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Discussion Starter #1
Re: Potenza RE92 was Re: Bridgestone Ecopia EP-03 Tires

Ricky Suiter wrote:
> The Potenza RE92's in the 165/65R14 and 175/65R14
> sizes are LRR, but there are no numbers in the green
> seal report. The 165 is the OEM Honda Insight tire,
> the 175 is the OEM Prius tire. The 175 size also comes
> in an XL or extra load rated tire so that might be the
> thing to get for your conversion.

The tires that come on a new car are *not* the same tires you and I get
in a tire store. Auto companies buy tires by the millions, so they ask
for (and get) special tires made to order. If they want a lower price,
or lower rolling resistance, or higher load capacity or whatever, they
get it!

But when we go into a tire store, we get the generic equivalent of that
tire. It may have the same name and be the same size, but it's a
different version. It won't have whatever special characteristics the
auto company demanded.

For example, Toyota wanted a low rolling resistance tire with a higher
load capacity for the Prius. So, they got a special Bridgestone Potenza
RE92, with extra load capacity and low rolling resistance. Replacements
from a tire store will have *normal* rolling resistance and load
capacity. They will try to sell you what they *do* have in stock; some
other tire, even another Bridgestone Potenza that they say is "just as
good". It may be cheaper, and wear longer, and handle better (the things
consumers ask for at tire stores); but it won't be low rolling
resistance or extra load capacity. To get that, they'll have to special
order an OEM replacement tire for you.

Also note that everything has tradeoffs. When you increase one
parameter, other parameters get worse. The special low rolling
resistance version Prius tire had half the life of regular version.

> Not having any numbers I will say this about them
> though. I was very active on the Insight Central
> forums when I had my Insight and lots of people asked
> about tires and those who didn't listen and put
> regular tires on their cars always lost 5-10mpg
> depending on what they put on the car.

Yes; same with the Prius. Tire store tires (even the same make and
model!) had worse mpg. The 2004-2007 Prius comes with Goodyear Integrity
185/65R15 tires "made in Japan". A tire store Goodyear Integrity
185/65R15 is "made in USA" and is not the same tire. It may have
improved life, quieter, handles better, etc. -- but it doesn't have the
same low rolling resistance.

> Now I should mention I'm not sure what the case is
> with any of the Potenza's that are larger, they may
> not be LRR, but here's a way you can probably check.
> The 165 and 175 size are made in Japan, they say so on
> the sidewall. If the larger sizes are made in the US I
> would bet they aren't LRR.

Right!

--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
 

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Discussion Starter #2
Re: Potenza RE92 was Re: Bridgestone Ecopia EP-03 Tires

Lee Hart wrote:
>
> The tires that come on a new car are *not* the same tires you and I
> get in a tire store.

That's a pretty definitive statement there Lee! ;-)

I'd venture to say that tires that come on a new care *may* not be the
same tires you and I get in a tire store, but I'd be surprised if they
were *always* different.

FWIW, I saw no appreciable change in mileage, noise, or feel when I
replaced the OEM Potenza RE92s on my Insight with a replacement set of
the "same" tire. Granted, I did not do a complete comparison of
sidewall data between the old and new tires.

cheers,

Andrew
 
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