Costco is making a big deal about my 88H load index tires.

When my son got his Prius v tires from Costco they told him they needed to match the exact specifications of the factory tires for his VIN. Their liability insurance likely specifies that.

 

Costco seems to be sticklers when it comes to any deviation from oem specified equipment. They wouldn't sell me tires for my aftermarket wheels on a minivan even though I had the upgraded 17 inch size (16 inch oem) rims on the van. They said that even though a higher trim level of van came with the tires I wanted to buy, they only sell and service what originally came on the vehicle.

I suspect that your situation falls under the same situation, they'll only service or sell the manufacturer specified tires and ratings.

Posted via the PriusChat mobile app.

 

Goodyear tire centers had no problem selling and mounting tires on my aftermarket rims.

Posted via the PriusChat mobile app.

 

Tire load ratings are not added up for the entire car. Rather they must be checked for each axle. The max loads for each axle are posted on the placard in the driver door jam. You take the largest of these (for either the front or rear axle) and divide by 2. Your tire's load rating must be at or above this number.

 

If true about being sticklers IMO corporate guidelines have "come down the pipe" and department is following Costco rules.

Insurance/ Liability concerns would be the answer.

If not true, this Costco wants to upsell/ make sales or perhaps the department doesn't wish you as a customer.

Just guessing here to add to some thoughts to this thread.

 

Tell them to plow sand,

I generally mount my own tires so I don't have to worry about this nonsense.

 

Even with loose rims, they've always asked what the vehicle is, for me.

Our 2010 came with 215/45R17, and I'm hoping to swap over to 195/65R15 on PIP rims. It'll be loose rims, and I'd like them to also dismount the 17's and transfer over the TPMS sensors.

Right now all local Costco "warehouses" are not selling tires, due to snow tire installs. Maybe I better run this by them in advance, make sure they'll bless it...

 

Liability in a world of sue happy people. They are being smart. Most tire places follow the same.

 

No, these are not the numbers I am talking about. There is a black placard on the driver's door jam with white lettering. You want to find the portion that says GVWR (gross vehicle weight rating) and GAWR (gross axle weight rating). After GAWR, there is FR (front axle rating) and RR (rear axle rating). For my 2014 Gen 3, the values are 2,270 pounds for the front axle and 2,175 pounds for the rear axle. The larger is 2,270 for the front axle, and half that is 1,135 pounds. So your tires must be rated at 1,135 pounds or more. This equates to a tire load rating of 85, so I don't understand why Costco is arguing about 88 vs. 89 load ratings. Both are more than adequate for an axle with a rating of 2,270 pounds. But, it might be they are arguing about the size 185 vs. 195 instead.

 

Tell them it’s
1. A trailer
2. A 40/50’s era economy car

Then they won’t have it in their database.

Firestone mounted 185/65’s on my Cobalt to get their “sales price “
just had to sign a disclaimer stating I was installing the wrong size.

They said one size down was perfectly safe, larger they said is where they took issue.

 

It's no use arguing with them. Take the car somewhere else for a spin balance and rotation. And then do business elsewhere on your tires. Costco, in my experience, isn't very competitive on tires. Discount tires or Walmart are better at that. Tires on Pri's are important for fuel mileage, but not so much for speed and handling performance. My two gen 1's are right down there with the worst handling small cars that I've had. My ancient Dakota 4x4 does better.

 

The load-rating business is pretty complicated, as I went into some years ago here, and here, here, and here (the details in those posts were Gen 1-specific).

The carrying capacity of a tire depends on the pressure it is inflated to, and on two other things.

Which two other things it depends on will be determined by whether the tire size starts with a P or not.

If it starts with a P, the weight capacity depends on the size and load index, but not on the load range (SL or XL); in the P-metric system, SL/XL is redundant info that the size and load index already tell you.

If the size does not start with a P (it is in the different, Euro-metric system), the weight capacity depends on the load index and load range (SL/XL), but not on the size.

That's right, in the Euro-metric system, the same load-index number is the same weight capacity regardless of the tire size, while in the P-metric system, the same load-index number means different weight capacities for different tire sizes. But in the Euro-metric system you need to pay separate attention to the SL or XL (it changes what the load index means), and in P-metric you don't (given the size and load index, you know whether it's SL or XL).

The owners' manual for my US Gen 3 specifies a P-metric size and load index:



It's possible to put on similarly-sized Euro-metric (no P) tires, but that changes what the load index means, so it's important to look it up in the right place, and choose a Euro-metric tire with the right Euro-metric load index.

Euro-metric load index tables are published by the European Tire and Rim Technical Organization (ETRTO), and they are not too hard to find online, sometimes on the web sites of tire manufacturers like Continental that sell Euro-metric sizes.

P-metric load index tables are published by the Tire and Rim Association (TRA) in the "TRA Yearbook", and it is a lot more frustrating trying to find those online, but if there is a nearby engineering library, it probably has copies.

For a tire fitment to be approved, it has to meet two criteria. One is that the car's maximum rated load has to be less than the specified tire's capacity (at the specified pressure).

The other is that the car's normal load (calculated a specific way) has to be less than a certain fraction of the tire's capacity (at the specified pressure). The fraction is 94% according to the Federal Motor Vehicle Safety Standards. TRA advocates a more conservative 88% fraction.

I am reusing details from the earlier time I researched this stuff, which was 14 years ago. It's possible that some of the standards could have had revisions since then.

 

Complicated and on a Prius completely unimportant.

It’s unfortunate places selling tires do so just to sell more tires
by removing perfectly serviceable tires using hard and fast rules without understanding why.

Goid reason to have your own harbor freight tire changer at home.

Other option is to bring in the rims without the car

 

If? you had Costco road hazard on the tires that might be one reason (non matching car on the computer printout service invoice). The other is wear warranty with a lower spec tire since it's most likely going to wear faster than an 89 or 90 load spec tire. Just how much faster is anyones guess, and it just shows how a nit pickin tire mechanic can ruin a perfectly normal day.

I assumed you bought the tires in question from Costco by the wording and how I read the OP. I'm just hoping I didn't jump to the wrong conclusions by assuming and / or - reading wrongly - .

 

My Cobalt is going on 50,000 miles on a set of 185/65r15 ecopia (1st Gen) tires which I am told is extraordinary, I don’t know that slightly smaller makes a huge difference but in my case it’s working out.