Tire size for new 19's
 

I'm buying a set of 19" OEM Rays for my sedan and since they're staggered I'm not sure what size tires to get. I read through this and a bunch of other threads but I haven't found a solid answer of what the "right" size tires are to get.

This is what I'm thinking:
Front: 225/40/19 at 8" wide
Rear: 245/40/19 at 8.5" wide

I think it would work fine but I'm concerned with the fact that it's just over .5" difference in overall diameter front to back. That's just over 2% which isn't terrible but I don't want to have VDC or big speedo problems. Is there a better size to get on the front?

those sizes are what came on it from the factory.

this info can also be found on the label at the bottom of the drivers side B pillar.

forgot which forum I was in. this would apply to the v35.

what vehicle are you mounting these on?

I'm mounting them on my '07 G35x sedan for summer. It came with 17" alloys so I'm gonna use those for winter.

225/45 & 245/40 Are the stock sizes, stay with STOCK sizes on the X

for v35 stock sizes are 225/40-19 and 245/40-19. this would be for the coupe, as the 19s were not offered for the sedan.

http://www.miata.net/garage/tirecalc.html

play around with that. keep it as close to 26.7 overall diameter as you can.

That's why I said 225/40 and 245/40 because that's 26.1" and 26.7" diameters. 245/40-19 all the way around would be perfect but the 19" Rays are staggered so I think the 245 would be a little wide for the 8" fronts. I also would think a slightly thinner wheel in the front would be desirable.

Is there no "right" size for what I need? Will 225/40 and 245/40 be alright or is there a better option?

Aren't we talking about a V36 X that needs the tires to be as close to the same size as possible? The correct size for the V36 with 19s is 225/45 & 245/40 and it really doesnt matter that the wheels are from a V35

Yeah that's right. I see that size looks real close but there aren't many summer tires available in 225/45/19.

http://www.bigcustomwheels.com/rt_specs.jsp

:biggthumpup:

Thanks for the replies guys. I found that 225/45/19 on 8" and 245/40/19 on 8.5" are the ideal tires but the fronts are very hard to find tires for.

For the record I ended up buying 4 x 245/40 Kumho Ecsta SPT's since I couldn't find a decent set of the ideal sizes.

I thought staggered on an X is a no-no?

I talked to a guy at tire rack and he said all I have to be sure of is that the overall diameter is the same from front to back because the rotational speeds need to be the same when AWD is active. Since the diameters of the wheels are a little different, and I have the same tire sizes on both wheels, the larger wheels will have the tire stretching a little bit further so it will throw off the diameter a couple of eighths of an inch which shouldn't make a huge difference.

Since the AWD is rear-biased, and only will be used substantially in the winter, I think I'll be alright because I have dedicated 17" wheels with winter tires. If the tire diameters are off too much I understand it can cause lots of problems with the transfer case.