Correct tyres for 18" rims on an A3?

[Black_SLine]

Hello,

This is my first post since buying my first audi so sorry if the question is stupid.

Just before xmas I got my A3 sportback 1.8T SLine. I got it with the 18" rims option but found that there was much rubbing of the tyres on the inside of the bodywork.

Of course I took the car back and Audi said they fitted rims with the wrong offset. Fair enough, mistakes happen. So today I collected my car again with the 18" rims with the correct offset but I notice that the tyres do not match what the Audi spec brouchre says. The booklet says that they should be 225/40 tyres for the 18" rims but Audi have fitted 235/40 tyres...

Should I be concerned about this difference?

Ta!!

 

[S3IZZO]

No I wouldn't be concerned...will offer more rim protection

 

[mikep]

235 40 18s could cause rubbing issues as their side profile is 4mm higher than the 225s, and they will screw your speedo up as they are a larger rolling diameter.

Not sure why they would fit the wrong tyres, other than they are Muppets.

 

[Amchlolor]

Aside from being the wrong width, and therefore height, do they have 'XL' or 'EXTRA LOAD' written on the sidewall?
If they don't, that's another reason to get the dealer to change them for the proper ones.

 

[dipstic]

Guess they put on the tyres from the wheels that had the incorrect offset,make them put the correct size on

 

[coupe-se]

235 40 18s could cause rubbing issues as their side profile is 4mm higher than the 225s, and they will screw your speedo up as they are a larger rolling diameter.

Not sure why they would fit the wrong tyres, other than they are Muppets.

Isn't the '40' number referring to the height of the sidewall. Surely a 225 40 will have the same sidewall height as a 235 40 tyre (unless I've been wrong all these years about the 2nd number referring to the sidewall height)?

Anyway, I have 18's fitted and have 225 40 ZR18 Extra Load tyres fitted with no issues at all.

 

[Amchlolor]

Isn't the '40' number referring to the height of the sidewall. Surely a 225 40 will have the same sidewall height as a 235 40 tyre (unless I've been wrong all these years about the 2nd number referring to the sidewall height)?

Anyway, I have 18's fitted and have 225 40 ZR18 Extra Load tyres fitted with no issues at all.

No, the profile is a percentage of the width.
So a 225/40 tyre is 225mm wide, with a 90mm sideall.
A 235/40 tyre is 235mm wide, with a 94mm sidewall.

 

[coupe-se]

No, the profile is a percentage of the width.
So a 225/40 tyre is 225mm wide, with a 90mm sideall.
A 235/40 tyre is 235mm wide, with a 94mm sidewall.

Cheers mate, learnt something today. So the the 40 is actually saying 40% of the width then. :icon_thumright:

 

[Amchlolor]

So the the 40 is actually saying 40% of the width then. :icon_thumright:

:thumbsup:

 

[Black_SLine]

thanks for your advice guys, looks like i'm taking it back to audi - again

ta!

 

[sprout99]

Cheers mate, learnt something today. So the the 40 is actually saying 40% of the width then. :icon_thumright:

yes it's a ratio

the sped rating is generally worthless but the higher the number is the better the tyre performs before it deforms.

i think STD for 18" alloys would be 88 and XL is 92 and above

225/40/18 -92 Y is your ideal tyre

There is a table somewhere that gives you and a max weight for the code.

 

[TDI-line]

Hello and welcome Black Sline to the site.

 

[Xedos]

Audi probably fitted some wheels off an A4 S-Line to your car. They all run 235s or 245s.

I replaced my 225 PZero with 235/40 goodyears. Ride was better / more supple. Done 12k on them now no problems.

 

[Black_SLine]

Took the car for a long drive today with just me and the wife, I didn't notice any problems with the 235/40 tyres audi fitted.

But this evening we went out with two other people in the back the the rears rubbed quite often going around corners.

I want the 18" rims cause they look great, is rubbing with a full load in the car just something I should put up with. I thought it seemed reasonable to think that if audi offer 18" rims as an option they should fit in all conditions.

well, i'll call audi on monday and see what they say...

can anyone tell me if they should be able to fit 225/40s to a rim that is 8 inches wide?