It's already one thing that the car is driving more than 2 mph faster than usual(58.4 mph when my speedo says 60), I was cruising with the speedo reading 80, when I was really only going about 75.....This was confirmed the other day when I and SLYTL were driving home from the CT meet....his car read 75(on his stock TLS rims/tires) while my car read 80 mph(check sig for info)
Ed

 

That is the main reason why I didn't want to go with 225/45-17. The wife racks up enough miles on the car Surely don't need to add more than the actual. But honestly I know how you feel Ed!

 

This is also a good thing. When you think you're going fast, you're actually only going 5 mph slower. Good for when encountering cops!

 

Shoof, all the more reason to switch to 235/45/17's. I've had them on for a couple of K now, and they are fine, fast acceleration, hard cornering, 60ft. slalom, they went through all of that with flying colors, all on stock rims.

 

See Ed i told you the 235's would be ok! lol :p

 

to fix this problem wouldn't you have to get a tire with a different aspect ratio? stock TL wheels have a total diameter of 25.6 - 25.7 inches....to keep the make sure you're going the same speed as what it says on the speedo you'd need a wheel/tire combo that has the same overall diameter? I'm not too sure about this.......is this right?

 

Take note of the width of your rims. The wider the tire and the lower the tire profile, the wider the rim width is required.

 

shoof didnt you know that BEFORE you got those tires?

if it didnt affect the speedo id have some S rims on my car right now

cant you recalibrate the speedo?

 

I knew it would affect the speedo, but I didn't think it would be that much of a difference!
Ed

 

I thought if your diameter was smaller than stock, than your car would be going slower than what it appeared on the speedo, and vice versa.

 

fahoumh, yes you need to get a tire with the same overall diameter/tire-height.

ZodiakTL, you fit 235/45/17's on your stock TLS rims? (6.5"?) If so, maybe it's time to get some Potenzas on mine. I would really like to get 18s or 19s, though.

 

You can go 235's on a 6.5 inch rim without much of a problem.... For a 7" wheel (like my CLS wheels) it's safe to say you can do 235's with no problem, and go as wide as 245(or 255, if you got the ball$)
Ed

 

Hmmm 245/45/17 is EXACTLY the same OD as our stock 205/60/16's......That's a thought....
Specification Sidewall Radius Diameter Circumference Revolutions Difference
205/60-16-----4.8 in---12.8 in----25.7 in----80.7 in--------785 / mile 0.0%
225/45-17-----4.0 in---12.5 in----25.0 in----78.5 in--------808 / mile -2.8%
235/45-17-----4.2 in---12.7 in----25.3 in----79.6 in--------796 / mile -1.4%
245/45-17-----4.3 in---12.8 in----25.7 in----80.7 in--------785 / mile -0.0%

 

215/50/17 are a close fit, although there are only 3 brands of performance tires that are made with these dimensions. I asked a honda mechanic about this dilemna this past weekend and he said that I shouldn't worry about it too much, because he speedometer is never 100% precise anyways.

 

I just realized something, u guys are talking about the TL, not TL-S. With TL-S tire dimensions, the 235/45/17's come out to be only a .54% difference from stock.

 

what ratio do you need for 18x7.5??