Hi guys

on my superb I have as summer tires 225/45/r17 which I think are not very comfortable for driving - I can feel all road bumps and I already had a damaged tire due to a pot hole in 6 months since I have the car.  This never happened to me before always having tires with bigger " balloon". It's a big difference now with the winter tires 205/55/r16 compared to the summer ones.

 

So since I did not find anybody wiling to buy my wheels or to exchange with some smaller ones with bigger balloon, I want to put this kind of tires: 225/55/r17

I did some calculations:

for current 225/45/r17, tire diameter is 53.3cm

for what I want:225/55/r17, tire diameter is 55.5cm

According to papers I can fit the 225/40/r18 with a tire diameter of 54.72

So I would be 2.2 cm bigger than current size and 0.8cm bigger than the max allowed according to the papers

 

What do you think?

Will there be any issues with the ESP/ABS? Speed reading I guess will not work fine, either way it does not in most of the cars

Any chance during bumps the tires will hit the car wings?

Fuel consumption will increase, I guess  

 

Thanks!

 

 

 

So you want a better ride - stay on 17 or go 16 - or go for 18??

 

Try this calculator:

https://www.wheel-size.com/calc/?wheel1=225-45-17X7.5ET45&wheel2=205-50-17X9ET45&fcl=50mm&scl=50mm&wcl=30mm&sr=0mm

 

Already set to stock 225/45/17 and 205/50/17 - only 0.4% difference

http://kouki.co.uk/utilities/visual-tyre-size-calculator 

Thanks guys, seems my formula had an error!

I am thinking to go with 205.55R17 to get a better sidewall height(11.275cm) similar to the winter tires I have now 205.55.r16

the wheel height increases from 63.43cm to 65.73cm but i think it will be ok 

Edited 22 February, 20179 yr by Racataian

The instrument cluster can be recoded for larger tyre size using VCDS. One of the options for the Superb equates to the stock range of sizes (205/55/R16, 225/45/R17, 225/40/R18) while the other is equivalent to 235/45/R18.

 

Your proposed 205/55/R17 has a smaller circumference than 235/45/R18 by 4 cm. It is larger than 225/40/R18 by 6 cm. So recoding to the larger option will minimise the error. One other thing to consider though is that coded to the larger size your speedometer will underread i.e. the speed it shows will be smaller than what you are actually travelling at.

 

As a side note, that calculator on kouki.co.uk is calculating the nominal tyre dimensions. It does not take account the reduction in rolling radius due to tyre deflection under the vehicle's weight. It also won't account for variation in tyre tread construction. Use it (and any tyre size calculator) with caution.

There are already several topics regarding exactly this topic on this forum. Use the search function, or Google (first hit). The suggested 225/55R17 will however never fit, but 225/50R17 does.

A number of people on here have improved the comfort in their cars by changing to a tyre with a profile 5 higher than the standard tyre size so change from a 225/45/R17 to 225/50/R17. This sizing is used on quite a lot of Audis and the Superb has the clearance to take these tyres.

 

Tyres in this size seem to cost significantly more however, so swapping to a wheel size smaller could be cheaper long term (Especially if you sell the alloys you have). I run 17" wheels with standard size tyres for the summer and 16" wheels on standard size tyres for the winter and can't fault the comfort on either of them though I get a little more nervous on really rough surfaces if I'm running the 17s, while I get more nervous on really greasy surfaces on the 16s as the 17s have noticeably more grip. The steering is slightly lighter while parking with the narrower 16" tyres though.

 

I've been in a Superb running 18" wheels also and the comfort on that seems fine to me too though it is slightly harsher (or sportier depending on how you like your cars to feel) than 17" wheels.