Winter tires

phidauex

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Theoretically as long as the load rating is higher than the 1/2 of the larger of the two GAWR (gross axle weight rating), then you should be OK. However, manufacturers often seem to up-rate a bit, and I'm not sure what the methodology is for that (more safety factor? Accounting for aggressive driving? I'd be curious if anyone knows for sure).

For the Premium ER/AWD, the ratings are:
GVWR (Gross Vehicle Weight Rating)5800 lbs
Front GAWR (Gross Axle Weight Rating)2660 lbs
Rear GAWR (Gross Axle Weight Rating)3225 lbs

Half of the rear GAWR is 1612 lbs. The lowest load rating that exceeds 1612 lbs is "98", so "technically" anything over 98 should work, which may explain the demo cars on 99 rated tires.

That said, everywhere I've read suggests that you respect the OEM's decision on load rating (which on the door sticker is "103H") and not drop below it. But speaking for myself, if I found the tire I wanted and it was one or two steps below the OEM rating, but still well above the calculated rating, I'd feel OK going for it. Just do it eyes open.
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Theoretically as long as the load rating is higher than the 1/2 of the larger of the two GAWR (gross axle weight rating), then you should be OK. However, manufacturers often seem to up-rate a bit, and I'm not sure what the methodology is for that (more safety factor? Accounting for aggressive driving? I'd be curious if anyone knows for sure).

For the Premium ER/AWD, the ratings are:
GVWR (Gross Vehicle Weight Rating)5800 lbs
Front GAWR (Gross Axle Weight Rating)2660 lbs
Rear GAWR (Gross Axle Weight Rating)3225 lbs

Half of the rear GAWR is 1612 lbs. The lowest load rating that exceeds 1612 lbs is "98", so "technically" anything over 98 should work, which may explain the demo cars on 99 rated tires.

That said, everywhere I've read suggests that you respect the OEM's decision on load rating (which on the door sticker is "103H") and not drop below it. But speaking for myself, if I found the tire I wanted and it was one or two steps below the OEM rating, but still well above the calculated rating, I'd feel OK going for it. Just do it eyes open.
That is good to know.
So, a "100" rated tire, at 1764 lbs, will be greater than half of the 3225 maximum/GAWR rating, and would be OK.

Yes, I'm betting they went higher for a padded factor of safety.
 

SebastienMachE

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Theoretically as long as the load rating is higher than the 1/2 of the larger of the two GAWR (gross axle weight rating), then you should be OK. However, manufacturers often seem to up-rate a bit, and I'm not sure what the methodology is for that (more safety factor? Accounting for aggressive driving? I'd be curious if anyone knows for sure).

For the Premium ER/AWD, the ratings are:
GVWR (Gross Vehicle Weight Rating)5800 lbs
Front GAWR (Gross Axle Weight Rating)2660 lbs
Rear GAWR (Gross Axle Weight Rating)3225 lbs

Half of the rear GAWR is 1612 lbs. The lowest load rating that exceeds 1612 lbs is "98", so "technically" anything over 98 should work, which may explain the demo cars on 99 rated tires.

That said, everywhere I've read suggests that you respect the OEM's decision on load rating (which on the door sticker is "103H") and not drop below it. But speaking for myself, if I found the tire I wanted and it was one or two steps below the OEM rating, but still well above the calculated rating, I'd feel OK going for it. Just do it eyes open.
Food for thought: wouldn’t it be better for range if the tire is 103 instead of 99? Just asking., as my knowledge in this is very limited...
 

phidauex

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Food for thought: wouldn’t it be better for range if the tire is 103 instead of 99? Just asking., as my knowledge in this is very limited...
I think the answer is "it depends". The rolling resistance of a tire is extremely complicated, and is affected by everything about the design including the rubber compound, the sidewall construction, the lug shapes and depth, the hardness (durometer), air pressure, etc. And in all of these cases there isn't just a "more is better" relationship, higher air pressure for instance will improve rolling resistance for a while, until you get too high, and rolling resistance starts to increase again.

So maybe, for a tire of otherwise identical construction that was offered in both a 99 and a 103, the 103 might have better rolling resistance, but I don't think you can compare two different tires using the load range and guess at the rolling resistance difference between them.
 

Mike16

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But will the tire tread melt faster if you use 99 instead of 103?
 


phidauex

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But will the tire tread melt faster if you use 99 instead of 103?
No, the load rating doesn’t have anything to do with the tire compound or tread life, it is more about the sidewall, bead and belt construction. Higher load rating just means it can carry more weight, not that it will last longer.
 

phidauex

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FYI, for the load rating conversation, there appears to be two very similar versions of the Michelin Primacy A/S. The Primacy Tour A/S is 225/55/R19 99V and the Primacy A/S is 225/55/R19 103H XL.

So it does look like the pre-productions have the 103H, not the 99V shown on Tire Rack and elsewhere (which show the Primacy Tour not the Primacy). I'm still hoping to hear more about the stock tires people are actually seeing.

I believe the "XL" rating on the load rating means it gets a higher load rating at a higher pressure (41psi) rather than standard load (SL) which hits its max at 35psi. That makes some sense since the recommended pressure 39 psi, higher than most cars. That leads me to believe the XL rating isn't for weight, but for tire pressure.
 

kdryden99

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So do we know if our cars can have 2 sets of tpms sensors associated to it or does it need to be programmed if we switch wheels
 

generaltso

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So do we know if our cars can have 2 sets of tpms sensors associated to it or does it need to be programmed if we switch wheels
Modern Fords automatically learn new sensor IDs, so this shouldn’t be an issue.
 

kdryden99

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Modern Fords automatically learn new sensor IDs, so this shouldn’t be an issue.
So basically i can switch out the wheels with some universal tpms sensors and after a few minutes of driving itll get the new id's?
 

generaltso

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So basically i can switch out the wheels with some universal tpms sensors and after a few minutes of driving itll get the new id's?
The sensors will need to be the correct frequency, and compatible with the MME, but yes the sensor IDs will be learned by the car automatically.
 

generaltso

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How does the car react to teh absence of TPMS sensors?
Good question, I haven't tried. In some cars, US versions will continue to nag when TPMS sensors are missing, but Canadian versions only nag once since they're not required in Canada. Somebody will have to try it to see if that's the case with the MME.
 
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Considering the michelin pilot alpin 5 suv zp.. found it in 225/60R18

But I also see a michelin pilot alpin 5 in 235/50R19

I like the smaller diameter rim because $$$ but the other option seems like more grip.

So the big question, what is the significance of the "suv zp"? Both have the same load ratings and I haven't found the difference yet.

*Edit:. Okay I see "zp" means zero pressure, so I assume it has some benefits to allow it to run flat.

Not sure if I want or need that.
 
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With the calendar flipping to September next week and winters in upstate NY could start as early as mid-November, I am looking for Winter Tire advice. This thread has good advice on tire brands.

TireRack now lists the Ford Mustang Mach-E in their search. For winter tires, this link will show you the brands they carry: Mach-E Winter Tires

The list includes the Continental WINTERCONTACT TS 860 S for those interested.
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