borgit

Hey guys, I'm approaching 50k miles on my stock MXM4 Michelins and the time is soon coming to replace them. I'm thinking of going with the slightly wider 245's, but can't decide wheather i should go with the 40's or the 45's. Any suggestions are appreciated.

Thanks.

Turbonut

iTrader: (1)

It boils down to personal preference. The stock 235 tire has a diameter of 25.3" and the 245/45 is 25.7" which will fill the wheel slightly more, my personal preference. As the 245/40 is only 24.7" (1/2" smaller) in diameter, it will make the wheel well opening appear larger with the smaller tire.

stillhere153

iTrader: (1)

the 245/45 is slightly larger in diameter so it will affect the speedo reading slightly, like 2% difference from stock diameter

anything above 3% is concidered unsafe

245/40 vs 245/45 is all about looks and ride comfort

if you do chose a 245/45 make sure the sidewall is reinforced or you will feel like the sidewall is mushy on corners... if you don't drive aggressively you will not even know the difference

anx1300c

iTrader: (2)

I went with 245-45-17 Potenza 960's and I'm happy with my decision, aside from the 2 mpg decrease. They're much better in the wet and dry than the OEM Turanzas, but they're like skis in the snow, at least until I get going. I like the slightly more aggressive look as well.

I hate cars

245/45 or 255/40 should be your only considerations.

A 245/40 will be way too short. Even a 255/40 is just a little smaller diameter.

stillhere153

iTrader: (1)

I disagree
245/40-17 is closer to 235/45-17 than 245/45-17

I hate cars

Not exactly. You be the judge:

235/45= 25.33"
245/40= 24.72"
245/45= 25.68"
255/40= 25.03"

Turbonut

iTrader: (1)

Looks like the closest is a 245/45-17

stillhere153

iTrader: (1)

aaah crap.. I got screwed up because of the damn tsx... for me

Inaccurate

Might not be recommended. But, why unsafe ? I am running 235/40-17. They are 24.4" when new, and as they wear that goes down to 24.0". Right now with the new tires at 24.4", my speedo is off by 4-5 MPH (verified with Escort 9500i). I have no problems. I even hit ABS and VSA (traction control) often. Both ABS and VSA perform normally.

Bearcat94

I've got 245/45-17. Besides cost (which knocked the 255/40 out), I wanted the fender filled a bit more. It does so by ~1/4 inch.

But also keep in mind that if your current tires are worn, the new tires will have ~8/32 more tread - another 1/4" - so at first the tire will look to have a very tall side-wall. You get used to it pretty quick and you'll wear off that "extra" 1/4" over time.







As long as all the tires are pretty much the same diameter, VSA, Speed Sensors, etc should function just fine. If the diameter gets off too far (how much is too much? ) it might be possible to affect the suspension geometry.

I hate cars

But 255s are better!

Turbonut

iTrader: (1)

borgit

Guys, thanks for all the tips. I've thought about the 255 tires, but officially you need atleast 8.5" rim for those. It seems like the 245 45R17 is the best bet for the OEM rim. Next question is what do you think about the Michelin Pilot Sport A/S Plus tires? Last I checked they go for about 180 per tire on tirerack and for all that i read, they seem like the best A/S tires on the market.

Bearcat94

I've got 2 or 3 months on them and they are great so far. Good wear, 45k warranty (which is unbeatable in this category), MUCh stickier than the stock OE tires, pretty quiet and comfortable.

Can't say what'll happen at 15, 20 or 25 thousand miles; hopefully they will continue to perform as well as now.

anx1300c

iTrader: (2)

No.

The 255 is 3/10 shorter while the 245/45 is 3.5/10 taller. Close though...

Turbonut

iTrader: (1)

That's true, but the OP wasn't asking about the 255 so I eliminated thast size.

Turbonut

iTrader: (1)

Although the OP wasn't asking about the 255/40, my wheels started turning, so rather than using the tire size calculator, thought I would check the actual specifications listed as I've gone through this before:

Yokohama S.4
245/45 25.7 +.2
235/45 25.5
255/40 25.1 -.4

Michelin Pilot A/S Plus
245/45 25.7 +.3
235/45 25.4
255/40 25.0 -.4

Bridgestone 960
245/45 25.7 +.3
235/45 25.4
255/40 25.0 -.4

I hate cars

It's amazing the difference in diameter and width between the same size tire.

Bearcat94

Especially width.

Michelin MXM4 235/45-17 is the same tread width as Michelin Pilot Sport AS Plus 245/45-17.

And the Bridgstone 960 AS is nourtoriously narrow at a given Section Width compared to most competitors.

Turbonut

iTrader: (1)

Great points as most don’t realize how tires in a specific size and be so different in width/diameter.

Here’s a prime example of 245/45-17 tires:

Bridgestone 960/Yokahama W4s
Diameter 25.7/25.7
Section width 9.4/9.7
Tread width 8.2/9.2

anx1300c

iTrader: (2)

Don't forget weight differences too. My 245/45-17 960's are pigs at 29lbs vs 24 lbs for the OEM tires. Bet I would've broken 100 mph in the quarter pretty easily with the Turanzas.

antlive

looking to purchase the Bridgstones Polo Position 245/45/17, wondering if anyone has a better price than tirerack?