maddog2112

Hello all, new to the rx8. Ive got an 06 with the stock 18 inch wheels. This will be my first winter in Louisville Ky. We don`t get much snow but I dont want to risk it so I`m planning on getting some snow tires, either the Blizzaks or Dunlop M3s. Are you guys putting the snows on all 4 wheels or just the back? Also, can you put a 16 or 17 inch tire on the stock 18 rims? I was just planning on swapping snow tires onto stock rims for winter and back to originals for the rest of the year. What are you guys doing? I also hear a couple of sand bags in the trunk are very helpful??

paimon.soror

iTrader: (15)

1. I love my blizzak ws70s ... going on my 4th season. No issues whatsoever. No sandbags needed

2. No you cannot put a 17" tire on a 18" rim

3. Recommended to put wheels on all 4 corners.

dynamho

I've tried both Michelin X-Ice xi2 winters and Continental ExtremeContact DWS all-seaons (not DW).
Unless you have hills and don't want to swap tires, the Conti's are also fine for snow. They are also a lot of fun for autocrossing because they slide well, but forget it if you're competitive.

The Michelins are awesome on both snow and ice.

RIWWP

iTrader: (2)

The myth that sandbags in the trunk helps is from people that take a very narrow set of circumstances and apply it across a wide range of uses without thinking it through. On some napkin math, two 40lb sand bags will increase your rear tire traction by about as much as opting for 215mm width tires instead of 225 width tires. It's all about pounds per square inch, and getting a narrower tire is more effective because you are increasing the pressure on the contact patch without adding more weight to the car that you then have to try to keep under control.

Pickup trucks with big engines up front and zero weight in the rear, but still rear wheel drive, benefit from weight in the back more because it is shifting the truck to have a better weight distribution. The 8 already has far more weight over the rear axle than most pick up trucks (thanks to weight distribution).

the "18" par of the 18" wheels means that your wheels have a diameter of 18 inches. You can't fit a tire that is a different inner diameter simply because the circles are of different sizes. The numbers that you can change are the tire width and tire sidewall (which is expressed as a percentage of the width)

Highly highly recommend all 4 wheels. If you leave summer tires on the front, you will be able to accelerate still, but you will still have not much braking ability and no steering at all.



Stick 4 proper winter tires on an RX-8 and it is a fantastically stellar snow car.

dynamho

BTW, generally, you want to go thinner for winter. Since 225 is stock, so 215 is a recommended choice.

NotAPreppie

Expounding on what RIWWP typed regarding sandbags:

There are two major concepts that govern what happens in a car: friction and momentum (well, inertia really but lets not get pedantic). Friction is dictated by three things: mass, gravity and coefficient of friction. Mass is mass and gravity is gravity. Combine them and you get weight. So, friction is partially dependent on how much weight you have. The coefficient of friction is dictated by how well the tire resists slipping. When dealing with snowy roads, the coefficient of friction is far less than 1 (generally from 0.3 to 0.6, we'll come back to this later).

With me so far? Okay, lets move on to momentum. Momentum is a measurement of how much force it takes to speed up, slow down or change direction. It's a function of two things: mass and velocity. If you increase mass, you increase momentum and it becomes more difficult to speed up, slow down or change direction.

Now, if you increase weight (mass), you increase friction. Makes sense. However, you also increase momentum. And, because the coefficient of friction on snow is so low, your increase in momentum is going to be much greater than the increase in friction. This means that more mass will actually make it more difficult to start, stop and turn. Add 100lbs to the trunk and your momentum will go up as if you added 100lbs but your friction will only go up the same as adding 30-60 lbs.

(Incidentally, this is also why a 1 oz. marble and a 16lb bowling ball fall at the same rate. Sure, the bowling ball experiences a greater force of gravity but it's extra weight means it resists acceleration more so it all evens out.)

THIS IS WHY RACE CARS ARE BUILT TO BE AS LIGHT AS POSSIBLE! If adding weight to a sports car made it handle better, race cars would weigh as much as a Peterbuilt. Seriously, the best things you can do are reduce weight and improve the coefficient of friction. That means ditching the sandbags and getting a good set of snows.

As RIWWP typed, adding weight is really only useful when most of your weight is at one end but your drive wheels are at the other. Biasing weight back over the drive wheels will make your car easier to drive. However, the RX-8 has ~50/50 weight distribution so it's more than a little stupid to do it in this car.

RIWWP

iTrader: (2)

Incidentally, my 2300lb 1999 Miata was much better in snow than my 3,000lb RX-8, both with snow tires, both with near 50/50 weight distribution.

Far less weight to have to control, just as much traction (proportionally similar tire widths). The 8 was still stellar, but the Miata was just a noticeable bit better.

Carbon8

iTrader: (4)

Had the same experience with an 8 a couple years ago, went threw a buffalo winter and feet of snow and never got stuck. Tires and driver make all the difference.

maddog2112

Wow!! Very impressed with the knowledge and quick responses from you guys. Even though the 18in tires will be quite a bit more expensive than a 16 or 17, I think I will go with the blizzaks on all fours without buying a second set of rims. I don't think I would want a cheap set of rims on my car and hate to spend the money on a second nice set of rims.

RIWWP

iTrader: (2)

If you are worried about cheap quality, you can get OEM quality with cheap costs. Just look for OEM 17" stock wheels for the Mazda6, Mazda5, Mazda3, CX-5, CX-7, CX-9. Their 17" wheels are a perfect fit and you can usually find a set for relatively cheap.

NotAPreppie

Depending on mount/dismount/remount costs, buying a cheap set of wheels can pay for themselves in less than 4 years. Especially if you go with a 17" option since the tires will be a bit cheaper.

maddog2112

Just curious if any of you have used 16's for winter tires. I found a set of Mazda 6 protege wheels.

Loki

iTrader: (1)

16's won't fit over the front brakes, minimum you can do is 17". If you end up buying from not a store, make sure the overall tire diameter is close to the stock 18" tire diameter. Search google for tire size calculator, there are many.

Mazda 6 protege eh?

NotAPreppie

Tire size calculator This is my favorite though it doesn't take into account offset, backspacing or caliper clearance.

Some 17" options won't fit over the brakes but if you call up Tire Rack (FORUM SPONSOR!!!) or Discount Tire Direct, they should be able verify whether or not it will.

Honestly, if these are your winter beater rims, there's no reason to go ***** out with the quality. I mean, you're going to beat the crap out of them so no sense in going with any wheel that costs more than $100.

As far as tires go, I know you called out Blizzaks and Wintersports (both good tires) but I wanted to extoll the virtues of the Nokian WRG2 (or the newer WRG3). Louisville, KY doesn't get horrible winters (compared to where I live in Chicago which is nothing compared to farther north) so a pure snow tire may not be warranted (there's even one moderator on this forum that recommends a good all-season instead of snows). The WRG2 (and G3) can be thought of as a snow tire tread pattern with a more all-season compound. It grips pretty well in the snow (admittedly not quite as good as a true snow tire) but doesn't wear out nearly as fast so you can leave them on the car longer if you can't get around to having them switched out.

I had them on my '8 through several Chicago winters and was very happy with them.

Silverdollar

Thx for the info on snows. So I am going to try snows for first time ever on my 04 with 209k and I was planning on going with 18 inch 215. What are your top suggested snows. Also, RIWWP info on the viability of using 17 OEM wheels sounds like an awesome suggestion. Has anyone else taken that route?

Silverdollar

Forgot to mention that I love driving my RX8, and have always feared snowy days in it, as I just didn't think it could handle it well, after having a dicey situation with it the 2004 winter when I lived up in SE Pennsylvania. I've had my baby since birth in 04, and will give it a shot with snows, as I am greatly encouraged by the positives posts recommending putting on good snows and it handle well. I must say that my 88 RX7 which I drove up to 325k handled the snow fine, but this RX8 is balanced differently.

New Yorker

FYI, the industry term is now "winter tires" — not "snow tires".

What's the difference? Back in the day, people put on snow tires when it snowed or was icy. But one should replace summer tires with winter tires when it gets below a certain temperature (about 40ºF, I believe) even if the roads are dry. Our summer tires get very hard ("turn into hockey pucks") below 40º and lose much of their traction.

Gravey

iTrader: (3)

I went with 205/50's on 17's do you guys think that is too narrow?

paimon.soror

iTrader: (15)

sounds about right. I think thats what size mine are.

Gravey

iTrader: (3)

55's probably would have been better but I had this set from my other vehicle with only 1 season on them. They are barely used.

Gravey

iTrader: (3)

That site is my favourite too! I have been using it forever!

Silverdollar

Thanks. Got it.