Is the 205/55-15 comparable in size to the stock 195/55-16? I'm wanting to make this switch but want to keep gearing effect/ speedo error to a MINImum.

 

Yes, 205/55 R15 is the closest to stock tire size of the 205 width (which is what I'm using). RallyMINI runs 205/50 R15 which results in .5" lower ride height and what effectively amounts to a gearing advantage since the tire diameter is nearly an inch shorter.

edit: typed too fast the first time and left the decimal point out.

 

Here is a sample of the speedo readings.....first column is the 195/55 the second is the 205/55....the last is the difference

5 mph (8.04 kph) 4.91 mph (7.90 kph) -0.09 mph (-0.15 kph)
10 mph (16.09 kph) 9.82 mph (15.80 kph) -0.18 mph (-0.29 kph)
15 mph (24.13 kph) 14.73 mph (23.70 kph) -0.27 mph (-0.44 kph)
20 mph (32.18 kph) 19.64 mph (31.60 kph) -0.36 mph (-0.58 kph)
25 mph (40.23 kph) 24.55 mph (39.50 kph) -0.45 mph (-0.73 kph)
30 mph (48.27 kph) 29.46 mph (47.39 kph) -0.54 mph (-0.88 kph)
35 mph (56.31 kph) 34.37 mph (55.29 kph) -0.63 mph (-1.02 kph)
40 mph (64.36 kph) 39.27 mph (63.19 kph) -0.73 mph (-1.17 kph)
45 mph (72.41 kph) 44.18 mph (71.09 kph) -0.82 mph (-1.31 kph)
50 mph (80.45 kph) 49.09 mph (78.99 kph) -0.91 mph (-1.46 kph)
55 mph (88.50 kph) 54.00 mph (86.89 kph) -1.00 mph (-1.61 kph)
60 mph (96.54 kph) 58.91 mph (94.79 kph) -1.09 mph (-1.75 kph)
65 mph (104.58 kph) 63.82 mph (102.69 kph) -1.18 mph (-1.90 kph)
70 mph (112.63 kph) 68.73 mph (110.59 kph) -1.27 mph (-2.04 kph)
75 mph (120.67 kph) 73.64 mph (118.49 kph) -1.36 mph (-2.19 kph)
80 mph (128.72 kph) 78.55 mph (126.39 kph) -1.45 mph (-2.33 kph)

Mileage differences
1 mi (1.61 km) 0.98 mi (1.58 km) -0.02 mi (-0.03 km)
5 mi (8.04 km) 4.91 mi (7.90 km) -0.09 mi (-0.15 km)
10 mi (16.09 km) 9.82 mi (15.80 km) -0.18 mi (-0.29 km)
50 mi (80.45 km) 49.09 mi (78.99 km) -0.91 mi (-1.46 km)
100 mi (160.90 km) 98.19 mi (157.98 km) -1.81 mi (-2.92 km)
500 mi (804.50 km) 490.93 mi (789.91 km) -9.07 mi (-14.59 km)
1000 mi (1609.00 km) 981.86 mi (1579.82 km) -18.14 mi (-29.18 km)
5000 mi (8045.00 km) 4909.32 mi (7899.09 km) -90.68 mi (-145.91 km)
10000 mi (16090.00 km) 9818.63 mi (15798.18 km) -181.37 mi (-291.82 km)
50000 mi (80450.00 km) 49093.16 mi (78990.89 km) -906.84 mi (-1459.11 km)
100000 mi (160900.00 km) 98186.31 mi (157981.78 km) -1813.69 mi (-2918.22 km)

RPM @ 4000RPM would be 3927 RPM with the 205/55

this is just an example of the RPM difference. I chose 4000rpm cause its about in the mid ranged.

 

heheheh not a 5 inch difference.....a 0.5 inch difference

 

Thanks.

 

Appreciate the info!

 

215/55-15 is the closest to the stock 16". A 205/55-15 is 97.7% of the stock dimension; a 215/55-15 is 99.5%. A little bit harder size to find but still lots of good choices.

 

A 195/55-16 is 24.44". Holeys with the stock 175/65-15's are 23.96, almost a half inch shorter. 205/55/15's are pretty close to that at 23.88". I think you'd be fine anywhere from about 23.5 to 24.5. I wonder what size is actually the most accurate, speedometer-wise?

 

I'm so tempted to get these, such a nice price for some hot wheels. I'd have to space out the rear a little.

 

They really are nicely offset, it would only take a small spacer to make them poke....I plan to install them (when my snow tires retire) and just measure to see how much more i need.

 

AFter I get some coilovers, this may seriously be considered. I love 'em on you're car.

 

I saw someone asked about 225 width tires; I'm contemplating this route, as well (225/50 or 225/45, I suppose). I want the width for looks, but I also don't want any rubbing or clearance issues. The suspension's stock and I won't be changing springs, but I'll be doing track days and maybe an autocross. Thoughts?

Don't forget the Miata.net tire size calculator. Doesn't help with fitment issues, however. :-)

 

blalor, I've been trying to work out some calculations as to whether or not 225's will fit on Rewinds with a stock suspension. 225/50 is about the right diameter. 225/45 for auto-x. I figured that the lower offset (as opposed to S-Lites) should nearly cancel out the extra width of the wheel...maybe 2-4mm extra clearance needed. This shouldn't be a problem - the front is tight but it should work. The outside is another story. You'll probably need an extra 15-20mm clearance on the fender side. This is the part I don't know about.

If you decide to give it a try, post back with your experiences.

 

If it helps, I use 225/45-16 Avons on 15x7 Kosei K1-Rs (38ET) with no rubbing or other issues. Car is lowered with Bilstein PSS9s.

Scott
90SM

 

Er, you run 16" tires on 15" wheels? How's *that* work? ;-)

So the additional 2 (2 *what*? mm?) of offset with the Rewinds moves them further into the wheel-well, is that right? How much is your car lowered? If I got the formula correct, the 225/50s are about 11.25mm taller than 225/45s, and would be about 5.6mm closer to the inside of the fender. That's not a whole lot, so I *think* they'd still work...

Thanks for the info, Scott!

 

Doh! Thanks for pointing that out Blalor. Guess I'm too used to typing 215/45-16 Azenis after 5 years running them.

The tires I was referring to are of course 15", which wouldn't be so loose on 15" wheels as the original post would imply.

Ride height gets a touch tricky, since that wheel/tire set isn't on the car right now. Last measurements taken were with the Bilsteins set to the middle of their recommended range, and with 205/50-16 (carefully typed!) Arctic Alphin tires installed, down to about 5/32 tread depth. Car currently has been adjusted to the top of the recommended range (spring perch up 10mm from previous setting), and that is the setting that I've been using with the 225/45-15 Avon Tech Rs. It's a bit cold right now to install those tires, but I'll be updating measurements when it warms up a bit.

Measured in the center of the front air dam (lowest point on car) - 2 1/2" between ground and air dam. Note that material has been worn away across most of the face of the air dam.

Measured between the ground and the bottom of the lifting blocks on each side of the car - 4 3/8" in front and 4 15/16 in rear.

For what it is worth, the 205/50-16s with the latest adjustments are still tucked into the top of the wheel well a bit.

Convoluted, but again I hope that helps.

Scott
90SM

 

Argh. Ok, I bit the bullet and ordered from a local Discount Tire. The wheel price was very good ($95), the tires just so-so ($105) for 225/50/15 Yokohama AVS ES100. Grand total's about $900, which was more than I wanted to spend, but I'm tired of agonizing about this. :-)

I'm *really* hoping the 225s aren't a mistake; from what 90STX and others have said, it shouldn't be a problem, but both DT stores I talked to looked at me like I had a third head when I specified that size. I'm more concerned about rubbing on the struts than height. 225/50/15 are about 0.4" shorter than the stock 205/45/17. I chose the size in part because of tire selection and partly because of appearances; I think the stock 205s look a little skinny. I'm going to have a pit in my stomach until these things are mounted; I don't really want to lay our $400 for tires I can't use.

 

You could always get thin spacers to push them out a hair if you need too.

[fingers crossed for you]

 

Thanks, DiD. :-)

 

Any pics of the rewinds in 16"?

 

Nope. They only come in 15"

 

Let us know how it works out! I've wondered about this combination as well.

 

Me too.

 

I guess I'll be a guinea pig for y'all. ;-) Gotta give back to the community *somehow*, right?

 

blalorr: Are you gonna have the new shoes in time for next week's riverboat run?