Gord96BRG

I want narrower tires, but not shorter tires - no point in reducing the already marginal ground clearance and throwing off the speedometer! The equivalent diameter to OEM in a 17" size is 215/55-17. A 205/55-17 is too short, and the 50 and 45 series are even shorter.

There are quite a few other winter rated tires that aren't on your list, too.

Regards,
Gordon

canzoomer

Narrower tires would be 195 instead of 205
In picking 205, this is narrower than 225 (the stock width)
205 is the width of the tire, in mm
55 is the sidewall height, expressed as a percentage of the width.

See:
http://www.gmtips.com/3rd-degree/dox...ires/tires.htm

If we use a 17" wheel, we lower the car, but by selecting a 205/55/17 we end up with a tire diameter very close to the stock 225/45/R18

Like this:
18" wheel, converted to mm is 457.2
225 times 45% times two is 202.5
457.2 + 202.5 = 659.7

17" wheel, converted to mm is 431.8
205 times 55% times two is 225.5
431.8 + 225.5 = 657.3

The car would sit 2.4mm lower than with the 18" stock setup.

If you wanted more wheelwell tire clearnace select either a 205/45/17 tire: 616.3 ( 43mm lower than stock)
195/55/17 tire: 646.3 ( 13mm lower than stock)

Bear in mind that the more you deviate from the 659.7 figure the more your speedo is off, assuming it is right in stock trim.

That would throw your speedo off a bit though.
For examle, with the 195/55/17 setup:
pi x d is the formula, so:
Stock:
225/45.18: 3.1415 x 659.7 = 2072.4
205/45/17: 3.1415 x 616.3 = 1936.11
1936.11/2072.4 = 93.4% of the original, so at 100km/h original speedo reading you would actually be going 93.4km/h

Wing

canzoomer:
215/55/17 is closer than 205/55/17 93% is A LOT off!

If you use 215/55/17 the difference is 1% above, so when showing 100Km/h your going 101Km/h that's closer.


Anyone jack their car up yet?

I did this weekend, WHOLLY CRAP!

There is about 1 foot of spring stretch before your wheel comes off the ground!

I took off my tire and heck you could have a party in that wheel well!

canzoomer

Math time:
Stock tire: 225/45/18
.45 x 225 = 101.25
2 x 101.25 = 202.5
Stock wheel: 18"
18 x 25.4 = 457.2
457.2 + 202.5 = 659.7

215/55/17:
.55 x 215 = 118.25
2 x 118.25 = 236.5
17" wheel:
17 x 25.4 = 431.8
431.8 + 236.5 =668.3

668.3 / 659.7 = 1.013

Now let's do that with 205/55/17:
.55 x 205 = 112.75
2 x 112.75 = 225.5
17" wheel:
17 x 25.4 = 431.8
431.8 + 225.5 =657.3

657.3 / 659.7 = .996

Even closer to stock diameter ( less than half a percent), smaller contact patch, lower cost tires, more readily available size, more wheel well clearance by using a narrower tire.

I rest my case.

Gord96BRG

Who cares about wheelwell to tire clearance? (PS - save the math, I fully understand all the parameters in the size designations. If you really want to do math, look up the actual tread width and diameter numbers from the manufacturer's websites for comparisons instead of using the nominal values - there can be significant differences between tires of the same nominal size but from different manufacturers.) If you run a shorter diameter tire, you will lower the ground clearance of the car - the car will sit closer to the ground by the difference in radius. Why run a shorter tire in winter that will lower your car closer to the snow/slush? It's a great idea for Solo competition, but otherwise...

Regards,
Gordon

Wing

Canzoomer I was going by YOUR numbers on the tires. I just noticed you actually put in 205/45/17 that's why!

Sorry for the confusion.

Anyway, I have an appointement for saturday to try out some steelies.

If they don't fit they will be doing measurements for the perfect fit 17" alloy.

Well know all the important numbers than.

canzoomer

2 reasons:
More wheel well clearance, so that if snow packs in there is less chance of your wheels.
The RX-8 has lots of ground clearnace to start with, so a few mm is not going to matter much..

Gord96BRG

I guess you and I define "lots of ground clearance" differently!

From Mazda Canada web site, RX-8 (laden) ground clearance is 120 mm, or 4.7".

Other vehicles of note:
Infiniti G35C: 6.3"
Acura RSX-S: 5.9"
Celica GT-S: 5.5"
Subaru WRX STi: 5.7"

Regards,
Gordon

canzoomer

I have a big curb on my driveway.
I clear it (just).
I have a friend with a G35C and he does NOT clear it.

I just measured it on my driveway and I get 5.5" which is at the catalytic converter in the middle of the car.
The rest of the low points are all cross members, and they are about 6.25" from the ground.
There IS a rubber lip hanging down in front of the front wheels, and it measures about 5", but it is very flexiblem, and just bends back at a slight touch.

Ron_Jeremy

Hey Guys....
I've been outta touch lately (super busy with work and stuff) ...but definitely interested in winter tires as well ...look forward to hearing more about your findings/recommendations and a group buy....

mdmaclean

Gord,

If my post was the one you were referring to, the Blizzak LM-22 (a diferent tire than many Blizzak's), is the only winter tire that I am aware of which is available in a size which matches the stock tire size.

I don't think that the LM-22's are that great in snow, but apparently handle quite well. FYI, my current winter tires from the BMW were Pirelli P210 Snowsports.

Gord96BRG

Nope, not yours, it just seems that any time a winter tire discussion comes up people almost automatically start talking "Blizzak"! (here, and on the Miataforum, and elsewhere) You're right, the LM-22 is a better choice for an RX-8, but in a -1 size (17", slightly narrower) they don't have a proper size (215/55-17). I wouldn't put a WS-50 on any car I owned, so that leaves only a few alternatives.

How did you like the Pirelli 210s? I've a little bit of experience with them on a Miata, and they seemed to do OK.

Regards,
Gordon

canzoomer

Thanks Wing!

I look forward to hearing how it worked out.
Wether through group buy, or on my own I DO need to deal with this pretty soon, as here in Edmonton we could easily see snow quite soon..

BTW, regarding group buys, do any of the Alberta and B.C. owners want to get together and work on one with a couple of the vendors online?
I will gladly help organize this.

Ta!

Canada

Wing,
I just got my RX-8 today. It is a blast (automatic and all)! But now that I have it, I can go to the Talon Tire for you on Saturday, to try the varios rims, if you don't want to drive all the way here to Montreal. I am extremely busy during the week at work for the forseeable future, so I definitely have to make it a Saturday. Since you've already convinced them to be open for you this Saturday, I could sub for you if you want. Just let me know.

Wing

Check your private messages Canada!
Or your e-mail.

Canada

I'm there!

Wing

Did you call them to confirm? Yes you did


Ok guys, I talked to John at Talon Tire.

He had good news and bad news.

Good / Bad news:

Mac pac (HUGE wheel company in Montreal) sent him a 16" and 17" steel wheel, that they THINK will fit. He seemed a little skeptical because of the centre bore. He told me he will try them on Canada's car anyways, because MacPac wanted to know if they fit. He thought, sure they might fit, but he feels they would create vibrations and such because of them being the wrong centre bore.

He said, most shops will sell anything, but if the measurements are off he said he won't sell them as they would cause wear on the drivetrain, even if they fit over the breaks.


He also ordered in a 16" steel HE thinks will fit, and a 15", although we all doubt a 15" will fit.

Last resort:

If these wheels do not fit, we will have to go with an alloy. He will be taking ALL the required measurements from the stock alloy make sure we have a perfect fit in 17" alloy.

Canada, keep us posted! If Canada disappears (driving into the sunset) I'll call them again Tuesday.

Have a fun long weekend guys! Drive safe!

Quick_lude

Hey guys, fwiw from a large amount of feedback we get in our club the Toyo G02's are probably top 3 winter performance tires. Talon Tire is an affiliate of our club and John is a great guy to deal with and always available to help out.
Not sure if the Nokian Hakkapellita are available in your size but those tires are also top 3 imho.
http://www.nokiantires.com/newsite/homeF.cfm

Wing

Yeah John is awesome, he recommended the Toyo's as well and said they were fairly inexpensive, actually on the cheaper end of the scale!

He also (as well as another shop) recommended the Yokohama AVS901's and the Dunlop M2's or M3's

Gord96BRG

Please make SURE he tries a few different 16" alloys as well - they're more likely to fit than 16" steelies, and give us more and cheaper winter tire options than 17"...

Regards,
Gordon

canzoomer

Here is what I am going for:
I Think these are the best bet for me at least here in Edmonton, where we get a lot of ice, not much really deep snow..

Nokian WR in 225/45/17 H rated for speed.
KAL Tire is selling them for $254 each.
Anybody know o fother sources?

References:
http://www.canadiandriver.com/articles/hl/nokian.htm

http://www.nokiantyres.com/nokian_wr_en.html

Their dealer locater is at:
http://www.nokiantires.com/html/map.htm

Ta!

canzoomer

As I mentioned in my previous post, I have decided that i think the best best are the Nokian WR tires.

I dropped by the local Nokian dealer today (KAL Tire) and they trial fitted some 17" alloy winter wheels they are selling.
They are 17" x 7" with 38mm offset, and are fairly clean, so should not hold a lot of dirt.

For those worried about clearance inside and out, no problem. I can put my fist between the wheel and the struts, and between it and the fender.

KAL Tire have offered a group buy discount, so, if the moderator does not mind, i would like to post the offer..

mdmaclean

The P210's were fine in the snow, and I never got stuck anytime. What I did not like was the BIG change in handling between the 235/45R17 Pirelli P6000's in the summer and the P210's (225/55R16) in the winter. On dry winter/spring roads, the grip was not there. All in all, I am hoping to do something sharper handling, but I could end up with them again.

Now that I am buying winter tires for the RX-8, I am debating maximum snow traction compared to better handling. I also expect that the LM-22 route will be a lot more expensive, both up front and for replacement tires later.

Wing

canzoomer, the offset on the stock wheels is 50mm, 38mm will create load on your bearings!

I wouldn't put anything lower than 42mm or even 45mm on.

What was the "standard" price of the rims, and the tire seperatly?

canzoomer

With a 38mm instead of 50mm, the wheel hub inside is 12mm closer to the centre of the car.
That would create LESS load on the bearings, as it sticks out less distance..

With the stock width wheel this would bring it closer to the inside of the wheel well, but as these are narrower wheels it works out to put the centre of the tire in the same place, so the combintion of the offset and wheel width work out to the same wheel centreline within a couple of mm..

They quoted the wheels to me at $156, the tires at $254.33

If we do a group buy the tires drop to $220 and the wheels to $130

Install/balance is $12 per wheel, and stems are $2.95 per wheel.
Torque wrench install, no air.
KAL tires have branches all over the west, and as far east as Thunder Bay.
I hve to tell my salesman the names and cities to register people on the group buy, and he simply enters the info on his computer so that others can find the quote reference.

Total installed group buy price is $1,459.80
Add local taxes to suit.

I will take a few pics of the wheels today and post later.
They weigh 20 lbs. per wheel.