Tire Upgrade

Thanks PARK i have been looking around and i came across some info on the Michelin MXV4 , what i read is that the Mxv4 is a updated version of the Energy , which is a LLR tire , how is your mileage with this upgrade to the Michelin's ....?

Thanks

 

I recently replaced tires on my 2008 prius & went to 205/60R 15 tires. I typically run Michelin tires & was going to install the MXV4+ but there is a Kumho dealer approximatley 3 miles from my home, so I gave them a try. Impressive to say the least.

I lost mileage the first 1,000 - 1,500 miles but now seems back to where it was prior to the tire change, 47-50 mpg & cold weather.

The handling & ride is simply outstanding. The tire is also extremely quiet. The difference in braking is also significant. The tires have done well in wet, snow & ice. It basically makes the car feel like a totally different car. It is that impressive.

I have checked my speed with a Garmin GPS & if my speedo says 65, the gps says 64, so close enough. For PSI I run 42 front, 40 rear & there is no jarring, chatter or overly harsh feel. Like I said, it makes the Prius a different car & no negatives at all that I can see.

 

Hi wica,

Which Kumho tires were they?

 

Duh! Sorry about that. Kumho Solus KR 21

 

The speedometer may overread, but the odometer does not. If you can handle the information overload, go into the MFD's diagnostics and select Vehicle Signal Check. You will see your true speed reported in km/h. The speedometer overread is a deliberate fudge (by about 10%, on a UK car).

 

Whoa, I never knew that the overread was only in the speedometer. I had always assumed that all the different distance measurements (speedometer, odometer, trip odometer, fuel economy) were connected or sprung from the same source (factory fixed setting for tire rotation based on diameter of the OEM tires).

10% overread on the speedometer is a lot. I think that's the maximum allowed under United States and international standards/laws.

 

I recently purchased a used 2008 touring edition, it has about 10k miles on it and has Goodyear integrities in a 195/65R16 size. That seems pretty strange to me after doing some research about tires, I didn't know it was a touring until after I got it. I hate the tires and would like to change them. Should I go to a 205/55R16 to avoid run flat tires or should I stay at a 195? I'm really looking for better handling and stability out of it as living in LA necessities quick highway adjustments, etc.

 

The 205/60R15 tires have plenty of room, there is no contact or problems. The handling is excellent. Road handling/stability, braking, cornering, wet, dry. It feels like a totally different vehicle than the originals.

 

Odd that you have those tires on a supposed Touring Edition.

The Touring's OEM tire is the Bridgestone Turanza El-400 in the 195/55R16 size.

In any event, quite a few Touring owners have moved to the 205/55R16 size for the greater variety of tires offered, and I haven't heard of any problems.

If you haven't seen it already, here's a decent thread on tire upgrades for the Touring Edition:

http://priuschat.com/forums/prius-modifications/37637-touring-edition-tire-upgrade.html

There are other threads and posts on the subject too.

Good luck.

EDIT: If I had a Touring and wanted to stay with the OEM 195/55R16 size, I'd try the Falken Ziex. You can google "Falken Ziex" using the google search function here and get lots of posts about it.

 

I'm reading and see a lot of post regarding changing tire size.... , what is the real significance of the larger tire size , i do know with a up grade from the OEM Integreties , most tires of a better overall grade will give you increased , grip handling, smoother ride , longer tire wear , this is what i hear , my tire size is 185/65/15 , i have read some
owners have gone up from a this size to a 195 /60/15 on the same rim , my Prius is a base model not Touring, i called a dealer and asked if they would put the larger size on my car and they said either they would not do it , and did not recommend it , so my question other than , handling , longer tread wear , longer life , and appearance , what's the significance of the larger size

 

All other things being equal, changing to a wider width tire should result in better overall handling, traction and braking, but lower mpg.

For example, when Consumer Reports road tested the 2004 Standard Prius with its 185/65/15 Goodyear Integrities and a 2007 or 2008 Touring Edition with its 195/55/16 Bridgestone Turanza El-400s, it found that the Touring Edition had 10 feet dry and 12 feet wet shorter 60-0 mph braking distances, but also got 2 fewer mpg than the Standard Prius. I think that most of these differences are attributable to the 10mm wider Touring tires.

The Standard Prius' braking distances are below average. It ranked only in the 11th percentile of the over 100 current model sedans tested by Consumer Reports. That's pretty bad.

Personally, I think trading 2 mpg for 10-12 feet shorter braking distances is a very good trade. I switched to 195/60/15 Goodyear TripleTreds when I only had 1000 miles on my Prius and its OEM Integrities.

 

Thanks Boo, i have read alot of your post , and i do appreciate the time you put into your research , its greatly respected , from a new Prius owner such as myself , all points taken , as far as the MPG drop is concerned , is the drop a on going result from the upgrade , or does the MPG return after the break in period ?

 

The 2 mpg drop was what Consumer Reports reported. Because they test new cars, it was a 2 mpg drop from the Standard Prius' new tires and the Touring Edition's new tires. I doubt that this 2 mpg differential would change as both cars' tires wear.

It would be great if we could have a real apples to apples (different sizes of the same tire) comparison test. But I think Consumer Reports' results make sense. And that if you were to do a comparison test of 185mm wide Integrities against 195mm wide Integrities, you'd get substantially similar results.

If you do decide to go with 195/60/15 tires, a lot of places (like your dealer, Costco, others) may not do it, but others will. In my case, I ordered my wider tires online from TireRack.com because TireRack had the lowest prices. I had TireRack drop-ship the tires to an approved tire installer of my choice, and the tire installer then installed them.

Good luck on whatever you choose to do. Between the 185/65/15 and the 195/60/15 sizes, I don't think there's necessarily a wrong and a right choice.

 

New tires again today on my 2005. For those who haven't read the entire thread, here's the history:

- Stock Tires replaced at 18,500 Miles with Goodyear TT's
- Goodyear TT's 195/60/R15 replaced about 45,000 due to excessive treadwear
- My goodyear dealer special ordered Kumho Solus KR21's 195/60/R15 to replace the TT's (only paid about 1/3 cost because or the short TT life).
- Today 97,000 replaced the KR21's with Michelin WeatherWise II's 195/65/R15. I found that the 195/65's were considerably cheaper. Not sure why there is a cost difference but perhaps I'll be accurate on my spedo now since it's a larger tire.

Initial observations: Much softer ride on the new Michelin tires even when inflated to 40/38 psi.
My biggest complaint about the Kumho KR21's was that they didn't seem to grip the road as much as the TireRack reviewes indicated. They were however CHEAP so for the price, I don't think you can go wrong.

I hope to get much longer life out of the Michelin's so I paid the extra cash and here's to hoping!!:cheer2:

 

Thanks Brian for your reviews. Good luck on the Michelin WeatherWise II's. Hope you let everybody know how they work out for you.

Regarding the larger 195/65/15 tire, nyprius in his initial post observed that you might expect a 2.2% under-reading on the speedometer compared to the speedometer's reading with the OEM Integrities. But I don't remember the source (or its assumptions, if any) of his RPM numbers:

"In the 195, I looked at the 195/60R15 and the 195/65R15. The 195/60 has 863 RPM (.9% higher than the US OEM). The 195/65 has 836 RPM (2.2% lower than US OEM). According to others on PC, the Prius speedometer over-reads by 1-2 mph (ie: it says you’re doing 60 when you’re really doing 58 or 59 mph). The 195/60 has less than half the distortion of the 195/65. It would increase the over-read by less than 1%, whereas the 195/65 would reduce over-read by more than 2%, possibly resulting in under-read (a more risky condition). Personally, I don’t mind a little over-read. It helps to minimize speeding tickets. The radius of the 195/60 is .325 cm less than the 185/65 (about one eighth of an inch). So ground clearance won’t be affected significantly. (The 195/60 tire is .65 cm shorter than the 185/65, but the car would only be .325 cm lower.)"

 

Thanks Boo. You're correct that the decreased RPM will decrease the over-read and possibly lead to under-read. I plan to do a bit of testing with the Prius' GPS as well as my wife's portable GPS. I'll reply with what I find regarding actual speed compared to the speedometer speed. Like I said initially, the biggest benefit of getting the 195/65 was the price difference. If there's a bit of under-read, I'll just have to keep that in mind.

 

Those are all good reasons. Another is that not all tires come in all sizes. I chose the Goodyear Triple Treds, which aren't available in 185/65/15, but are made in 195/60/15.

 

I have about 48,000 on my Goodyear Triple Threads. I'm good at keeping the pressure at 40-38 and rotating the tires. Alignment was checked a while back and was fine. The tires are almost worn to their wear strips so it's time to replace. The TTs were great tires but I'm not happy about the wear or the road noise.

Has anyone gone from the TTs to the Comfort Tread? Any suggestions for another tire to try? I live in Florida so don't need the grip but we sure do get rain in the summer and the TTs were great in it.

Thanks.