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Recommended Posts

Posted

Hi there

i need help, in my Country is dificult to find tires sizes and good quality, and i have on my 04 cayenne turbo 275/40/R20 and i only find 275/45/R20 you think i going to have any problem with this sizes of tires? can i used this tires? im not using the tire presure sensor.

thanks

Posted (edited)

Hi -- there are many discussions about Cayenne tires, sizes, etc, here on the forum.

This discussion may be of interest (Loren posted revised official tire specs) but be sure to search and you'll find a ton of info like size difference and how that may impact your speedometer -- in your case what a sidewall height difference will introduce if you go with the 45/20 instead of 40/20.

I just searched for you and this discussion has the tire-size difference calculator. See attached pic for your info. Your speedo will be around 4% too slow. Depending on how you drive and if you go off-road (and if you have air suspension which I think you do because you have the Cayenne Turbo) you'll need to consider internal wheel-well issues such as scraping but overall I think you'll be OK.

Hi there

i need help, in my Country is dificult to find tires sizes and good quality, and i have on my 04 cayenne turbo 275/40/R20 and i only find 275/45/R20 you think i going to have any problem with this sizes of tires? can i used this tires? im not using the tire presure sensor.

thanks

post-41432-0-91038500-1300985441_thumb.j

Edited by odix
Posted

I did it. I went from 275/40/20 to 275/45/20. The ride has a little more cusion with the higher sidewalls but the handleing has suffered slightly. If there was not another option I would probably not do it again. I also went with the nexen rodian for cost but the continentals were MUCH stickier on the road but wore out faster. Also, when I pass the police radar that shows the speed you are going my speedometer and the radar are both the same.

  • 1 year later...
Posted

I did a lot of research on the 20" staggered rims and the tires that fit them and just wanted to get some information about this in the forums. My goal was for the tires to be a little bigger in diameter than stock. I've always felt the 20" stock tires leave too much wheel well exposed. Seems everyone is going with either 275/40r20 all around, or 275/40r20 in front and 315/35r20 in the rear, or the slightly larger 295/40r20s all around. I decided to try 275/45r20s in the front and 295/45r20s in the rear. It's great!!! It fills the wheel wells better and is wider, 0.8", and a little taller, 0.7", in the rear than in the front. It's the best fit for the rims and the best look for my taste. I also consulted my local Porsche dealership and the mechanics told me the difference in diameter would not be an issue as long as they were not on the same axle. So, in summary the 275/45r20s front and 295/45r20s fit great but they are not listed as a compatible size.

I'm not sure if I know how to post a picture, guess I'll find out when I press "Post".

  • 4 weeks later...
Posted

hey dervin1968 and swflhomes,

were you able to figure out how to post those pics. I am contemplating this same idea. I purchased my wife an 04 CS 6 yrs ago with 20 inch sport design wheels and 275/40/20 tires.

It continues to be a great suv and family car, will probably get her a 2011 CS next year, but for now I am about to move on to my 3rd set of tires. 1st I had oem Conti's on it, and now Hankooks Ventus

with about 20k miles on them. Hankooks are not absorbing the bumps very well any more and getting louder. The car still handles great, but just getting tired of the hard tire slaps and bumps

on our crappy freeways out her in los angeles.

I was thinking of going with a taller diameter with 275/45/20, vs the stock 275/40/20, and that it would add a more supple ride. Since my wife drives the car 99% of the time, I don't think she

will notice a loss of canyon driving handling. I also wanted the wheel well fender gap filled a bit better too for better looks.

I noticed swflhomes mentioned he would not do it again... bummer. if either of you could expand on that or supply pics that would be very helpful.

right now, if I stay with original size I hear the hankooks "AS" all season are a lot quieter. any thoughts?

Posted (edited)

Stock Tire - 275/40R20 Search Tires

Tire 1 - 295/40R20 Search Tires

Tire 2 - 315/35R20 Search Tires

Section Width: 10.82 in 275 mm

Section Width: 11.61 in 295 mm

Section Width: 12.40 in 315 mm

Rim Diameter: 20 in 508 mm

Rim Diameter: 20 in 508 mm

Rim Diameter: 20 in 508 mm

Rim Width Range: 9 - 11 in

Rim Width Range: 10 - 11.5 in

Rim Width Range: 10.5 - 12.5 in

Overall Diameter: 28.66 in 727.96 mm

Overall Diameter: 29.29 in 743.96 mm

Overall Diameter: 28.68 in 728.47 mm

Sidewall Height: 4.33 in 109.98 mm

Sidewall Height: 4.64 in 117.85 mm

Sidewall Height: 4.34 in 110.23 mm

Radius:

14.33 in 363.98 mm

Radius: 14.64 in 371.85 mm

Radius: 14.34 in 364.23 mm

Circumference:

90.03 in 2286.7 mm

Circumference: 92.01 in 2337.0 mm

Circumference: 90.10 in 2288.5 mm

Revs per Mile:

725.7

Revs per Mile: 710.1

Revs per Mile: 725.2

Actual Speed: 60 mph 100 km/h

Speedometer1: 58.7 mph 97.8 km/h

Speedometer1: 59.9 mph 99.9 km/h

Speedometer Difference: - Speedometer Difference: 2.196% too slow Speedometer Difference: 0.068% too slow

Diameter Difference: - Diameter Difference: 2.16% Diameter Difference: 0.07%

You are looking at a bit of difference using the 295 with the same sidewall profile so you can see why they use the 315 as the rolling diameters are almost identical but notice the rim width. Even Tire Rack say's the minimum with 315's are 10" rims which is why a lot of Turbo S owners go with this on the rear. Sorry that was the best I could get the editor fo format it, anyone to do it as HTML.

Edited by hahnmgh63
Posted

The staggered wheel idea is an interesting option. But the sport design wheels I have are 20x9 all the way around so I would like to keep all the tires the same size. i have a feeling the 315 would have that "muffin top" look on the rear 9 inch wide wheels. I wonder what 295/40's all around would do for the handling? hmmmm something to think about. thanks for posting all that info.

It would be nice if anyone can post some pics of their larger/taller tires on oem 20's... any takers ;^)

  • 1 month later...
Posted

Does anyone have the staggered sport techno wheels (9" front 10" rear) and 315/35/20 rear tires on their Cayenne. Just wondering if there are any clearance issues. Photos?

Thanks in advance.

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