Touring Edition Tire Upgrade

Let us know how much difference in mpg there is. What are you inflating them up to for pressure? Glad you posted. Other touring owners will be interested too! Thanks.

 

<div class='quotetop'>QUOTE(Bill_Lovett @ Sep 17 2007, 06:48 PM) [snapback]513983[/snapback]</div>

Did you notice a hit in mileage?

 

Bill,

I just got (yesterday) a new 08 Prius Touring and it came with Bridgestones. I guess I have not had enough time to notice anything wrong with them. What you didn't you like about these tires? I wonder if I could trade the Bridgestones for the Pirellis, or will I have to wait intill they wear a little (a year or so).

 

I will have to look at the Pirelli tires. For Colorado here, I've been considering the Nokian WRG2 (mean all season) or Hakkapelitta (winter monster) tire. Haven't seen too many reviews or experiences with them, so I will have to do it from first hand experience and hope for the best.

 

<div class='quotetop'>QUOTE(Bill_Lovett @ Sep 14 2007, 05:20 PM) [snapback]512745[/snapback]</div>

I also have been wanting to find a tire to replace the OEM's that came with my 2007 Prius. Does the the 205/55R16 change the width and hieght or just one. I don't really know that the 205 does the the size of the tire. Has it changed MPH or MPG from what you had been getting before?

Thanks for any input and sorry for any dumb questions.

 

<div class='quotetop'>QUOTE(topkick @ Oct 20 2007, 09:59 PM) [snapback]528345[/snapback]</div>

The 205/55R16 should only be a small, but sexy, increase to the tire width. I recently put 4 Nokian WRG2s on the car and it feels like a completely different vehicle. I let someone drive it after the new tires, who had only driven it once two weeks ago, and they were floored. They said it feels like a "real car" now only better. HA!

Good tires are the key to happiness.

 

I would still like to know what pressure you're running them at and what the difference in mpg is if someone can post that information.

 

<div class='quotetop'>QUOTE(Dahgu @ Oct 21 2007, 01:37 AM) [snapback]528381[/snapback]</div>

Thanks dahgu for the info. That helps me understand the numbers a little better.

 

Does anyone know if the RPM of the 205/55/16 size is different than the RPM of the OEM 195/55/16 size? (I guess the question is whether the tread width number is relative or absolute). EDIT: The middle number is a ratio, so if the ratio remains the same but the tread width changes, then the RPMs should change too, right?

I'm wondering if the RPMs are different --- what the effect is on speedometer, odometer and mpg readings.

Sorry for the question. I just never "got it" when reading the posts on this tire sizing/RPM issue in the other tire threads.

EDIT: I think I answered my question via google. See subsequent post below.

 

<div class='quotetop'>QUOTE(Bill_Lovett @ Oct 21 2007, 08:58 PM) [snapback]528597[/snapback]</div>

Hi Bill,

No problem. Thanks for the response.

I'm not sure I understand it all, but I think the height of the tire IS affected, albeit very slightly (imperceptible to the eye). I got curious about this question a few minutes ago while watching the 7th game of the Red Sox / Indians series, so I googled it. I found a tire RPM (revolutions per mile) calculator online and here are the short results:

The OEM 195/55/16 tire has 825.04 RPMs. The 205/55/16 tire has 810.68 RPMs.

This means that the 205/55/16 has a greater circumference of 1.77%. Not much.

So, assuming the Prius Touring odometer is accurately calibrated to the OEM 195/55/16 tire size, this should mean that with the 205/55/16 tires on your car:

[EDIT 10/23/07: Based on prim2's comment below, I realized that I was misreading the terminology in the online tire size/rpm calculator that I had used. So the following statements are wrong, i.e., the sequence of the two figures given in each statement should be REVERSED.]

* If your speedometer shows you going 60 mph, then you are actually going 58.96 mph. [EDIT: should read speedometer 58.96 mph, then actual 60 mph]

* If your odometer shows you went 100 miles, then you actually went 98.23 miles. [EDIT: should read odometer 98.23 miles, then actual 100 miles]

* If your MFD shows you averaged 50.0 mpg, then you actually averaged 49.1 mpg. [EDIT: should read MFD 49.1 mpg, then actual 50 mpg]

Anyone should feel free to tell me if any of my calculations or my express or implied assumptions are wrong.

One way that you could test all this in real life is if there's a route that you always take (e.g., to work), then just jot down the measured miles of the route with your OEM 195s on the car, and compare that to the measured miles of the route with the replacement 205s on the car. This comparison should show the 1.77% difference (assuming all other things being equal, like tire inflation psi).

 

<div class='quotetop'>QUOTE(Bill_Lovett @ Sep 14 2007, 05:20 PM) [snapback]512745[/snapback]</div>

Hey Bill,

I have another question for you (or anyone that knows). Does the Pirelli P4 tire come from an outlet like Sam's club or one of the others? I see where they can be bought online at several places but then have to get them shipped and locally mounted. Thanks for any info.

 

All looks great. Very handy link, by the way!

Cheers,

Geoff

 

Guys:

Discount Tires is having $100 off for a set of 4 tires. Very good deal!
I just got a set of 4 Sumitomo 205/60R15 to replace my poor Goodyear Integrity 185/65R15
(worn out at 22K - I don't inflat them to 40psi) for ONLY $192 ($0 shipping, $0 salse tax). (both are at 24.5" diameter)
You can easily find a local shop to mount them for $15/per + $4 stem/disposal
See here.
http://www.discounttire.com/dtcs/findTireSection.do
I was told that you could have the same deal at your local America's Tire. Not sure about this personally.

Tirerack.com is a very good resource for researching tires. They normally have better price than Discount Tires.
However, with $100 off, Discount Tires has better deal NOW.

 

Boy. I must still be in SRT8 mode. I spent $700 on a set of tires for my new Prius and thought it was a steal.