but the fender wells may still have been an issue for you...

Good questions.

Between the M/S and the A/T, I agonized quite a bit and sought Michelin's counsel (their telephone support operation is very helpful as long as you don't ask about non-recommended fitments), chose the M/S, and have never looked back. I see lots of snow, but not many Rubicon-style rocky trails. Off-road for me means mud, forest trails, and the occasional stream bed. Yes, the M/S looks less snaggly, and is less competent in serious mud and rough rocks, but is more competent in all other respects, including snow. Your pavement time will be more pleasant and fun with the M/S.

My 285s are just about the same diameter as the stock tires, so I haven't explored vertical clearance issues. Horizontally, I can get a little buzz at full steering lock. The tread edge is lightly rubbing against something under there at full lock, and I should look for a shiny spot and perhaps do some trimming, but there is no issue in any other condition, including big bumps.

I went to 18" because I wanted wide, sporting tires (mine are rated for a sustained 130 mph; yee hah!) but didn't want to go "bling" or "monster truck". I like preserving the original gearing. The only tires that fit these requirements were low enough profile that they required 18" wheels. I could have pushed this approach further and gotten 20s, but I wanted to preserve enough sidewall height for protection against rocks, curbs, potholes, etc.

A fringe benefit of the 18" wheels is that they have room for bigger brake rotors, something I'm likely to apply in order to get more stopping power and less fade.

In your rock-intensive situation, taller sidewalls than mine are probably prudent, but the snaggly tires you probably want dont come in low aspect ratios, so I suspect that one way or another you'll be going to taller tires than stock.