I would agree with Hokiefyd. We had the Primacy MXV4 as OEM (size P235/60/17) on our Toyota Sienna minivan. While I've been a fan of the Primacy MXV4 on other vehicles (had them with great results on a 2008 Honda Accord and 2010 Subaru Forester), these particular tires were down to 4/32 at 14,000 miles on the Sienna.
We replaced them with Bridgestone Dueler Ecopia 422s. We'll see how long these last.
Originally Posted By: Hokiefyd
Originally Posted By: barlowc
Based on visual inspection and the way that some of the siping has completely worn out, I don't see them last more than 40K.
With that said, it may not be the tire.
It probably IS the tire. In P235/60R17 size, the Primacy MXV4 is one of the OES tires for the Toyota Sienna minivan. Toyota specified certain design parameters and behaviors for the tires for their Sienna, and as with most OES tires, long life generally isn't one of the top priorities.
A key clue here is the UTQG treadwear rating. Look at the chart on Tire Rack:
http://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Primacy+MXV4
And click the "Specs" tab if it's not already showing. Notice how most sizes carry a treadwear score of 620? And notice how a fewer number of sizes carry a lower treadwear score of 500? These are often the OES tires--the ones with the lower treadwear score.
Most tire manufacturers offer the same tire warranty across the board on a tire model (like the Primacy MXV4). For this tire, it's 60,000 miles. Those who own one of the sizes with a 620 treadwear score are more likely to make the mileage warranty than those who own one of the sizes with a 500 treadwear score.