Michelin Primacy MXM4 Review

*Older thread that is more relevant here than in the GenII section*

I decided to junk my old Kumho Ecsta ASX tires and swap to a newer LRR tire from Michelin. My Kumhos were balding and becoming unsafe in wet weather. My new tire? The Michelin Primacy MXM4. It is a new tire even though the name may be confused with the Primacy MXV4. The new tire features a fairly high treadwear rating, excellent wet traction, and a decent price. It is designed for high end touring sedans like BMW and Mercedes but since I have 17" wheels it will work just fine for the Prius. The use of sunflower seed oil is a bonus for sustainability and for wet weather traction. For more on the use of sunflower seed oil click HERE. So I went from an orange peel oil tire (dB Super E-Spec) to a sunflower seed oil tire. Go organic! lol



Michelin Primacy MXM4 (Grand Touring All-Season)
UTQG=500 AA A, 51psi, 10/32, 21lbs, 844 $132

My initial impression of the MXM4 tires (215/45/17) is they are VERY quiet and smooth riding. I drove for the first day at the Prius manufacture pressure spec (35/33?) and the ride was very comfortable and quiet. Compared to my old tires these things felt like riding in a Cadillac! Handling was solid and the car didn't feel wishy washy like it usually does at these "low" pressures. My MPG did not seem to change much but I driven very few miles on the first day but I did notice that they seem to roll much easier when gliding.

Today, I aired the tires up to 50/48psi just to see how they compared to the Kumhos.

Noise: The MXM4 is much quieter on than my Kumhos (even when new) and are nearly equal or even quieter than my dB Super E-Spec (185/65/15) tires. Over smooth surfaces and rough surfaces the tire is very quiet. The only time I notice them is when hitting expansion joints or potholes and even then they are much quieter than the Kumhos and especially the dB Super E-Spec which pings pretty hard on expansion joints. The noise increases as pressure goes up. If you want a super smooth ride with very little tire noise I would suggest keeping them below 40psi. For most people concerned with max MPG I would suggest at least 44/42psi or higher. This is an excellent tire for folks who purchased the Prius V and want it to feel like a BMW.

*UPDATE* 05/25/2012 - Now that I have the 2012 GenIII I can compare these tires to the larger 195/65/15 AVID Ascend that I normally run. In terms of total decibels I feel these two tires are pretty darn close. I think the MXM4 is quieter in some cases and louder in others. To even compare to a quality 15" tire in terms of quietness really says a lot about the MXM4. Usually 17" tires are much louder.

Handling: The tires stick like glue. They are a little softer going into a corner than my worn Kumhos but they inspire much confidence when leaning hard and they made no fuss during the hard sweeping turns on various onramps. Keep in mind these tires are not broken in yet so traction should be less now than after break-in. Freeway attitude is smooth and the tires respond well to steering input. I will say that after airing them up to 50/48psi the car became more twitchy at freeway speeds. This condition requires more steering input that I don't particularly care for so after this test phase I will likely drop the pressure to the low 40s. I'll provide an update after a 1,000 miles or so.

Traction: It's rather hard to judge traction in a car that cannot spin the tires but in terms of lateral grip through corners the car is solid with nary a squeal when pressed hard into a corner. I have lowering springs on the car so I can take corners much faster than I could on stock springs yet these tires simply held without fuss.

Mileage: I cannot comment accurately on fuel mileage just yet because I still need to break the tires in and check my alignment. The hundred miles I drove today showed an increase of about 2mpg but this could easily be due to road conditions despite this being my usual commute. The tires do feel as if they roll much easier than the Kumhos though not nearly as easy as the dB Super E-Spec or the Nokian i3 but what do you expect from a larger, wider luxury tire? I'll drive my normal commute tomorrow and compare MPG numbers from Monday. I'll update MPG numbers after break-in.

*UPDATE* - The tires are listed as LRR but I do not think they are much better than my old Kumho ASX tires. My MPG is very similar to what I used to get on the Kumhos before they were very wore down. Compared to other non-LRR high performance tires they most likely roll much easier but they do not in any way compare to any of my 15" LRR tires.

*UPDATE* 05/25/2012 - I am testing these tires (with the same wheels) on my new 2012 Prius Three. So far the results are pretty good. The mpg difference between these 17" tires and my 15" AVID Ascend (T) 195/65/15 tires is fairly small. I am observing a 3mpg difference so far. This is a far cry from the 6-8mpg difference I was observing between this tire and the 185/65/15 dB Super E-Spec I ran on my GenII. So while I still feel this tire is not the best in terms of fuel efficiency, it is not as bad as I thought and is clearly a good choice as a quality replacement tire if you place an emphasis on quality of ride, quietness, long treadwear and outstanding wet traction. My last tank while driving conservatively in Eco Mode in my GenIII was 56.4mpg indicated.

Appearance: I'm not sure how I feel about the appearance of the tire. I know this is not a concern for some people but there are those who care about how a tire looks after they spent so much money on new wheels. The tire is nice-looking despite the tread pattern being rather boring when compared to something like Pirelii or Nitto tires. The MXM4s feature a very large "rim protector" if that is what it is. It is the largest I've seen and looks rather odd at first but when viewed from a distance it makes the tire appear thinner (aspect ratio smaller) so it is kind of cool. I'll let you guys decide. See pics below.

Price: The price of the MXM4 is comparable or less than a lot of other high performance tires. I paid $139/ea. at Costco. TireRack.com sells them for $132/ea. Because they are Michelin there is always a $70 rebate floating around. Costco takes care of the rebate for you. Total out the door was $607 for the tires plus mounting, balancing, environmental fee etc..

*UPDATE* - It appears the price for these tires has gone up quite a bit. They are often $150-$170/ea now.

Summary: Despite having driven just shy of 200 miles on these tires, I think I made a great choice and am enjoying the ride. As a bonus, the new tires now make my speedometer read accurately. No more 2mph off business. The confidence inspired by these tires is worth every penny. Especially after starting to hydroplane on my old tires during a freak thunderstorm yesterday.

*UPDATE* - With nearly 10,000 miles on the tires I can say I am very pleased with them and would purchase them again. There are no other tires in this size that I would even consider.

**UPDATE** I've had these tires twice now and I am always pleased with every aspect except fuel economy which is not terrible but it is not stellar either. The Continental PureContact offers better mpg and tire wear but are less comfortable and noisier. Still, if max mpg is not your primary concern it is hard to go wrong with this tire. We recently purchased a 2013 Acura RDX and this tire comes as standard equipment on this SUV. I'm equally impressed with the tires on this vehicle.

For more information on the tire and to see TireRack.com tests (video) click the links below.

Michelin Primacy MXM4

Testing New Grand Touring All-Season Tires