Can't Buy Tires!

[More Power]

A scorching editorial will result from my experience yesterday when trying to buy a set of 265/75R16 Mich tires from CostCo.

In short, they refused to install a set of these tires on my 2001 GMC 2500HD D/A. :eek:

Reason given was that CostCo has had to pay for a couple of Allison transmissions because: 1- GM declines the drivetrain warranty if any size other than 245/75R16 tires are installed on the truck, and 2- a couple of real knothead D/A owners cheated (my opinion) CostCo into replacing their transmission - claiming the larger tire size caused a failure.

I don't blame CostCo.

MP

[ 06-08-2005, 09:34 AM: Message edited by: More Power ]

[zip]

Wow. And I just priced the same tires at Costco yesterday! I was wondering how they do in the snow and mud.
Decided to pay extra and buy thru a local dealer so I can get the free rotation etc. Costco is about 45 miles away.
Neither mentioned anything about what you've mentioned.Maybe the word's not out yet here. Good luck Jim.

[More Power]

I found another local tire dealer who will sell/install the LTX 265's. I was upfront with them concerning what vehicle the tires are for. They're a few dollars more, but the tire center is locally owned, so I don't feel too bad about it, plus they offer free balance/rotation for the life of the tires.

MP

[DmaxMaverick]

I found this out years ago about Costco. I bought the tires, and when I took the '01 in to have them installed, the gave my money back and said I couldn't have the tires.

The salesman did give me a hint, though. He said to just purchase the tires and carry them out. Costco won't install them (or even sell them if you use a vehicle that doesn't allow them), but will sell them if a vehicle that doesn't have restrictions is used. Problem is, you have to have someone else install them.

[OC_DMAX]

Is this a Costco corporate policy or just a local store policy?

Also, what size of tire do you currently have on your truck?


I am in the market for a new set of tires myself, was initially going with the LT265/75R16 LTX Michelins from Costco too. Then after the post on this forum about the Goodyear Wrangler Silent Armor tires, I have been researching that path. These Wrangler Silent Armor tires are offered in Load Range E LT265/75R16 size and have a substantially more aggressive thread than the LTX tire. Michelin, unforturnately, does not make their LT265/75R16 A/T tire in Load Range E.

[ 06-08-2005, 04:51 PM: Message edited by: OC_DMAX ]

[Turbo Al]

Up here in Canada Costco refused to sell me two tires for a 4x4 because they said it would destroy the trans. I would have to buy a set of four. I was also told to carry them out and put them on myself -- I declined and took my business to a tire shop.
Al

[More Power]

OC,

This is apparently a Costco corporate policy. The tire manager was quite well versed in the minutia of the D/A, GM warranty policy and the effect this had on Costco. I think it all stinks - especially the part about cheating a tire store.

The tire center I found that will install the tires told me everyone upsizes the tires on their D/A (the owner and his son each own one). My truck (and all 2500HD D/A's) came with 245/75R16's (Firestones in my case).

MP

[ 06-09-2005, 12:15 PM: Message edited by: More Power ]

[DieselEnvy]

I went through the same BS when I was shopping for tires for my girlfriend's Camaro........That time it was with Sears.

The whole Firestone/Ford Explorer thing I think is what got all these corporate stores in a tizzy......

Nowadays you've got to have some retired grandma who knows very little about cars, but just happens to work at a "Tire Center" lecture YOU, THE ENTHUSIAST, about tires!!

It just drives me crazy!

[More Power]

I've not seen a reason for GM's tire size policy, but I would assume the following:

1- A uniform tire size allows GM techs to have fewer variables to consider when troubleshooting customer driveability complaints.

2- A shorter tire maintains the rear wheel torque and power spec'ed for the powertrain.

3- A shorter tire improves roll stability and cornering.

Question: Is there a load carrying advantage for 245's?

Question: Why would GM install 265's on the SRW 3500's?

MP

[rjschoolcraft]

In general, the taller the tire sidewall, the less stable that tire will be laterally when heavily loaded. Things can be done to strengthen the sidewall when taller tires are desired, but it is not a one-for-one trade.

Have you ever noticed a "swimmy" feeling when hauling a very heavy load? That is directly related to side wall deflection in the lateral direction. (This is why performance tires for Corvettes, etc. use such low profile sidewalls.)

Duals are the main answer to this problem. You get twice the sidewall strength when compared to a single tire of similar footprint and sidewall height.

I would think that if a taller tire had an advertised load rating equivalent to a shorter tire (i.e. 265 vs. 245) that it would be OK. You might notice more instability, but the tire should be engineered to meet the load rating satisfactorily.

As for the 3500 SRW, are the 265's 75% sidewall height like the 245's?

I'll bet some of GM's warranty heartburn has to do with inaccurate speedometer readings after the change in size (if the VSSB is not changed). A taller tire will cause a lower mileage reading than actual, extending their warranty period. Just a thought.

[Jim Brzozowski]

MP, you'r on to something. While going through my manuals I found that GM diagnoses any and all vabrations by scaning frequency of vibration and of course its 2nd and 3rd order hormonics. If the tire size changes they then have no baseline data for number of rotations per mile to set up the ScanTool. I.E. they require stock tire size before they will even attempt to diagnose any kind of vibration complaint. That being said, It is incredible that any engineer or designer of a vehicle would be so narrow minded to design a transmission or suspension that would not be able to take whatever condition the typical enthustatically driven 4 wheel driver could or would put it in. If they're advertised to be the toughest, longest lasting trucks on the road, and they are advertised as such on TV all the time. Why doesn't GM step up to the plate and fix under warranty whatever is an obvious manufacturers defect. Otherwise the part wouldn't have failed. How long would it take them to put on a set of spec. wheels and tires to check out a vehicle at the dealership. Don't think it would be that expensive. American automobile manufactures and designers better wake up to the fact that they are not the only ones selling trucks and cars these days and proceed to overdesign just a little, that is to put a little more factor of safety in every calculation make. Make it just a little tougher than you think it needs to be. They aren't selling to the lowest bidder. People are willing to pay more to get more.

[RVC]

More Power

Question: Why would GM install 265's on the SRW 3500's?

GM went to 265's vs 245's for load capacity. The 265 are 3415 lbs vs 245 are 3042 lbs. On an E grade tire.

One upside to the 265 is it's a taller tire and lowers crusing engine rpm's.

[mcmonroe]

On average what is the difference in tire diameter or circumfernce between a 265 and a 245. These trucks really look better with the 265's. Just how much will the upgrade effect the sensors and whatnot?

Mark

[More Power]

The single rear wheel 3500's are factory equipped with 265/75R16's. Appearance is the only reason I can think of for upsizing the tire size on the ton'er. The only real difference between a 2500HD & an SRW 3500 is the rear spring packs - same engine, same transmission, same rear diff, same 3.73 gearing. Refusing warranty because owners install 265's on their 2500HD is difficult to understand.

The powertrain programming used in the 4500/5500 Duramax 6600/Allison 1000 medium-duty is dealer comfigurable for tire size and rear diff gearing. Would seem the folks at GM understand (on some level) that different owners have different needs or wants.

MP

[OC_DMAX]

The axle/tire capacities on our 2500HD trucks are:

front = 4670# (not tire limited)
rear = 6084# (tire limited)
total axle/tire capacity = 10754#
GVWR Rating = 9200#

So one can see there is margin in the GVWR rating (and probably a lot more than what is observable with the capacity ratings)

I believe the GVWR of the 3500 SRW is 9900# (correct me if I am wrong). So from just the numbers, MorePower is corect, there is no need to go to 265 tires. However, I suspect that GM wanted to maintain some additional margin (as is built into the 2500HD product line). Since I don't own a 3500 SRW, I am not sure what the door sticker says for the rear axle/tire capacity (though I suspect it is close to 6830#). The axle /tire capacity goes up by about 800 pounds and the GVWR goes up by 700#. So I believe the only reason GM went to 265's was due to the GVWR increase and to maintain the safety margin.

Besides, if they were worried about looks, they would have changed the tires for the entire 2500HD line (which sells a lot more units than the 3500 SRW).

[ 06-10-2005, 02:39 PM: Message edited by: OC_DMAX ]

[OC_DMAX]

Having said the above, look at GM's position today with its financial condition. This whole 245/265 tire situation is one very small symptom of why they are in the financial mess today.

Since the day these trucks came out, they should have been equipped with 265 tires. The 1 inch increase in diameter really fills the wheel well capacity (hard to believe, but until you sit two trucks side by side, one with 245's and one with 265, you do not realize the difference in looks).

Not only is GM is not giving the consumer what they likely want, but they are putting obstacles in the way for someone to make the changes themselves. Thats dumb. Companies always talk about customer focus, the customer is always right, etc,,, this is a classic example of what GM needs to improve upon.

[madmatt]

Being in a dealership, I understand GM's stance on warranty and tire size a little better because I see both sides. While most every owner here has good reason and since about themselves and their truck, for every one of you all, there is probably 5 people who would put 38's on their truck, then when a rear axle oo diff blows they'd come to us and say "well so and so has 285s on his truck and it didn't break". then they'd throw a fit about it and really not understand why. it's the retards like that that cause GM and other MFGs to be so "uptight" about warranty and aftermarket items. Dealer discretion has a lot to do w/ it as well.

[GaDixie]

I have never understood why GM puts those wimpy 245 tires on their trucks. I don't know of anyone who actually kept those tires, as they are useless off-road and look like spare tires. I have, however, not heard of GM refusing a warranty because someone put on larger tires, up to 305/75s. Most 3/4 and 1-ton GM trucks I know of actually run 285/75s.

[JD Diesel]

Ithink all the mfg put them cause they are cheaper? JD :eek:

[DmaxMaverick]

Originally posted by JD Diesel:
Ithink all the mfg put them cause they are cheaper? JD :eek: Contract bids. That's the only reason they go on OEM's.

Firestones are not cheaper than any other, apples for apples.

They are as good, or bad, as any other brand. It all depends on your use and needs. I know several folks that swear by them, and absolutely hate Michelins because they don't wear, fail, or whatever. Same goes for all brands.

The OEM Firestones I had on my '01 were fine, just too small. I prefer Bridgestone tires, and some would call foul on that. That's just my preference, and you're not changing my mind.

In spite of the Ford/Firestone issue, the tires, IMHO, were fine. It was just too easy to blame the tire. Firestone had fewer/lesser lawyers than Ford.

I know someone that has, and perhaps still will, buy the OEM Firestones take-offs, at a fair price, for such an inferior tire.

[JD Diesel]

Not cheaper in price mostly quality. last three truck that had them wore out about 25000. I am a maintance nut and always rotated them with the same results. True about the use last truck was a glass truck average about 7000 pound and more all the time. At tire change went to costco and ran the kirkland brand and averaged about 40000 to 50000 miles. until they stopped caring them. they where great tires. smile.gif

[More Power]

The Tires Editorial (http://www.thedieselpage.com/features/tires-editorial.htm) is now online...

Jim

[dcalex]

Hey Guys:
This is really confusing me. How does the truck know it's traveling one mile?...or how does it know it's traveling 65 mph?. One rotation of the wheel is one rotation of the wheel. If it has a smaller tire on it, it will actually travel less distance, but the truck doesn't know that. I can't figure out why GM would really care what size (within reason, of course) the tire is. If a truck had a larger tire on it and actually traveled a greater distance than smaller tires....who should care...the truck doesn't know it.....the rotations are the same; thus the wear & tear for warranty is the same. I would assume, without getting anal about it all, that if the difference between 245's & 265's is 3-4%; then one could expect a relative difference in delivered torque, actual distance traveled, as well as mpg. As has been said here, that's not much. Also witness the other brands/types of automobiles.....no paranoia that I've heard of. IMO someone at GM has got their shorts in a bunch because of the extremes that some guys go in tire sizes and lifts and rather than address it realistically, and put a realistic limit on what they will stand behind has just decided to satisfy their legal/liability dept.s by saying that no modifications period. Simple, sweet, and....... costing them the loyalty of the customers. I can tell you this.....if it weren't for Isuzu & Allison, GM wouldn't have a truck & I wouldn't have a GM....But what do I know. :confused:

[DA BIG ONE]

One only needs to look towards lawyers to find the reason. A trend in America of seeking civil remedy against those who change out oem tires to tires with lower than oem rating, then attributing that to the cause of the accident.

Example: OEM is "E" rated, and "C", or "D" rated tire was installed for looks, or other reason. The lawyers see a gold mine at the end of any action that can be attributed to lower rated tires.

Yes, some "D" rated tires, at a given tire pressure, can carry more of a load than some of the average "E" rated tires.

Then we get into the low profile tires on SUV's that simply can not carry the load. These days w/so many aftermarket wheels out there underrated wheels can bring a civil action upon the unsuspecting.

My Burb weighs almost 1,000 lbs more than my friends Burb w/gas rat motor (compared door stickers), so my burb requires the OEM HD riveted steel wheels, while the gas burb can use the weaker welded steel wheels. "These wheels look the same to the untrained person, but are very different in load capacity."

[oyazi]

Originally posted by dcalex:
Hey Guys:
.....if it weren't for Isuzu & Allison, GM wouldn't have a truck & I wouldn't have a GM....But what do I know. :confused: Sounds to me you know a lot ~ Outstanding quote. Wish I said it.

Fact was, I wasn't going to buy one until someone mentioned the eng wasn't GM design. That comment got me looking. Then the more I learned about the Allison swayed me.

Suspect many of the D**ge owners bought on the strength of Cummins eng ~ all in all, who's coming out better?

[Manfred]

I'm just dealing with OEM Firestone Steeltex failure at 23000 miles. Truck is 3 yrs old and rubber appears to have hardened out with cracks on the sidewalls and chunks of rubber breaking out on the running surface.
In the process I checked with Firestone, Costco and the local GMC dealer if tires could be upgraded to 265/75/16. Answer was yes. The dealership I quizzed specifically re. warranty and re-programming the Allison informed me that no warranty problem and no re-programming for the small change in tire diameter is required. I guess it depends who you talk to.
Plan to use Costco and forget about the warranty, since their offer and service/warranty is better at a lower price as Firestone, with a $350.00 warranty refund.
Having a GMC bumper to bumper warranty, I brought this to GMC's attention including my plan to upgrade. No negative comment sofar, awaiting a response on what good the tire warranty is, if there is no saving if tires faile prematurely.

[LJ]

Guys, I don't want to get negative again, so I won't- but I will draw to your attention another matter which doesn't appear to have been mentioned yet.

Did you know that the standard tires on my '03 Chev 1500 Z-71 were 265-75-16??? And now, just like you, my '05 2500 has the 245s. I can't tell you how many folks (even my daughters, who normally don't notice) have mentioned that "those tires don't look big enough for a truck that size..."

When you realize that you get stock 265s on 1500s and 3500s but not the 2500 in the middle, it makes even less sense than before.

[DmaxMaverick]

Those OEM 265's on your Z71 are C rated, and the 265's on the 3500 are E rated. Huge difference in the weight capacity.

You are correct in saying GM isn't making sense. Whatever their reason, they should consider the customer. If they offered the 265's as an option, they would probably sell more trucks. Just doesn't make sense.

[gritz]

One reason might be from www.allisontransmission.com (http://www.allisontransmission.com) FAQs:

Q. Speedometer / Tires - What effects will big tires have on transmission operation? A. The TCM calibration is based on factory tire size and rear axle ratio. Changing either of these parameters will have some adverse impact on transmission operation, including features like grade braking and shift stabilization. For instance, we have noted that when P285 tires are installed that the transmission generally does not shift to 5th range when towing heavy loads.

Puts the damper on what I wanted to do anyway.

[jcummins]

One reason might be from www.allisontransmission.com (http://www.allisontransmission.com) FAQs:

Q. Speedometer / Tires - What effects will big tires have on transmission operation? A. The TCM calibration is based on factory tire size and rear axle ratio. Changing either of these parameters will have some adverse impact on transmission operation, including features like grade braking and shift stabilization. For instance, we have noted that when P285 tires are installed that the transmission generally does not shift to 5th range when towing heavy loads.

Puts the damper on what I wanted to do anyway.


3500's has the Allison & 265's...do they have the same 3.73 rearends?

[Paintdude]

Originally posted by dcalex:
I can tell you this.....if it weren't for Isuzu & Allison, GM wouldn't have a truck & I wouldn't have a GM....But what do I know. :confused: This is why I bought the Duramax..Best truck I have owned to date....I am so glad I got a 02 post 9/11 built truck also..

[More Power]

Allison is generally correct about tire size affecting towing capacity. Anything that reduces rear wheel torque (like larger tires) can cause the transmission to stay in lower gears longer. Running with a max GCVWR and high wind drag load could also keep the transmission from going in 5th even with the 245's. This is why I think these trucks should have a 4.10 option.

All it would take is a discussion about tires in the owner's manual, along with a GCVWR chart with each tire size.

Jim

[rat4go]

I've heard that the reason the 3500 SRW can use the 265's is that it has the brake system to stop the bigger tires from turning at the GVWR of the 3500. I thought that the 2500 and the 3500 SRW brake system was the same, but if it's not, maybe it makes sense. The 1500 series trucks with factory 265's don't have a 9200+ GVWR (Closer to 7200 if I remember right) and the typical usage for a 1500 isn't as severe as what the 2500's were designed for, so maybe that explains why they can run taller tires with wimpier brakes.

I certainly agree that for a given speed/load, the taller tires increase the torque in the propshaft/trans/motor, and could limit gear availability, but this would probably be more likely in a gas motor than in a diesel. I'd think the higher torques in the driveline wouldn't be the issue in this case.

For me, running 285's, I mentally reduce the capacity of the truck (GVW or GCW) by about 7% to compensate for the taller tires.

Rich