Cadillac Owners Forum banner

1 - 8 of 8 Posts

·
Registered
Cadillac
Joined
·
7 Posts
Discussion Starter #1
I have a 04 luxury sport CTS with 17" wheels. Came equiped w/ the Goodyear RSA's(225 50 17). Time for a tire change but wantd more 'traditional ride" so I've opted for the slightly larger size sidewall 55 and wider 235. everything fits fine...fills out the wheel wells and NO clearence problems. Took out the sharpness of the stiffer and shorter RSA's and still handels well. Those looking for everyday drivability and performance might want to consider this.

Cheers / Bryan :)
 

·
Registered
2005 CTS 3.6L, 2006 350Z, Ducati 996s
Joined
·
2,449 Posts
I have a 04 luxury sport CTS with 17" wheels. Came equiped w/ the Goodyear RSA's(225 50 17). Time for a tire change but wantd more 'traditional ride" so I've opted for the slightly larger size sidewall 55 and wider 235. everything fits fine...fills out the wheel wells and NO clearence problems. Took out the sharpness of the stiffer and shorter RSA's and still handels well. Those looking for everyday drivability and performance might want to consider this.

Cheers / Bryan :)
Just remember that you changed the rolling diameter, your speedo is going to be off
 

·
Registered
2009 3.6DI radiant CTS fully loaded
Joined
·
577 Posts
Ummm.... Hope you won't find your self getting a ticket for driving too fast when thinking you're at the right speed....

Get it fixed ASAP
 

·
Registered
Cadillac
Joined
·
7 Posts
Discussion Starter #5
here is what the dimension calculator says:

225 50 17 235 55 17

sidewall 4.43 5.09

width 8.86 9.25

diameter 25.86 27.18

circumfrence 81.24 85.38

if spedo is reading 65 calculation is 68.23 for example. the higher the speed the bigger the spread.
Also if weather clears here tomarrow i'll post a few pics

Rgds, Bryan
 

·
Registered
2003 CTS Manual Trans., '93 STS
Joined
·
3,035 Posts
I wouldn't worry too much about the speedo. My experience is that it's actually calibrated for the V size tires (1" taller than stock CTS tires), as corroborated with a GPS. After swapping to 245/45R18's (26.7" dia) the speedo is now spot on. 235/55R17's are about 0.5" taller than the V tires, so you'll be closer than with the stock tires! Heck, tread wear during the life of a tire will affect it over 0.5"! Just make sure you leave yourself a little margin when cruising at 75mph down the highway!

With members mounting 22's on their CTS's, I don't think putting 235/55R17's on to soften the ride and fill the wheelwells is such a big deal. Rolling diameter or not. Remember, those calculators are for total diameter, not rolling radius, which is with the car on the tires. Taller sidewalls flex more than lower profile tires, which makes the rolling radius smaller than calculated. You'll be fine.
 
1 - 8 of 8 Posts
Top