Performance tires and used Touring wheels on my Prius

Well, after a long and significant moral and philosophical debate with myself...and a bit of intervention from the Fickle Finger of Fate...I took Buzz to my friendly Toyota dealer for a tire and wheel swicheroo.

It's kind of funny how it all came to pass, if you've a moment.

It all began in my Mother's womb...
[laughing]

Okay, fast forward about forty-ahem years. After growing dissatisfaction with the original Integrities ---capped by a flat in Napa--- I decided to begin in earnest the quest for bigger and better shoes for my trusty traveling companion.

Originally, I bought a slightly used set of these: "The Potenza RE960AS Pole Position with UNI-T AQ II Technology" in 195/65-15's. They're 21 lbs. heavy, maximum pressure of 44psi, and sounded like they'd be reasonably sticky in the wet or dry...so I had them installed. Here's a pic:

[attachmentid=12218]

Over about 500 miles of mixed/spirited driving, I seemed to lose about 1-3 MPG, which is not too bad (1) to kind of a lot (3), in my opinion. And, yes, they were stickier, but they were kind of balloon-y and puffy looking to my eye and frankly handled like that too. Sidewalls too soft for my taste.

In the meantime, and on and off for the last nine months or so, I've been passively looking for a set of used Touring wheels. I thought I had a set for $450 on ePay, but the auction was canceled for "fraudulent use of one or more active accounts" and "in an order to maintain the integrity [sic] of ePay..."

I don't use eBay much for expensive things, and it was a bit ominous.

Anyway, in frustration, I went down to that Toyota dealer and checked in with their parts department again. Every so often, I'd swing by and see if somehow a set had shown up...

...and, indeed, one had! They're either off a new Touring Prius which had aftermarket wheels added, or from an unfortunate brand new Prius which was hit just as it left this dealership (I heard rumors of this thirdhand). The grey paint on two of them is a bit scratched but just on the surface, and there is one teeny-tiny ding on the edge of one, but they balanced fine and so I bought them for $450. They also sold me four new plastic covers, for which I paid "wholesale" ($60-something per cover).

This price also included four pressure sensors, which I think is pretty cool.

I'd decided that I didn't want to go with aftermarket wheels, although I briefly considered the TOM'S ones. But, what happens if I damage one of those a few years from now? Where would I ever get another?? And they're terribly expensive to begin with ($450-something each, plus tax and shipping) even if they're 12.-something lbs. each.

And, since the tires I wanted to go with aren't available in a 55 or 65 aspect ratio for 15" rims, the Touring rims actually seemed like not such a bad deal (sort of, but of course all of this is a waste of money, really).

Here's what I had installed, in size 205/55-16:

[attachmentid=12220]

26 [gulp] pounds of road huggin,' switchback carvin,' boulevard profilin,'...

..."The Potenza RE-01R (with the "R" signifying Revolutionary) is the Extreme Performance Summer tire member of Bridgestone's global family of Potenza performance tires developed for enthusiastic sports car, sports coupe and performance sedan drivers."

I know, I know, that's a TON of weight over the Integrities. And this isn't my old Porsche. But...but...at least they air up to 51psi maximum...that'll decrease rolling resistance a bit...won't it...? First impressions are that the car's initial acceleration (I think it's called "tip-in") is definitely more sluggish, but really does seem to carry momentum fairly well, still.

But, darn, it handles like a different car and seems almost immune to crosswinds.

There are, of course, the philosophical questions about such a thing; this will, potentially, make it even more complex:

[attachmentid=12221]

Yes, dear reader, it's the *TOM'S aftermarket exhaust,* complete with emissions-belching oversized CHROME exhaust tip!!!

I'm expecting delivery of my very own "fart can" [isn't that what the kids call them these days?]...I mean, it'll be replacing the stock muffler...you know, on the car, silly...
[laughing]

 

I don't honestly even know how heavy the Touring wheels are; I chose them to attempt to retain a stock look to my car (but the chrome tailpipe will mess that up a bit). Also for relative ease of replacement in the years to come. It's just me, but I've never bought a set of aftermarket wheels for a street-driven car.

As far as the weight of the tires, it's worse than you've calculated. I believe the stock Integrity tires weigh 14lbs/tire, and mine weigh 26lbs/tire. That's 12 pounds per tire...not to mention the additional weight of the wheels!!

I suspect that, actually, I'm driving around with the equivalent of EIGHT stock tires/wheels on the car!!!

Oh yes, I'm bracing myself for the worst, mileage-wise. The lighter wheels might be a good idea, but I couldn't begin to calculate a break-even point! And, speaking of rotational mass, it's really apparent how initial acceleration is a bit off, but it seems to carry momentum (but of course it must be a loss, overall).

After a weekend of "spirited" [ahem] driving, mileage on this tank is down to 39.2. That's a bit disturbing, actually. But, darn, the car feels pretty good.

A few observations:

(1) The unsprung weight really is noticeable, at least to me. Ride quality is definitely worse (but I've got 50psi in the fronts and 45 in the rears, so that's not helping) and she kind of skitters a bit over repetitive small imperfections in the road.

I'm feeling like the damping is no longer in sync with the spring rates. That's actually what's most disturbing; before, the TRD suspension bits were pretty nicely matched to the weight of the stock wheels/tires...now, it's all a bit off.

I'm already wondering about stiffer shocks and struts, but that won't be happening anytime soon (if ever). Overall it's still a big net gain, but while the limits seem much higher now, the balance of the car isn't as good. Initial reactions are that it's a bit...quirky. But, I'm a bit quirky, too...
[smile]

(2) The higher cornering forces really bring out the worst in the architecture; I don't have any of those TOM'S braces on her (only the BT plate) and I can sometimes feel things shifting just a bit...again, it's difficult to describe but I can tell that the chassis isn't providing as solid a mounting place for the suspension as it should...this could explain the inconsistent feeling, as things flex unexpectedly(??)

Haven't noticed anything moving in the cowl area, thank goodness; rear view mirror doesn't waggle, and the edges of the dash panel can't be seen shifting against the doors or A-pillars. One or two new little creaks, though, and the speedo display shakes a LOT over bumps now.

(3) These tires, themselves, are sweet!! Sidewalls are nice and stiff, and there's no tramlining when the road is scored. Road noise isn't too bad, either. Even with them aired up, the ride could be a *lot* worse than it is. A bit much for most Prius drivers, but so far so good (we'll see about treadwear).

Nothing is rubbing, either, but fender clearance is pretty tight. It's really a pleasure to have good tires on my car again; those Goodyears really were a disappointment to me (and I was not expecting very much).

Well, that's it so far.

There's one other thing that's interesting:
(4) The stance of the car is a *lot* more aggressive than before. And, I don't know if it's me or not, but (after only a weekend) I don't seem to be hassled on the road quite as much.

There were two instances where I thought to myself, "oh oh, they're going to pull out in front of me...the dreaded Prius factor..." but it didn't happen.

Again, we'll see how it goes, but the most important thing of all is that *I* like how it looks and feels...(selfish, no?)
[laughing]

--Natalie

 

<div class='quotetop'>QUOTE(apriusfan @ Oct 29 2007, 02:09 AM) [snapback]531858[/snapback]</div>

I think that's what I'd do, too, if I went aftermarket. No doubt about it, the Motegi's are the setup to go with; I've just got this hangup where I like the car to seem absolutely stock at first glance, sort of a sleeper. Wondering, now, how I might dull the sheen of the TOM'S exhaust.

<div class='quotetop'>QUOTE(apriusfan @ Oct 29 2007, 02:09 AM) [snapback]531858[/snapback]</div>

And how! The only thing I can do to mess up your numbers is to suggest that I might/might not get another set of tires like these. I wanted to see what the "max" felt like, so I could then dial back from that if need be. But, yes, the mileage is a concern to me.

What's weird is, that there's a current post about an '06 not getting as good mileage as an '07...

...mine's an '06 and, even when it was bone stock and I was hypermileaging all over the place, I never could even eek 50MPG out of it with consistency. 'Normal' driving for me yielded about 43-45MPG. So, oddly enough, I don't think it's fallen as much as some of the folks who routinely get 55+ or better. I've NEVER been able to get close to those numbers...but I am a constant here.

<div class='quotetop'>QUOTE(apriusfan @ Oct 29 2007, 02:09 AM) [snapback]531858[/snapback]</div>

I think the chassis flex is, indeed, a problem. It's just like, I go into a curve and the weight transfers...it's beginning to set up and I'm aiming for the apex...but something kind of shifts and those calculations don't always add up as I guess I've come to expect. It's worst if the road has an unexpected 'whoop-de-do' in it...I can just feel the structure flex, it's the oddest thing.

The whole top of the panel --especially that little top horizontal 'eyebrow' part above the smoked glass IP display, where it's most obvious-- will just go shaking up and down if there are little repetitive bumps in the road (say, a series of personhole covers or if there are tree roots below the asphalt), and the speedo display will move along with it. I first noticed this when I had the TRD parts added, but now it's *really* apparent.

In an odd way, though, I kind of like it.

<div class='quotetop'>QUOTE(apriusfan @ Oct 29 2007, 02:09 AM) [snapback]531858[/snapback]</div>

First off, I think it looks fabulous. I just like it, I can't explain...it's not so other people can see it, it just makes me feel better, I guess (weird).

The Integrities aired up to 44/42 were like slabs of foam compared to these. Those other Bridgestones (again, 44/42 and 65-aspect ratio) impacted ride quality a little, but I'd say only a third or half as much as what I've got now.

I think you're right, it's a combo of lots of unsprung weight plus really, really stiff-sidewalled tires aired up to the max plus the TRD suspension, combined with the lack of chassis bracing.

It sometimes actually feels like an old V8 musclecar with a solid rear axle...where it just kind of skitters over little bumps and the only opportunity I have to influence the direction of the car is, when the tires are actually touching the pavement.


But with this car, I think the tires aren't actually leaving the ground, it's just a feeling that happens to be very familiar to me. Skittering; I don't know how else to describe it.

[blushing]
I'm TOTALLY digging it, if everyone here hasn't noticed yet.

<div class='quotetop'>QUOTE(apriusfan @ Oct 29 2007, 02:09 AM) [snapback]531858[/snapback]</div>

Absolutely; thanks for your thoughtful reply.

--Natalie