I did try to search on this first but was getting errors, so I'll post, sorry if it is a repeat, and if so, please point out the thread, I am up for reading...
I need to get new summer tires for my 17X7 rims. There are some good selections out there, I like the Kumho SPTs from TireRack, but the 225/50 are $107 each, and the 225/45 are $90 each (thats almost a $70 savings). I spoke to Gary at TireRack, he first said no, but talking a little more, he said if you run them at 36psi, they should be fine. So, is there anyone out there that runs 225/45 on 17X7 rims and doesn't have a problem? Agrees, disagrees, etc.

Thanks,

JimL
'00 SE, 5 spd (3%)

 

did you check the wheel/tire sticky in here?

 

http://forums.maxima.org/showpost.ph...7&postcount=71

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

http://forums.maxima.org/forumdisplay.php?f=53

 

I did look at the sticky, but it only seemed to be 18" and 19" wheels. I have aftermarket 17X7", unless Soonerfan was talking about a different sticky. I was hoping for more a post specific to tires (searched for that too, and could find anything for Kumho SPTs)?
The thread: http://forums.maxima.org/showpost.ph...7&postcount=71
from PuppetMater was helpful, and the Kumho SPT 225/45 R17 comes with a 94Y (so does the Sumitomo HTR Z III, which seems decent as well) rating, so it is above the minimum 91 rating suggested for a tire with a larger aspect ratio, but I wonder if the wheel would be too stiff, so it would be harder to mount, or is the larger load rating working in my favor?

Thanks,

Jim

 

They'll fit. Exact same size I have on my old 17x7 wheels.

 

Thanks, I just got an email from Gil @ TireRack, he said, "That size would work fine for the reasons that you mention. People have used that size for years on the car you have listed."
I will order them.

Thanks,

Jim

 

They'll fit fine, but IMO, wont look so good. They will leave some wheelgap. They need to be wider & a tad taller, IMO of course.

 

I agree, but then again, that tire size is about as close to stock as you can get. (so as not to throw off the speedo)

Since he's already got wheels that are 17x7, that's about the best tire size IMO. Any wider on that wheel would start to bulge alot and you wouldn't really benefit from the added width...

 

You do realize that this is an A33, which came w/ 225-50's OEM?

 

You caught me...
thinking of the A32 stock tire size

 

According to the tire calc, a 225-50-17 would be closer to the stock tire size for an a32. It's only like .6% off, whereas the 225-45-17 would be about 2% off.

Correct?

 

What size are you using for the stock A32 size? IIRC there are a couple sizes depending on year/trim.

My 97 SE had a stock size of 215/55-16. In this case, 225/45-17 is off by 1.35% whereas the 225/50-17 is off by 2.13% At 60MPH the 225/45 would be at 60.8 and the 225/50 would be at 58.7

My old 95 gxe I think had a stock size of 205/60-15. In this case, the 225/45 is still the best choice at 1.17% off and the 225/50 is off by a whopping 4.73%

http://www.1010tires.com/TireSizeCalculator.asp?

 

Seems a little now re: A33 / A32?

 

Sorry, next time I'll create a new thread for two posts worth of discussion.

 

I'm just in a bored mood . I sued to rock 225-45-17's on my 32 back when. I like the way 235-40 -18 looked / felt more though. Then I upgraded to 245-40-18's on the A32. Looks real nice. Now I rock 235-45'17's.

 

Yes, the OEM was 225/50. First the info from a sticky thread on the subject:

"225/45R17: This tire size is in spec on 7.0"-wide rims. It produces a speedometer error of 3.4%. This error slightly exceeds the recommended maximum speedometer error of 3.0%, but is close enough to be considered acceptable. Load ratings for this tire will normally be less than that of the 225/50R17 (load rating 93). Be certain that the tire you select has a load rating of 91 (1,356 pounds) or higher. This tire has a lower profile than the 225/50R17 and will therefore produce a less compliant ride and a wider fender gap than the 225/50R17."
as per this link: http://forums.maxima.org/showpost.ph...7&postcount=71
That PuppetMaster pointed to (thanks for that info)
As for the speedo error, mine is already in error, just today on the way to work, on a side street, I was keeping it at exactly 30mph, and the radar speed cart (the one on the trailer that posts your speed) said 25.

Here are my thoughts:
a 225/45 is a stiffer sidewall than a 225/50. Looking at the calculated numbers from: http://www.rojawheels.com/wheeltech/...Calculator.htm
*simple, easy, and cool calculator, btw*
The 225/50: tire diameter=25.85 in., tire width=8.85 in., and the tire sidewall height=4.43in.
The 225/45: tire diam=24.97 in., tire width=8.85 in., and the tire sidewall height=3.97in.
So, the difference is 1" in diameter, and .5" in sidewall height. The car drops .5" lower to the ground, and the wheelgap would increase .5".
Performance is my goal, not looks, so I am ok with the wheelgap as a trade off to a lower center of gravity, stiffer sidewalls (which would compliment my Illuminas), and the a price difference of $17 for each tire (as per TireRack, $90 for 225/45s vs $107 for 225/50s).
Does anyone see flaws with those calculations, reasons, etc.?

Thanks,
JimL

 

As long as you're fine with the 3.4% speedo difference, go for it. I'd do the same.

224/45 will also probably be a lighter tire, and since it's smaller in diameter too, acceleration could benefit. Probably won't be noticeable, but technically it could help.

 

I'm coming from stock 15" steelies (96 gxe).

So I'd be better off having 225-50-17 correct? Basically it creates the lowest difference in the speedo, and doesn't have as much of a wheelgap. (very small amount, I know)

Wouldn't it be the same weight though? 50 and 45 just refer to the percentage of the tire that is the firewall, correct? Or am I way off?

 

from 15" steelies, the 225/50 will throw your speedo off more than 3% You want 225/45-17.

As far as weight, go look on tirerack. Compare the SAME TIRE in sizes 225/45-17 and 225/50-17. Most tires will probably show about a pound difference between the two sizes. The 225/45 has the same dimensions, with a smaller sidewall. That means less total rubber than the 225/50 and therefore typically a bit less weight.

 

Negative. Going from 205-65-15 to 225-45-17 is 2% too fast

Going from 205-65-15 to 225-50-17 is 1.4% too slow.

I just did it on the miata calc.

 

That's because I'm retarded and put 205/60-15 in for the calc, then stated 205/65 when I meant 205/60 and 205/60 is just the wrong size to begin with.

You're correct; 225/50-17 would be best comming from 15" steelies.
From 16" SE wheels, 225/45-17 would be best. (unless I'm just completely stupid today)

 

Ah, that makes more sense. I thought I was taking crazy pills or something.

Thanks for the help and sorry to the OP for the hijack!!

 

Ok, so my choice was the Kumho SPTs , 225/45R17, $397 shipped, I ordered on the phone Friday, and they were supposedly shipped that day.

 

Good deal! Let us know how the Kumhos are!