17" rims with 45 aspect tyres.

KIBOURED

Member
Hi all, I have an A2 Tdi with standard Audi 17" 9 spoke rim which I think are 7J. I need to replace the tyres but I have a good set of Mitchelin's which can off of another car of ours which I would like to use. Normally these wheels use 205/40/17 but the one's I have are 225/45/17. Do you know if they will fit OK?? Thanks for any comments. Rich
 
Thanks for that advise and thanks Dave for the link to tyre/wheel options. I am thinking based upon the comments so far that this tyre option isn't going to work. I have a local tyre place who could fit these onto the rims just to see. If I do just 2 to start I can rotate from front to back in pairs to see how it feels. If satisfactory I could get the remaining pair done. You mentioned the rolling diameter knocking the speedo out, will this increase or lower the reading? On the current tyres when travelling at 50 on the speedo, the satnav is saying 47. I am tying to understand if the extra tyre wheel size will make this better or worse? I suppose if I do decide to mount the tyres my finding might be useful to others. Cheers Rich
 
OK, based upon that latest information I shall not fit these tyres. 6% may be OK for me but to someone else driving it might tip the balance on speed camera's etc. Appreciate you taking the time to reply. Rich
 
OK, based upon that latest information I shall not fit these tyres. 6% may be OK for me but to someone else driving it might tip the balance on speed camera's etc. Appreciate you taking the time to reply. Rich

Hi,

The dial on the speed seems to be always set to over read slightly with a higher speed then the car is actually doing. The car does know the correct speed and if you have DIS you can reset the average speed and get a number readout of the correct current speed.

When I changed from 40 profile tires on the 17" wheels to 45 profile, when measured using a sat nav, the larger wheel diameter seemed to exactly compensate for the built in over read on the dial and correct it so that the dial and sat nav speed where the same. The car will however think that you are traveling slightly slower than reality and so the millage will be slightly less than the distance traveled. As long as you remember that the dial is now the correct speed you should be OK.

regards

Andrew
 
Hi,

If I could add my input perhaps.

Andrew is correct about the speedo readings, but I think he may have been using 215 45 tyres not 225 45 tyres and so that affects the width a fair bit.

The speedo difference between your true speed and the Speedo reading will be very close. currently with OEM tyres on your speedo will read something like 53 MPH at a genuine 50 MPH. With tyres of the diameter you are considering you will be doing 53 MPH rather than 50, so your speedo will be more accurate.

BUT, the tyre width of 225 WILL give you problems, it will rub on the wheel arch and/or inner wheel tub (depending on the ET of your wheels)

I managed to squeeze 215s on my A2 and they did JUST rub occasionally and I had to grind away some of the inner arch plastic to get more clearance and they also rubbed slightly on the inner wheel tub, so 225 is not going to work unfortunately.

Steve B
 
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