Tire Wear Info and Winter Tire questions

Repost, as my old thread went away...

I finally managed to find a tire tread depth gage, and I checked my tires. I took my best estimate/closest whole number when measuring.

I have about 23,000 miles on my 2001 Toyota Prius' OEM tires, I think that's about 2 years of service (I'd have to double-check my notebook in my car for the exact date). My usual pressure is about 41F/39R.

OEM Bridgestone Potenza RE92 XL
P175/65 R14 84S
original tread depth is supposedly 10/32"
Measuring the 4 main grooves, in x/32":
left outside ---> inside; right inside ---> outside
left front: 7, 8, 8, 7 ; right front: 5, 7, 6, 5
eft rear: 6, 7, 7, 7 ; right rear: 6, 6, 5, 4

My husband has about 24,000 miles on his 2004 Toyota Prius with OEM tires.
That's just shy of 2 years. Usual pressure is around 40F/38R.

OEM Goodyear Integrity
P185/65 R15 86S
original tread depth is supposedly 10/32"
Measuring the 3 main grooves, in x/32":
left outside ---> inside; right inside ---> outside
left front: 6, 8, 7 ; right front: 6, 7, 5
left rear: 5, 7, 6 ; right rear: 5, 6, 5

Unfortunately, neither car has been in for an alignment yet. But the tires do get rotated (or so says my paid work orders) at every oil change (6 months or 7500/5000 miles).

So, I have more tread wear on the edges, and it looks like about 2/32" of
tread wear per year...

Door jamb info for the US Prius, any model year, is 35psi front, 33 psi rear.

Most Prius owners tend to report edge wear on their tires. It's especially bad on the 2001-2003 Prius with the Bridgestone Potenza RE92 XL tires. So, to combat this, and to increase MPG, many owners either religiously keep their pressures at the factory 35F/33R, or go up to anything that's within the max. cold pressure as on the sidewall. The tire recommendations from the Classic owners just got translated over to the 2004-? Prius when it came out...

Max cold pressure for the US OEM Bridgestone Potenza RE92 XL tires on the 2001-2003 Prius is 50psi. Max cold pressure for the US OEM Goodyear Integrity tires on the 2004-? Prius is 44psi.

Just some data points for those out there...

Anyhow, the question I have is: is it time to dump these tires, or should I hold onto them for another season? (I know a number of Prius owners hate the OEM tires...)

I know that I need to invest in some snow tires for this upcoming MA winter. Last winter I kept sliding backwards down my paved but icy driveway with my 2001, and my husband slid into a snowbank or two with his 2004 BC (and the front bumper still keeps popping off of some of its clips).

I was thinking of just going straight to some Nokian WR A.W.P.2 tires (4-season tires with the Severe Service emblem) for full-time use, but...

Should I/can I just put the Nokian WR onto the current aluminum rims for this winter, change back to the OEM tires for the upcoming spring/summer/fall 2006, and then remount the WRs for the following winter and keep them on (dump the OEMs next winter)? Or should I get some steel rims just for this winter for the WRs, and then move them back to the alloys when I dump the OEMs?

Or should I just buy some steel rims and winter tires (Bridgestone Blizzak WS50 or Nokian RSI), and then have to look into buying another 3-season tire (Nokian NRHi or i3, LRR tires) in another year or so? (This seems much more expensive and more hassle than just going for the WRs above, but...)

Just looking for any tire/wheel advice. Thanks in advance!

 

You misunderstood me. Yes, I plan to change to some form of winter tire for the winter. The question is in what manner?

(When the OEM tires were new, I did not have sliding problems...)

The tires I'm looking at:
Nokian WR A.W.P.2 (4-season friction winter/all-weather tire with severe service emblem, and made in a more environmentally friendly manner)
http://www.nokiantyres.com/passengercars_p...&name=NOKIAN+WR
http://www.nokiantires.com/newsite/tires_popup.cfm?id=6

or alternately:
Nokian NRHi (3-season summer tires, LRR and made in a more environmentally friendly manner)
http://www.nokiantyres.com/passengercars_p...ame=NOKIAN+NRHi
http://www.nokiantires.com/newsite/tires_popup.cfm?id=54
with:
Nokian Hakkapelitta RSI (friction winter tires, and made in a more environmentally friendly manner)
http://www.nokiantires.com/newsite/tires_popup.cfm?id=53&w=1
http://www.nokiantyres.com/passengercars_p...KKAPELIITTA+RSi

My options look to be:
1. Take off OEMs and dispose of them. Put Nokian WRs on the alloy wheels until they wear out.
2. Take off the OEMs and hold onto them. Put Nokain WRs on the alloy wheels for the winter. Put the OEMs back onto the alloy wheels for spring/summer/fall (2006). Put the Nokian WRs back on the alloy wheels next winter (2006), and most likely dispose of the OEMs next winter. Keep the Nokian WRs on the alloys from then on.
3. Find some steel wheels, and mount the Nokian WRs on the steel wheels for the winter. store the alloys with the OEMs for next spring/summer/fall (2006). Maybe I'll get spring/summer/fall 2007 out of the OEMS, I don't know, but when they're ready to go just keep driving on the steel wheels with the Nokian WRs until they wear out.
3B. same as above but I move the Nokian WRs off of the steel wheels and back onto the alloy wheels, and sell the steel wheels.
4. Find some steel wheels, and mount the Nokian RSIs on the steel wheels for the winter. store the alloys with the OEMs for next spring/summer/fall (2006). Maybe I'll get spring/summer/fall 2007 out of the OEMS, I don't know, but when they're ready to go replace with the Nokian NRHi or whatever replaces it at that time.
5. Find some steel wheels, and mount the Nokian WRs on the steel wheels for the winter. store the alloys with the OEMs for next spring/summer/fall (2006). Maybe I'll get spring/summer/fall 2007 out of the OEMS, I don't know, but when they're ready to go replace with the Nokian NRHi or whatever replaces it at that time.

The most expensive initial outlay (remember that I'm dealing with 2 Prius here) would seem to be options 3-5 above. Option #1 is fairly simple and obviously involves the least amount of work... I'm leaning towards option 2 above, but I'm not ruling anything out just yet. (Well, I'm not moving to southern CA, as was one suggestion I've had...) Tire swaps would require a trip to a professional (we don't have the tools or ambition to change them out ourselves).

I do intend to do a full 4-wheel alignment before putting any new tires on. I suspect that I'll still see the edge wear, though. (It is far too easy to take a turn too fast in a Prius, and when riding with my husband in his 2004 he seems to suffer the same affliction, if not worse...)

I'm still trying to get my hands on a copy of the current (November 2005) issue of Consumer Reports which rates both summer and winter tires and their care. My local libraries have not received their copy in the mail yet, and I've asked family and coworkers and no one subscribes...

 

Last weekend I put on my new winter tire/wheel combo (generic black steel rims with Nokian WR A.W.P. tires). With the added weight of the wheel/rim combo, both Prius are a little more "growly" and have a feeling of driving in mud (slower to accelerate, but they do coast a bit better). I haven't encountered any wet/bad weather yet to try them out.

I'll go back to the OEMs for spring/summer/fall of 2006, and re-evaluate them come winter of 2006 to decide if I'll keep them (have enough tread left), dump the OEM tires and transfer the WRs to the alloy wheels for full-time use, or dump the OEM tires and get some new summer tires (or even use the WRs for summer use and get more agressive winter tires to put on the steel rims).

This week I took both of my Prius in for a 4-wheel alignment, as neither of them have had one yet (4.5 years/40+K miles on my 2001, 2 years/25K miles on the 2004).

My 2001 went to a new-to-me dealer. Alignment cost $79.95 (but the 60,000/48 month service mile service I did at the same time (I'm late for that by time, but not by mileage) was the least expensive in the area.) I got a nice color printout of the before/after and the specs for my car. Both the Left and Right Front Toe was out of specifications, and were adjusted. I do not know why the SAI and Included Angle were not measured. Now my 2001 does handle much easier/lighter (point and it's easy holding onto turns, but on the highway it is a light touch and can "wander" as I'm used to a tight track/holding).

My 2004 went to my usual dealer. Alignment cost $64.95. I had to ask for a copy of the printout, so they photocopied it from their records (so no pretty colors for me). Vehicle was in specifications, so they didn't adjust anything. (So, $64.95 to just get a photocopied printout.)


2001-2003 Prius, all figures in degrees
* = This value is not whithin specification. Tire wear, handling and safety problems may result.

Front (Left)
Camber: Specs: -1.2 to 0.3, Actual: -0.6, Before: -0.7
Caster: Specs: 0.3 to 1.8, Actual: 1.4, Before: 1.4
Toe: Specs: -0.5 to 0.15, Actual: 0.06, Before: -0.21 *
SAI: Specs: 9.1 to 10.6
Included Angle: Specs: 7.9 to 10.9
Turning Angle Diff.: Specs: ....

Front (Right)
Camber: Specs: -1.2 to 0.3, Actual: -0.6, Before: -0.6
Caster: Specs: 0.3 to 1.8, Actual: 1.0, Before: 1.0
Toe: Specs: -0.5 to 0.15, Actual: 0.08, Before: 0.28 *
SAI: Specs: 9.1 to 10.6
Included Angle: Specs: 7.9 to 10.9
Turning Angle Diff.: Specs: ....

Front
Cross Camber: Specs: -0.8 to 0.8, Actual: 0.0, Before: -0.1
Cross Caster: Specs: -0.8 to 0.8, Actual: 0.4, Before: 0.4
Cross SAI: Specs: -0.8 to 0.8
Total Toe: -0.10 to 0.30, Actual: 0.14, Before: 0.07
Cross Turn Diff.: Specs: ....

Rear (Left)
Camber: Specs: -2.3 to -0.8, Actual: -1.4, Before: -1.5
Toe: Specs: -0.12 to 0.22, Actual: 0.00, Before: 0.00

Rear (Right)
Camber: Specs: -2.3 to -0.8, Actual: -1.2, Before: -1.2
Toe: Specs: -0.12 to 0.22, Actual: 0.21, Before: 0.20

Rear
Cross Camber: Specs: -0.8 to 0.8, Actual: -0.2, Before: -0.2
Total Toe: Specs: -0.23 to 0.43, Actual: 0.21, Before: 0.20
Thrust Angle: Specs: .... , Actual: 0.10, Before: 0.10



2004-2005 Prius, all figures in degrees

Front (Left)
Camber: Specs: -1.3 to 0.2, Actual: -0.6, Before: -0.6
Caster: Specs: 2.4 to 3.9, Actual: 3.4, Before: 3.4
Toe: Specs: -0.10 to 0.10, Actual: -0.06, Before: -0.06 [edit: fixed typo]
SAI: Specs: 11.8 to 13.3, Actual: 13.0, Before: 13.0
Included Angle: Specs: 10.5 to 13.5, Actual: 12.4, Before: 12.4
Turning Angle Diff.: Specs: ....

Front (Right)
Camber: Specs: -1.3 to 0.2, Actual: -1.1, Before: -1.1
Caster: Specs: 2.4 to 3.9, Actual: 3.1, Before: 3.1
Toe: Specs: -0.10 to 0.10, Actual: -0.06, Before: -0.06 [edit: fixed typo]
SAI: Specs: 10.8 to 13.3, Actual: 12.8, Before: 12.8
Included Angle: Specs: 10.5 to 13.5, Actual: 11.8, Before: 11.8
Turning Angle Diff.: Specs: ....

Front
Cross Camber: Specs: -0.8 to 0.8, Actual: 0.5, Before: 0.5
Cross Caster: Specs: -0.8 to 0.8, Actual: 0.4, Before: 0.4
Cross SAI: Specs: -0.8 to 0.8, Actual: 0.2, Before: 0.2
Total Toe: -0.20 to 0.20, Actual: -0.12, Before: -0.12
Cross Turn Diff.: Specs: ....

Rear (Left)
Camber: Specs: -2.0 to -1.0, Actual: -1.3, Before: -1.3
Toe: Specs: 0.03 to 0.28, Actual: 0.19, Before: 0.19

Rear (Right)
Camber: Specs: -2.0 to -1.0, Actual: -1.6, Before: -1.6
Toe: Specs: 0.03 to 0.28, Actual: 0.17, Before: 0.17

Rear
Cross Camber: Specs: -0.5 to 0.5, Actual: 0.3, Before: 0.3
Total Toe: Specs: 0.05 to 0.55, Actual: 0.37, Before: 0.36
Thrust Angle: Specs: .... , Actual: 0.01, Before: 0.01