FYI Michelin Primacy MXV4 Tires

Thanks for your report. I'm curious why you wanted the Harmony tire vs the MXV4? Is there much difference?

I too am looking at replacements for my OEMs on my 2006 and have looked at the MXV4 at our local Sams Club. They show the sale only until Sept 30, not Oct 31. Are you sure on the sale dates? Thanks!

 

Hope this helps somone make a decision. Seems like a reasonable choice plus the $60.00 back from Michelin. Call them and they will send you a coupon. You have to buy before Oct 31, 2008.

If you don't mind sharing, what was the total cost of your tires?

 

I could not stand the oem tires and did some research for replacements. According to Continental their new conti pro contact was supposed to have low rolling resistance and good traction. The MPG's went way down so I increased the air pressure, the ride was very rough - very disappointed (also lost a great deal of mpgs). I saw that costco had a sale on michelins and decided to check it out. I ended up purchasing costco's only michelins for sale (it appears that the name of the tire changes depending on where you purchase them). They gave me a sixy dollar coupon used in the store (which made the price of the tires $99 dollars each). After playing with tire pressure (now 42/40) the ride is excellent and the gas mileage is always 53 to 55 mpg (25 percent city and 75 highway - approx 70 miles per hour). I would Definitley recommend these michelins.

 

Which michelin tire did you purchase at Costco for your prius? I have a 2007 prius so I wonder if it's the same tire for mine?

The last time I checked with Costco they said they didn't carry the tire for my Prius so I had to go to an independent and it wasn't cheap, like $160 for one tire.

 

The Primacy is very quiet and provides a great ride BUT they are also much heavier than the stock tire, something like 25 lbs vs OEM 17 lbs. Very noticable during initial acceleration with about a 5mpg hit on fuel economy. I have them and like them but I wanted folks to understand that they come with a MPG hit.

I've tried: OEM, GY TripleTread, Falken and now Mich Primacy. (115K miles)

YMMV

 

Did you like the triple tread from GY ?
Thanx,
Carl

 

In the beginning I did. Great traction and handling when compared to the OEM tires. They were also very heavy though and provided a stiff ride quality that I didn't like. After they started to wear they also became very noisy. Too noisy in fact for me, especially with the MPG hit I was taking. The Primacy tire rides better and is very quiet with the weight really being the only downside (along with the cost).

Be aware that the Primacy and the TT I used were a 195/60 size.

 

It's been 2 weeks since Costco installed the Primacy tires to replace my worn out GY Integrities ($123/tire came out to total ~$450 due to $80 discount). Based on the positive reviews found here, I had them install 195/60/50. Being brand new, they instantly felt great in terms of noise & comfort compared to the shot OEM's w/36K miles.

What I expected happened immediately (and still happening)... the dreaded MPG hit. Fortunately, it's been a very minor hit of only 2-3 mpg (~5%). So instead of 49-50mpg, I'm averaging 46-47 over the last 2 tanks. I'm hoping it'll climb up another tick or two as they wear down little by little.

In terms of handling/stability compared to the Integrities based on seat of my pants data filtering/analysis, Yes, it's an improvement. I don't hear squealing/skidding on turns and it "wanders" a little less on SoCal freeways. The real test will not be known until many thousands of miles later to see how well the Primacy's hold up as they enter their middle age & golden years. So long as they last close to (perhaps beyond?) their 60K warranty and they provide better/safer feel than the OEM's, I'll be more than satisfied.

 

Your 5% MPG hit is not completely real. I can account for half of it with the change in revolutions per mile. First, the Primacy is rated at 851 revs/mile compared to the Integrity at 855. This changes your speedo/odo calibration by 0.5% which lowers your Apparent MPG by a like amount. Second, when a tire wears the revs/mile goes up due to a reduction in the tread thickness (this also slightly reduces rolling resistance) by about 0.25 inches at end of life. This reduction in circumference of 2% causes another false change in MPG by the same factor.

Another factor is that the temperature is now dropping which also reduces MPG so wait till you have a full year of data before trying to compare your new tires to the ones you took off.

When I replaced my Integrity tires with Michelin MXV4+, a detailed analysis showed a 0.5 MPG improvement (mostly due to better MPG in the winter). When I replaced them with my Nokian WR tires another MPG improvement occurred (about 1 MPG, but I have to wait one more month for a full year of data).

See the attached spreadsheet for details.

JeffD

 

This response is to answer VOSCOTT's question about the michelin tires.
The costco close to my house only offered the michelin x radial. It comes with an 80,000 mile warranty and a 60 dollar coupon to costco - it made the tires cost $99 each. Inflating the tires to 42/40 increased my mileage over the goodyears and had an enormous improvement in ride and handling(current mpg 53 -55 , includes some fairly large hills to climb to and from work).

 

I just replaced my Prius original tires with Michelin X's from Costco and my mileage has dropped by 4 MPG! My PSI is 42. Any thoughts?

 

What tire did you replace with the Michelin X's and how many miles where on them? Any new tire will have more rolling resistance than a used tire thus lower MPG's, it will take at least 500 miles to break a new tire in.. I would look on the sidewall of the tire and see what max PSI is for that particular tire and bump it up to that..Other than that give them some time and please keep us posted on the MPG's..

 

When you guys are replacing your tires, are you going into the menu on the MFD that has a button you select when you put new tires on your car? I thought (or perhaps I'm confusing this with another car) that in the instruction manual it said that if you put new tires on your car, you're supposed to make a section in your MFD. I wonder if that has an effect on the accuracy of the MFD mileage displayed?

 

duplicate deleted

 

not aware of any adjustments on MFD that can be made when changing tires

 

"

Thanks for your response. I'm really at a loss here. The originals I replaced were Goodyear Integrety's. I had over 37000 on them and they were very bare. I was getting 47-48.5 MPG with them. The MPH has decreased even more with the Michelin X's to around 40 MPG. The sidewall is 44. I've had them at 42. I haven't changed my driving at all. Is there something else that could be wrong? This happened immediately after I replaced the tires. I have run 3 tanks of gas and the performance is decreasing. Costco nitrogen and I had them reconfirm the PSI.
Thanks

 

Colder temps...

alignment + balancing?

tire breakin period not passed.