Wheel & Tyre Compatibility

[longshanks]

I recently made an impulse purchase - bought some Audi 16" 5 Spoke Alloys to replace my existing 10 Spoke ones.

I think the 5 spokes came from an A8. They are fitted with 225/60 R16 tyres whereas my existing 10 spoke wheels on my A6 are fitted with 205/55 R16 rubber.

I am hoping the wheels and tyres will be compatible but any advice would be gratefully received.

[zollaf]

if you look here http://www.etyres.co.uk/tyre-size-calculator.htm, and put your sizes in, you will find the new tyres are a bigger diameter than your old tyres. this will cause your speedo to be inaccurate, and may also affect performance and economy.

[longshanks]

I can live with the effect on the speedo, performance and economy but am anxious whether the tyres will physically fit within the wheel arches and not be hampered at full lock.

[jwhat]

Could you not swap the tyres from your old wheels to new ones?

[longshanks]

Could you not swap the tyres from your old wheels to new ones?

They must be wider to accommodate the 225s rather than 205s so I guess not.

[Tyre-expert]

You really need to go with a tyre with the same rolling circumference (or diameter) as the original, for several reasons. Speedo inaccuracy is not the only one. Gear ratios and suspensions are set for the vehicle based on this, so the incorrect tyre will affect the handling and torque of your vehicle. The other major problem is that incorrect tyres fitted can invalidate your insurance and would not pass MOT, so you really should go with the original size. The only othe problem is if your replacement wheels are wider than your originals, the 205 55 16 tyres may not fit on the rims, but you could solve this by switching to 225 50 16, which is the same (or near enough within legal tolerance) rolling circumference as your originals. There will be absolutely no issues however with the tyres fitting within the arches. If you had 17" or 18" wheels on, the tyres for these would be the same width (225mm)

[longshanks]

Thank you Tyre-Expert - really helpful stuff.