Flat tire

The Defender tread pattern (top), and the Premier tread pattern, below.



The Defender appears to have deeper and wider grooves? I think I understand why your tire has a longer treadwear rating. 80,000, compared to my 65,000. (Those are both 195-65R-15 size. The Premier just looks bigger in the photo).

 

Tire Tech Information - Uniform Tire Quality Grade (UTQG) Standards
--quote--
The UTQG Temperature Grade indicates the extent to which heat is generated and/or dissipated by a tire. If the tire is unable to dissipate the heat effectively or if the tire is unable to resist the destructive effects of heat buildup, its ability to run at high speeds is reduced. The grade is established by measuring a loaded tire's ability to operate at high speeds without failure by running an inflated test tire against a large diameter high-speed laboratory test wheel.

Temperature
Grades Speeds
in mph
A Over 115
B Between 100 to 115
C Between 85 to 100
--end quote--

Tirerack.com lists the specs for the tires they sell, and the 195/65R15 Michelin Defender T+H shows 10/32" tread depth vs. 8.5/32" for the Premier A/S. There's more to it than just tread depth. We don't know the characteristics of the different rubber compounds in the two lines of tires.

 

Yeah, defenders are around 10/32" tread depth, and premiers are 8.5/32". I think the premiers rely on the tread being more viable all the way down, with sipes actually opening up as the tire wears.

 

Here you go, Henri!
I was looking at a 2017 Prius, trim three, at the dealer today. I never thought I would see 18 inch wheels on a Prius.

Those are Continental "extreme contact" tires, 245-45R-18 mounted on TRD wheels. Obviously it's an accessory option. (It also had leather seats as an installed option.)
The tires have a 540 treadwear rating. AA Traction and A Temperature. Big wide grooves in the tread.

When I was shopping for tires, how did I miss those!?

 

With those larger wheels, the next improvement should be larger brakes.

 

We just got back from the trip :

https://drive.google.com/open?id=1xHF9v2dpDqkYzE939LNQDA07UR0&usp=sharing

Should have pictures linked into the map soon.

The Defender XT's did great. We averaged around 46 MPG calculated over the 3700 mile route. Seems good to me! This trip had a LOT of extreme grade mountain ascents/descents and high freeway speeds ( 80 MPH limit in some states). If you want to test your Prius....try this route! I should note that I was running the air pressure quite high ( 44/42 ). Even at at high pressure, the ride was surprisingly tolerable. Quite a bit more tolerable that the Ecopias we had on previously ( this is subjective..of course ).

Unfortunately, she burned quite a bit of oil. I'll post more about that in one of the "oil burn" threads. However, I noticed that most of the oil burn seemed to happen during the "extremes" of the mountain passes. That is, whenever the "power" mode was completely maxed out while going up...and "braking" mode was engaged while going down with a full battery. Even though I was ready for it, the "braking" mode engine whine is still very unnerving sometimes! I think I need a Prius Prime or the PIP...the larger battery sure would have helped with these mountain descents.

 

Me, who gets flats intermittently, never had a flat with my Toyo tires.

 

I bought nine used tires on larger than standard alloy wheel combos(no donuts) that have bolted onto my cars (no need for balancing)...... for a total $160 outlay. Looked so good, I had to get other tires/wheels for spares on my cars.

 

Only takes a drive past a poorly managed construction site to get a flat.

 

...even well managed ones.

 

That proves you have a mean sense of humor....... & so do I. ha ha ha.

 

Well ok then

Posted via the PriusChat mobile app.

 

For anyone reading post #104, DON"T ever mount a 245/45-18 tire to your Prius, they're overall diameter at 26.7" is
just too big.


Rob43

 

Yeah, on my 2013 Elantra, a 225x55x17 inch tire(same diameter as 245x45x18 inch tires) is too big, also. It intermittently scrapes the mudflaps when turned sharply, even with worn out treads. But, 215x55x17 inch tires will fit. & a 225x45x18 inch tire should fit on the Prius. But, have smaller wheels/tires so winter chains will clear the mudflaps & wheel wells.