16" x >=7" wheels - required offsets
 

Since I'm finding it difficult to track down good tires that will fit on the stock P5 wheels (16x6), I am seriously considering some 16x7 wheels and wondered if the offset rules would be the same as for a 17x7 (required +45, or +48 for a 7.5" width, correct?). Unfortunately, I can't read Japanese so the volkracing site is sorta difficult to understand. ;)

Volk Racing TE-37:
------ 16x7 comes in +42
------ 16x7.5 comes in +42 also
------ 16x8 comes in +42, +46 .. yeah right.
The Protege/Familia is not mentioned under fitments for this wheel at all (for good reason?)

Mazdaspeed MS-Touring:
------ 16x7 comes in +45, +50
+45 is listed as OK for the Sport20.

Mazdaspeed MS-01S
------ 16x7 comes in +33
This is listed as being OK for the Sport20 .. with a big asterix and some comments in Japanese.

OZ F1 cup corsa (on special at oz-boutique.com for 109usd)
------ 16x7.5 comes in +35
This is listed as OK for Protege 5 and MP3.

(Offtopic for this post, but the Crono Evolution is now listed in 17x7 +45 weighing 16.9lbs at 340usd as fitting Protege 5)

How is it that such low offsets (in the 30's) are listed as being a good fit for the P5? And who can get a price on the Mazdaspeed wheels?

It's late and I'm sort of rambling now but I just want to find some wider wheels that will perform well and fit properly.. figured I might as well ask and see what people have to say..

The reason you see people reccommending low offsets is because they don't know any better and do not own this vehicle, I've done so many I can't be wrong.

The Chrono is not available yet but will be shortly. I can get you a club discount on the OZ's although being in Canada may not work out for you.

If you run a 16 it really will come down to the tire size you want to run. It's sometimes easier and sometimes harder.

But as a rule of thumb you were correct when comparing offsets between two wheels of the same width,. Diameter is arbitrary. The only time you can get variance in offset is because tire widths may vary slightly with smaller or larger diameter wheels, i.e. higher or lower profile tires.

Rishie

Tell me the tire size you'd run. I'd run a 215/45 on a +45 or higher in the 7"width. That's a hard one though. Easier to find a +40 and then I'd suggest the stock 195's but that may not work either.

Wow, nice timing! Glad to see I'm actually on-track when looking for wheel specs.

I want the wider wheels to run better tires for autocross so I suppose I'm looking to go as wide as possible without being stupid. The Solo 2 rules for stock class in both the major Southern Ontario series allow for any wheel/tire combination as long as it doesn't extend past the fender. Very lenient!

So .. looking at Kumho V700 .. they have 205/45 and 225/50 in 16's and fit on a 7" wheel. (But then it says the rim-width is 6-8"..) Pirelli PZero also comes in the same sizes.

According to the wonderful tire size calculator (http://www.miata.net/garage/tirecalc.html)
225/50R16 would throw my speedo 5% off. Which I suppose I could deal with for a reasonable tradeoff in grip.

You most definitely cannot run the 225/50. that's way too tall and you want to increase your final drive ratio rather than decreasing it. You want it to accelerate faster rather than adding to top speed for autox.

I'd suggest the 205/45 and you'll be great. This will still be wider and will work awesome. Get the V700s.

Do this, get the continental contisport, it's on special and run the 215/40/16. It has a low treadwear rating and should do quite well.

Get back to me.

Rishie

Thanks for the tip :) Although .. us vs. cdn dollars isn't the best ratio right now. The 215/40 sounds quite appealing.
A sponsor for one of the main autox series in Toronto offers $100 tires to series participants so I may just take advantage of that deal... of course I'd still need to have the wheels for it.

Tirerack says my options for tires are:
- Continental ContiSport (as you mentioned)
- Kumho Ecsta Supra 712
- Pirelli P7000
- Yokohama A520 (Yokohama is a series sponsor)
- BFGoodrich Euro T/A

Unfortunately the Yokohama A032R and the Kumho V700 don't come in that size. :(

Although .. the 'local' OZ distributor has the 17" crono evo wheels listed so if those are available I may consider those and some 215/40/17's

There's no way he has them in stock. But I'd be interested in seeing what you find out.

Thanks, Rishie

Go with the A520's as they're sticky too. just look into the price.