Goodyear Comfortreds Ain't All That

Don't quite understand the question.

Any difference in RPMs between the OEM tires and the replacement tires will affect the speedometer/odometer/MPG readings.

Further, different model tires of ostensibly the same size can have different RPMs.

Finally, the different tire size calculators out there may assign different RPM values to ostensibly the same size tire.

As an example of all these differences, I believe that Goodyear or TireRack.com says that the 185/65/15 Integrity has 855 RPMs. But my favorite (and I think the most popular) tire size calculator -- the Miata Tire Size Calculator -- says that a 185/65/15 tire has 824 RPMs.

BTW, here's a link to the Miata Tire Size Calculator:

Tire size calculator

It's easy and good to use. But when getting replacement tires, whether they are the same or different size than the OEM's, you may also want to do the calculation on your own using the RPM numbers provided by the respective tire manufacturers.

 

Since I like answering the "tire" question I have actually saved an old post of mine and just modify it when the question comes up again, LOL.

My 2006 Prius was 2 years old on 3/28/08 and currently has 114,239 miles so yeah I drive A LOT.

My stock integreties lasted 76,480 miles and I ran them at 36 PSI the whole way around. One thing that is a must is to rotate them frequently and get a 4-Wheel Alignment check every 10-15,000 miles.

I rotate my tires every oil change at 5,000 miles and get my alignment checked every 3rd oil change. When you get you alignment check asked for the computer printout for your records. They usually show all four tires with something highlighted in red when it was out of alignment and now in green being in alignment. Without the printout you don't really know what was in and what was out.

If you keep these records and say your right front is always "out of alignment" it could be you hit a common pot hole on that side or something is wrong with the caster or something else with the tire. So, keep or at least look at your alignment records.

Now, why do you need to do alignment checks so often? No, I don't work for Toyota. Prii are setup to be as low profile and as aerodynamic as possible. Which translates into being very suspectible to being thrown out of alignment by hitting curbs, large pot holes, or other "bumps" in the road.

As a matter of fact you don't even have to hit anything to throw them out of alignment. When my fiancee bought her 2007 Prius Touring Edition I made them check the alignment on it and swap out the Integrities before we bought it. The car had 6 miles on it at the dealership and BOTH front tires were out of alignment.

We talked to a couple of people and they said "Yeah, it's a good idea to always to have any new car's alignment checked when you buy it. They have a tendency to get jerked around on the haulers. Especially the Prii."

Now, onto tires. After doing much research on this website, tirerack.com and others. I went with Michelin Harmony's and went up in size to the 195/60R over the stock 185/65R. I did notice a slight mileage hit but the tire is FAR superior to the stock in all aspects, will last FOREVER and is much much more stable in crosswinds because of the extra width.

On my finacee's touring edition, we had them also put on Michelin Harmony tires and upped them to the 205/60R size. Her Prius is even more stable than mine but has taken even more of a mileage hit. The Touring Editions simply can't run as well as the "Standard" Prius in my opinion. And she doesn't have as much practice maximizing fuel mileage as I do

I have to keep track of my mileage for work so know exactly that I have got 47.92 MPG over the first 99,000 miles. That has gotten better in the summer as it always does but I haven't done a mileage calculation since March to update it.

My fiancee's touring is averging around 45 MPG and again this is going up in the summer.

Well, that is my $0.02 worth. I hope it helps someone out there in Prii Land

 

Interesting that you mentioned the Harmonys. I have them on another car that I own and have found them to be very surefooted. Traction is very good on wet and dry surfaces and the tire runs very quietly also.

 

I've very impressed by how many miles you got out of the stock Integrities. However, I'm not sure I'd be willing to spend $600+ to double the life of a $200 set of tires.

 

How are the Michelins noisier? I was thinking about getting some. Thanks!

 

I'm not sure where the $600+ number comes from? A 4-Wheel alignment is only about $50 here and that is without using one of your handy dandy 10 or 20% off coupons from your book.

At 76,000 miles a check every 15,000 would be 5 checks at $50/check = $200. Seems like a lot less than $600? Confused there.

As an update on the Michelin Harmony's I've found they "hold" alignment a lot better than the Goodyear Integrities and I only need to do alignment checks about every 25,000 miles or sooner if it "feels" off.

The noise of the Harmony's may be a bit more on harsh roads than the Integrities were but not anything worth noticing. I still have 9,9,9 and 10/32 tread depths after 35,000 miles so expect these tires to be 100-150,000 mile tires.

Enjoy

 

Goodyear won't do a new tire swap for a wider tire, since a wider tire isn't in the Toyota specs. Is it worth upgrading the tire at the same size? I decided not to , based on advice from the Goodyear dealer. Especially not putting a lot of miles on the car. I'm satisfied with OE tire performance so far. I don't drive the Prius like a sports car, so it probably doesn't make that much difference. And the tire is rated all-season M & S, which means it will be adequate in cold weather without much snow. No sense in wasting money you are saving on gas mileage.

 

I used $60 for an alignment, which is actually about $10 less that I paid last month. 5 * $60 = $300 for the alignments. For the 15 tire rotations (every 5000 miles), I used $20 for a rotation, so 15*$20 = $300. $300 +$300 = $600.

But, if you can get free rotations, and reasonably cheap alignments, then it might be worth the extra bother, particularly on a $400 set of tires. But if you are spending more than $200 to double the life of $200 tires, you might as well skip all the extra expense and just buy tires twice as often.

 

No offense taken and I agree 100%. I am sure the kind of driving I do, highway, extended the life of the stock integrities but alignments are still a good call IMO. Since almost everytime I have ever done one something was out with the integrities. I never thought about it at the time but my guess now is they weren't balanced right. Since the new ones are there is less of a need for regular alignment checks.

I also agree with Marlin that 4-Wheel alignments can get pricey if you don't have free rotation and discounts. Since I caught caster wear damage and had to have after market adjustment bolts installed to get them back into spec on my old corolla I keep up on it now. Especially since Prii are so darn susecptible to being thrown out.

Again just my $0.02 from someone who has put A LOT of miles on cars over the years.

 

We just put comfort treads on about a month ago, and there is an improvement, BUT. I went in asking for the TripleTread, and Goodyear told us they were not available for the Prius.

Can you tell us the size and where you got them?

 

195 / 60 R 15 is the size I bought my Triple Treds in. They are just 10 MM wider then the stock OEM tires (same width as the touring) and the adjustment in the profile ratio goes from 65 to 60 to keep the speedometer as close to accurate as possible. Many big chain tire dealers will give you the run around with buying tires in the non OEM size. I bought mine from www.tirerack.com and then paid a local independent tire garage $50 to balance and install.

 

I had ConforTreds on my Intrepid. Didn't even last much past 20 K before I got Goodyear to prorate the change to a different model. Great at first but horrible after 1/4 of their lifespan??

I also had TT's on my Pruis. Tires were fantastic until they wore out at 40 K. I do drive aggressively (as can be done in my Prius) but on the highway, it's 65 in the slow lane. No reason they should have worn that quick. Plus they're expensive. Running Kumho Solus KR21 now. they were cheap and ride decent. I imagine i'll get 60 K out of these.

 

Goodyear was right in the sense that the TripleTred is not made in the Prius OEM 185/65/15 size.

Like I think almost everyone else who put TTs on their Prius, I put on size 195/60/15. I bought them from TireRack.com. I had them drop shipped to the cheapest approved local installer, who installed them for $15 each.

Good luck.