I declare the Prius group buy of Nokian NHRi tires to have begun! This project was initiated by Betty Hamilton, and I have done some additional emailing with Ryan at Tirefactory. His most recent email to me (copied below) will answer most questions, but let me make some other comments first.
The Nokian NRHi tire is low rolling resistance, as was the "famous" Potenza OEM tire on US 2001-2003 Prius. It is manufactured in a relatively "environmentally friendly" way, which you may read about at the Nokian web site. It is a unidirectional tread design (as is the Michelin Hydroedge), which means that tires are mounted differently on the rims for the left and right side of the vehicle. The tire rotation pattern then becomes front to back, with no crossing pattern.
As Ryan mentions below, the OEM size of this tire, 175/65R14, has an 82 load index vs. 84 of the original. He regards this as adequate for Prius. But many will know that this has been much discussed in the past. At present I am using 81 load index tires on a 2001 Prius, and they have performed very well. But my next set will 84 or higher.
If I understand the other specifications correctly, all Nokian NRHi tires are 51 psi max, 320 tread life, "A" traction and "A" temperature.
I intend to order the 185/65R14 90H XL tires from Ryan. He wondered whether the extra half-inch diameter can be accommodated, and I am quite sure that it can. He has not yet quoted a price for this size, but I guess it will be about $95 each.
Today I emailed him whether we all need to order exactly the same thing, and don’t have an answer to that yet. But assuming that we can mix n match, you are all free to choose your own.
Tire Factory also sells Nokian WR, which is supposed to be an excellent winter tire. Perhaps someone will want those? If anyone with the new model Prius is in the market for tires, they may want to consider the Nokian NRHi 185/65R15 tire.
The process seems pretty straightforward. Everybody calls Ryan and tells him what they want. Presumably, the total number of customers will be 10 or more, and we will all get the discounted price and free shipping to 48 states, and no sales tax except for Michiganders. His end-date is 31 October, so get crackin’.
It should be obvious that there are some additional costs. Tire installation and spin-balancing typically runs $10 per tire. Most or all states levy a small tire disposal fee.
I am pretty excited about this, although I may store the tires for a while before installing them. Or maybe I won’t be able to wait! I am posting this message on the Yahoo toyota-prius and 2G groups, PriusChat, PriusOnline, and Green Hybrid. Have I missed any?
Thanks for the e-mail and the enthusiasm in starting a group buy! The 175/65R14 Nokian NRHi does in fact have a 82H Rating which is lower than the stock 84 load. However, the NRHi in that size would be a fine fitment as it still holds up to 1,047 lbs per tire at max inflation.
The 185/65R14 would be .5" taller than the stock size and may not clear your fenders properly. An alternate size in the 14" would be the 185/60R14, however that only has the 82H rating as well.
We would be willing to offer $10 off per tire saving $40 per set with FREE SHIPPING in the Continental US and NO sales tax outside MI. People can call us at 800-576-1009 to place the order and we accept all major credit cards. To give you a reference the price on the 175/65R14 with the discount would be $89.99 each and the 185/55R15 would be $94.99 each. We are willing to offer this pricing immediately through 10/31.
Tire Factory, Inc
Ryan’s email address is tirefactory AT tirefactory DOT com
Even w/o reponses to this, I post the following updates:
You can get the discount and free shipping with any Nokian tire in any size. If yu are looking for winter tires, or have the new model Prius with 15 inch wheels, you can play too.
The 10-buyers limitation has been lifted. You will get the discount regardless of how many people call 800-576-1009.
Ryan told me he has steel wheels for winter tires, but I don't know if his prices for these lead the market.
I posted Ryan's email wrong before. The correct is
tirefactory AT tirefactory DOT net
Did I mention that I will get squat for doing this? It's just that these seem to be pretty good tires, and I'd hate to see any of my Prius friends driving on worn-out tires. It's too bad, I could use a cut.
You can see that an 84 index tire has a 5.2% increase in load-bearing capacity. A quick search indicates the 1st gen Prius had a curb weight of 2765 pounds. The max GVWR should be in the doorjam, but it's probably a thousand pounds or so. That brings our max vehicle weight with passengers and luggage to 3800 pounds or so. In such a configuration, you've probably achieve near 50/50 weight distribution since the rear seat passengers and bags add a lot more weight to the rear than the front. 3800/4 = 950. That puts you at 91% of max load of the 82 rated tire and 86% of max load of the 84 rated tire.
Deciding on which tire you want to use would be a personal decision based on how comfortable you are running in the upper reaches of a tire's max ratings as well as how often you have a bunch of large people and heavy bags in your car for long highway trips.
Thanks for adding this info. Back in the old days of Prius (2001), there were many discussions about tire adequacy. I suppose they arose because there were quite a few problems with the OEM tires, especially those labeled "CHA" on the sidewalls. Later Bridgestone Potenzas were labeled "JDH", and were much less trouble.
It was a pretty universal observation that tires inflated per Toyota's spec (35 psi front 33 rear) would wear rapidly at the edges, characteristic of underinflation. As those tires also had a max. cold inflation of 50 psi, many got better results with inflations like 42/40. The worst problems might develop with lesser tires (like 81 load rating) inflated low like Toyota says, and with a heavy load.