Nicki

Please does anyone know if it matters if I put the P245/45/17 vs the P235/45/17 which came with the car on the stock 17" wheel? Is it safe to change from "P235" to "P245"?? what differences should I expect between the two sizes with the cars performance? Thank you for your opinions.

narnia

Nicki it might not work. Tirerack.com explains what that number indicates. They give as an example:

P225/50R16 91S

The 225 indicates this tire is 225 millimeters across from the widest point of its outer sidewall to the widest point of its inner sidewall when mounted and measured on a specified width wheel. This measurement is also referred to as the tire's section width. Because many people think of measurements in inches, the 225mm can be converted to inches by dividing the section width in millimeters by 25.4 (the number of millimeters per inch).

225mm ÷ 25.4 = 8.86"

2obsessed

You can call the tire rack. They usually know all the combos that will fit - they are really knowledgeable.

rets

Have you done the search for this yet? There are lots of threads talking about this. For example,

Pirelli P Zero Nero M+S

some about 235 vs 245...

rkilian

I have the 245/40/18 rather the the Acura 235/40/18. I also have the Eibach springs (1"lower) the car does not rub. For me, It worked wonderfuly. To quote the math, 245-235 is 10 mm. x 45% is 4.5 mm; that's less than 3/16", I think the difference in the speedo is less than 3 MPH. the 245 covers the wheels against curb rash much better than the stock 235. If it was me, I would (did) go with the 245. but that's just me.

KJSmitty

YES

The 245/45 is just slightly larger in diameter and width - and I mean "slightly". At least 2 or 3 (that I have read) folks on this sight are running 245/45.

I compared 255/45 and 245/45 and the factory 235/45's the other day at the tire shop. I'm still heavily considering the 255's but would want to mount one and try it front and back on the car to check looks/clearances

Chuck

The difference between 235 and 245/45 on the P Zero Neros is .2 inch. 5 revolutions per mile. You wouldn't probably even notice.
The load rating is not as high on the 245, 1,500 lbs vs. 1,750 or something like that. The 245 may actually ride a little softer then the 235... I don't know.

Mav

Thats good information Chuck...thanks! BTW...Welcome to the forums.

Now let me ask the stupid question...isnt the 245 the width of the tire and 45 the aspect ration or percentage of width? My math may be a little rusty but 245 mm is 9.545669291338583 inches which would appear to be the width of the tire and not the height. What am I missing?

Oh sorry I see that was already addressed...I will go back to sleep now.

Chuck

haha. Yeah, you're right about the size. I think I'd go with the 245's as well.
Thanks for the welcome. I have a 2003 TL-S that I purchased in April 2002. I've been a long-time List-Lurker, but recently started to post some. I'm waiting for a new 2004 TL, 6MT, SSM/Quartz w/ Navi. I'll probably be waiting for awhile.

Tread

Chuck is correct, only 0.2" difference in overall diameter. That is fine for spedo.

The load rating is fine also, stocks are 1433lbs (the 93 in the 93W rating on the tire, the W is speed at 168mph, so just make sure load rating is 93 or greater), or there abouts, so anything over is fine.

99WDP

Here's a tire size calculator for those that don't already have one.

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

KJSmitty

SWEET!

mrtech

Do you think we can put 50 series tires instead of 45 series tires on the 17"s? What width would that be (if even possible)? I figure the ride will be a bit softer but the cornering a bit penalized.

fsttyms1

id do a 255/40

Mav

I second that...thats about a 9 on the kickbutt-0-meter.