Looking for Tire recommendations for my 2020 Prime

Yeah, being able to eliminate the TPMS worry by having a set of all-weather tires year around can be an attractive solution for some who don't require dedicated snow tires. I considered Nokian WG3 and WG4 purchases for my PP, but I could not find Nokian tires at a reasonable price at that time. They were very expensive even when compared to buying a set of rims and Xi-3. Now, I already have a set of extra rims, and since I like to do the tire rotation and other routine maintenance (oil and filter change if required) twice a year at the time of winter change-over, I will keep swapping tires and wheels twice a year. Well, I have to schedule my first 6mo/5Kmile free Toyota Care service soon. The last I checked, their service appointment was back-logged for 6 weeks.

 

It is recommended to rotate the tires though, and swapping in winter tires achieves the same thing.

Depending on regs in your area, and OCD level, just not having TPMS sensors on your winter tires does an end run around the debacle.

 

Before I bought an extra set of rims to go with dedicated snow tires on the 2017 PP, I always had snow tires changed over on the same set of OEM rims twice a year which was free at a local tire shop where I bought the tires. No worry about TPMS resetting. The only thing is that I was at the mercy of the tire shop schedule. If the first early storm is imminent and I can't make an appointment, then I would have to stay home during the storm. Before that when I was living in a big city, I never bothered with snow tires. They plowed roads very quickly and I almost never had a problem with non-winter-rated all-season tires year around. But after having dedicated snow tires on and driving on snow cover roads, there is no doubt that having dedicated snow tires on the snow-covered roads is a safer choice than not having snow tires.

 

Yeah there's no way I would go that route: twice yearly tire shop visits, and all the wear-and-tear on the alloy rims [shudder].

 

Winter tires are required from 1 December to 15 March in Quebec. The fines for not having them are VERY stiff (first time 300$ and double each subsequent time).

 

Most years I wait till somewhere mid-November to put on our snows. This year though, I've put them on already, at least a week back now. My logic: I don't like working in the cold*, and when you're driving the car maybe once a week, it doesn't make much difference, lol.

* Besides just swapping the wheels, I like to roll the pulled-off wheels slowly out the driveway, checking for and prying out embedded stuff, sponge bath and wax them, wax the chromed stock nuts, and so on.

 

Also, one thing to consider is road noise. I subscribe to Consumer Reports and they have detailed tire information in their latest issue.

 

That's the same rag that rated Porsche the second most reliable car made.....

 

FYI, if you need new tires, check out costco.com. I just ordered 4 Michelin Defenders and with mounting, balancing, and sales tax the total was $501. I was surprised at the low price considering inflation and that rubber is made from petroleum, etc. I decided to buy now rather than risk paying more later.

 

The correct tire for the Prius Prime is Dunlop Enasave 01 A/S 195/65R15 91S, 51 psi, 1356 lb, as it came with my 2021 Prius Prime. It is better than the Toyo tire that came with my 2020 Prius Prime.

Note that it is very easy to get the wrong tire, such a P-metric tire instead of a metric tire, wrong load rating, wrong pressure rating, etc. If you get the wrong tire, your alignment etc. will be off.

 

Until you wrote this, I didn't think there was a difference between P and non-P tires. Difference Between P Metric and Metric Tire Size - Consumer Reports

The tire placard on my 2017 Prime and 2013 Prius say P tires. However, I replaced them with metric designation tires. Consumers Reports says both tires are the same size and you can use either one, but don't mix them.

"Even within the industry, there are conflicting view points. To illustrate, let’s look at the differences between a P215/60R16 and 215/60R16 tire. Physically, they have about the same dimensions and appear to fit interchangeably, but you will notice a difference in the two- or three-digit number following the size called the load index. The higher the load index, the greater the load-carrying capacity of the tire. The P215/60R16 has a load index of 94, corresponding to a maximum load of 1,477 lbs at 35 psi; the 215/60R16 tire has a load index of 95 for a maximum of 1,521 lbs at 36 psi."

"Hence, if your car came with P-metric tires, you can replace them with P-metric or Metric tires. The Metric tire will have greater load capacity reserve than what came on the car as original equipment and is an acceptable substitute. A number of tire manufacturers allow for this substitution."

"Finally, don’t mix P-metric and Metric tires on a car as it could compromise handling, braking, and cornering performance."

I don't get it. They're both the same size, but the metric size has a higher load rating. Why would that "compromise handling, braking, and cornering performance?" I can't even find any P tires. The Toyota dealer, Big-O tires, and Costco all quoted me metric (non-P) tires for my car, even quoted as OEM tires by the Toyota dealer. Since my OEM tires have long been replaced, I don't know if they were P tires from the factory.

 

ISO-metric and P-metric tires have slightly different geometry and different load vs. pressure ratings. At the least, the pressure specs will change if you switch from one to the other. The alignment will probably be affected to. I would recommend against swapping P-metric with ISO-metric and vice versa, but if you do, you need to look up tire tables to remap the correct tire pressure from one standard to the other. The pressure on your tire placard will no longer be correct.

It is the industry (TRA (US), ETRTO (Europe), and JATMA (Japan)) that makes the load vs. pressure tables, not the tire manufacturers. It makes no difference if you have Michelin or Toyo as long as they have the same dimensions and of the same industry spec (such as P-metric or ISO-metric).

You can find the load vs. pressure tables and charts here. Note that P-metric (starting with a P prefix) and ISO-metric (no P prefix) have different load vs. pressure ratings; therefore, make sure that if your car came with ISO-metric tires, do not switch to P-metric tires and vice versa. For example Toyo Nanoenergy A41 is ISO-metric, whereas Toyo Nanoenergy A29 is P-metric, and they are not interchangeable. If you do decide to switch, make sure to remap the pressure from the original tire standard on the tire placard to the tire standard you are switching to using the tables below:

Find the correct tire inflation pressure | Toyo Tires

 

Some of the confusion may be due to the new tire rating system
https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/812325_2016-uniformtirequalitygrading.pdf

More might be from the old ways back in the dark ages of the last century when Europe and some other areas of the world measured wheels using millimeters, while the US measured wheels using inches.
If you ever tried to put a tire designed for a wheel measured in millimeters on a wheel measured in inches, the tire would not typically even mount on the wheel.

I'm not sure what the current logic has morphed into currently between the too.

 

See my previous post. ISO-metric and P-metric tire standards have different load vs. pressure tables. You at least need to remap the tire inflation pressures by looking at the tables if you change tire standards.

 

I had to look it up. But you are correct that the 2017 PP had a P-metric tire.

Here is the Tire and wheel spec from the 2017 PP owner's manual. And the photo of OEM Dunlop Enasave 01 A/S that came with my 2017 PP.




And this is from the 2021 PP owner's manual. And the photo of OEM Dunlop Enasave 01 A/S that came with my 2021 PP. Yep, the same brand and model of tire, but 2021 PP is 195/65R 15.



Now, I had to look at the size of my snow tires. Because I bought those tires for my 2017 PP 5 years ago. And at the time, I don't think I was specifically looking for P195/65R15 tires. As suspected, my winter tires are 195/65R15 not a P-metric. I don't think this tire (Michelline X-ice 3) came in P-metric size. As suggested in the CR article, substituting a P-metric tire with ISO-metric is OK, so that was fine on my 2017PP. Now using this snow tire on my 2021 PP is also fine since they are both ISO-metric sizes.

Here is the photo of my snow tire Micheline X-ice Xi3 195/65R 15 sizes used for both 2017 PP and 2021 PP. And as for using ISO-metric tires on my 2017 PP that came with P-metric size spec, I did not notice any difference in the handing or the way it drove. But I have to admit, I almost never inflated the tires OEM or not to the actual placard spec of 36/35. They were almost always over that psi, usually 38 in all four. So, I don't know how much difference it makes for real-life experience when P- and ISO- are interchanged as a set and not mixed on the car.

 

Even though the tire placards are different (P vs non-P), the tire pressures are the same. One would think there should be a difference.

 

I think the point is that at the same tire presser P-metric tire has a smaller load capacity. 2017 PP has 89 load index whereas at the same psi 2021 PP has 91. Now, I don't know if it is unsafe to use an 89S tire on 2021 PP. I don't think there is much difference in the weight of the car between those two models. But as you know 2017 PP was 4 seater whereas 2021 PP is 5 seater. That 1 extra seating capacity now requires a higher load capacity tire.

 

Can you help me understand the tire thing? How does it effect alignment?

 

If you don't set the pressure correctly, the alignment will be off. The pressure depends on the tire standard.

 

Sorry, which one? toe. camber. caster. thrust angle or all of them?