: NEED WINTER TIRES FOR 2005 CADILLAC STS - CAN I PUT 225x55x17'S ALL AROUND???



Detroit Mike
11-22-11, 09:47 AM
HELLO,

I HAVE 2005 CADILLAC STS (REAR-WHEEL DRIVE) AND AFTER HAVING A TERRIBLE TIME LAST YEAR IN THE MICHIGAN SNOW, I AM IN SEARCH OF SNOW TIRES FOR THIS WINTER. MY LOCAL TIRE GUY SUGGESTED FIRESTONE WINTERFORCE (225x55x17) ALL AROUND, HE SAYS ITS A QUALITY TIRE AND NOT AS EXPENSIVE AS BLIZZAKS...MY CONCERN IS THE DIFFERENCE IN SIZE, MY OEM RECOMMENDED TIRE SIZE IS 235x50x17 (FRONT) & 255x45x17 (REAR)...DOES ANYONE KNOW IF THIS SUGGESTED TIRE SIZE (225x55x17) WOULD CAUSE ANY ISSUE AS FAR AS HANDLING OR PLACEMENT ON CAR? ANY HELPFUL INFO WOULD BE APPRECIATED AS I HOPE TO TAKE CARE OF THIS, THIS WEEKEND

aksel79
11-22-11, 10:38 AM
Yes, you will have no issues other than your speedometer will read about 1 mph slow at 60 versus your stock tire size.

I installed the exact setup on my 2005 V8 RWD (Winterforce 225/55 17) a few weeks ago.

Detroit Mike
11-22-11, 10:55 AM
Thanks Aksel79,

What made you decide on the Winterforce and that particular tire size for your STS?

aksel79
11-22-11, 04:34 PM
Mike,

The 225/55 Winterforce are much less expensive than the 235/50 Blizzaks (about half if I recall correctly). Winterforce aren't available in 235/50, my Cadillac dealer recommended them and assured me there would not be any issues. They're only about a half inch larger in diamater than the stock 17's, and a half inch smaller than the fronts on a STS equipped with staggered 18's.

I run 255/45 18's all around in the summer, these are a 1/4 inch larger in diamater than the Winterforce.

The Winterforces do howl just a bit at freeway speeds and the handling is a little floaty at 75-80 but it's about what I expected for winter tires.



Thanks Aksel79,

What made you decide on the Winterforce and that particular tire size for your STS?

JGarten
11-22-11, 10:09 PM
Actually, 55s are way taller than 45s (all else being equal).
Check out http://www.1010tires.com/tiresizecalculator.asp
They recommend <3% difference in tire size.





Stock Tire - 225/45R17 >Search
Tires (http://www.cadillacforums.com/forums/tiresearch.asp?treadwidth=225&profile=45&diameter=17)

Tire 1 - 225/55R17 >Search
Tires (http://www.cadillacforums.com/forums/tiresearch.asp?treadwidth=225&profile=55&diameter=17)










Section Width:

8.85 in

225 mm










Section Width:

8.85 in

225 mm













Rim Diameter:

17 in

431.8 mm










Rim Diameter:

17 in

431.8 mm













Rim Width Range:

7 - 8.5 in










Rim Width Range:

6 - 8 in













Overall Diameter:

24.97 in

634.23 mm










Overall Diameter:

26.74 in

679.19 mm













Sidewall Height:

3.98 in

101.09 mm










Sidewall Height:

4.87 in

123.69 mm













Radius:

12.48 in

316.99 mm










Radius:

13.37 in

339.59 mm













Circumference:

78.44 in

1992.3 mm










Circumference:

84.00 in

2133.6 mm













Revs per Mile:

832.9










Revs per Mile:

777.8













Actual Speed:

60 mph

100 km/h










Speedometer1:

56.0 mph

93.3 km/h







Speedometer Difference: -

Speedometer Difference: 7.084% too slow




Diameter Difference: -

Diameter Difference: 6.62%








Stock Tire - 235/50R17 >Search
Tires (http://www.cadillacforums.com/forums/tiresearch.asp?treadwidth=235&profile=50&diameter=17)

Tire 1 - 225/55R17 >Search
Tires (http://www.cadillacforums.com/forums/tiresearch.asp?treadwidth=225&profile=55&diameter=17)










Section Width:

9.25 in

235 mm










Section Width:

8.85 in

225 mm













Rim Diameter:

17 in

431.8 mm










Rim Diameter:

17 in

431.8 mm













Rim Width Range:

6.5 - 8.5 in










Rim Width Range:

6 - 8 in













Overall Diameter:

26.25 in

666.75 mm










Overall Diameter:

26.74 in

679.19 mm













Sidewall Height:

4.62 in

117.34 mm










Sidewall Height:

4.87 in

123.69 mm













Radius:

13.12 in

333.24 mm










Radius:

13.37 in

339.59 mm













Circumference:

82.46 in

2094.4 mm










Circumference:

84.00 in

2133.6 mm













Revs per Mile:

792.3










Revs per Mile:

777.8













Actual Speed:

60 mph

100 km/h










Speedometer1:

58.9 mph

98.1 km/h







Speedometer Difference: -

Speedometer Difference: 1.864% too slow




Diameter Difference: -

Diameter Difference: 1.84%

aksel79
11-22-11, 11:06 PM
Right, my summer rims are 18's. A 255/45 18 is about 3/4 inch taller than the stock 235/50/17. Edited my post above, originally indicated the summer tires were 245/45 18.



Actually, 55s are way taller than 45s (all else being equal).
Check out http://www.1010tires.com/tiresizecalculator.asp
They recommend <3% difference in tire size.





Stock Tire - 225/45R17 >Search
Tires (http://www.cadillacforums.com/forums/tiresearch.asp?treadwidth=225&profile=45&diameter=17)

Tire 1 - 225/55R17 >Search
Tires (http://www.cadillacforums.com/forums/tiresearch.asp?treadwidth=225&profile=55&diameter=17)










Section Width:

8.85 in

225 mm










Section Width:

8.85 in

225 mm













Rim Diameter:

17 in

431.8 mm










Rim Diameter:

17 in

431.8 mm













Rim Width Range:

7 - 8.5 in










Rim Width Range:

6 - 8 in













Overall Diameter:

24.97 in

634.23 mm










Overall Diameter:

26.74 in

679.19 mm













Sidewall Height:

3.98 in

101.09 mm










Sidewall Height:

4.87 in

123.69 mm













Radius:

12.48 in

316.99 mm










Radius:

13.37 in

339.59 mm













Circumference:

78.44 in

1992.3 mm










Circumference:

84.00 in

2133.6 mm













Revs per Mile:

832.9










Revs per Mile:

777.8













Actual Speed:

60 mph

100 km/h










Speedometer1:

56.0 mph

93.3 km/h







Speedometer Difference: -

Speedometer Difference: 7.084% too slow




Diameter Difference: -

Diameter Difference: 6.62%








Stock Tire - 235/50R17 >Search
Tires (http://www.cadillacforums.com/forums/tiresearch.asp?treadwidth=235&profile=50&diameter=17)

Tire 1 - 225/55R17 >Search
Tires (http://www.cadillacforums.com/forums/tiresearch.asp?treadwidth=225&profile=55&diameter=17)










Section Width:

9.25 in

235 mm










Section Width:

8.85 in

225 mm













Rim Diameter:

17 in

431.8 mm










Rim Diameter:

17 in

431.8 mm













Rim Width Range:

6.5 - 8.5 in










Rim Width Range:

6 - 8 in













Overall Diameter:

26.25 in

666.75 mm










Overall Diameter:

26.74 in

679.19 mm













Sidewall Height:

4.62 in

117.34 mm










Sidewall Height:

4.87 in

123.69 mm













Radius:

13.12 in

333.24 mm










Radius:

13.37 in

339.59 mm













Circumference:

82.46 in

2094.4 mm










Circumference:

84.00 in

2133.6 mm













Revs per Mile:

792.3










Revs per Mile:

777.8













Actual Speed:

60 mph

100 km/h










Speedometer1:

58.9 mph

98.1 km/h







Speedometer Difference: -

Speedometer Difference: 1.864% too slow




Diameter Difference: -

Diameter Difference: 1.84%

Detroit Mike
11-23-11, 08:42 AM
Hey guys,

Thanks for your reply, actually I made a mistake in my original post...my rear OEM tire recommendation is 255x45x17

JGarten,

Thanks for the tire comparision website, I used this and both my OEM recommended tire sizes (front & rear) are less than 3% difference in diameter/height

I will go ahead and try the Firestone Winterforce and reply back with my opinion once the snow falls...wish me luck! lol