Wrong wheels? Tyre load rating?

[samwise1]

Hi all,

I wondered if anybody has the technical knowledge to be able to advise me on whether the non-standard wheels that have been put on my car are okay? I am am not technically/mechanically gifted so hope that somebody out there is!

I have a 2005 VW Passat 2.0 TDi 140 SE Saloon and the last owner has put some 17" 9-spoke Audi RS alloys on it, shod with 225/45 R17 94 tyres. They look good but from what I can find online this car should have either 215/55R16 97W, 235/45R17 94W or 235/40R18 95Y tyres depending on the wheel size, for standard VW wheel options but based on the B6 1.9 TDi version, not the 2.0 TDi. I would like to check if the wheels/tyres that have been fitted are safe for my car and how they would affect the handling/ride that the car would have with the correct fitment?

Lastly, does anybody know if VW centre-caps are available that can be swapped easily with the Audi ones? The car looks a little odd with Audi badges!

Cheers!

[A4Ade]

I'm no expert either, but from reading around on this over the last few years here is my 2p:

1. The 225/45 R17 tyres will have a slightly smaller sidewall than the stock 235/45 R17, this may slightly effect the ride but I'm sure I have read about loads of people doing this and I doubt it would make much difference.

2. For the same reason, the rolling radius will be slightly shorter, meaning your speedo will be slightly out. But this way round it will be out the "acceptable" way (it will over-read), and only by ~1 mph anyway. So, e.g. if the speedo says 60 mph, you will actually be going ~59 mph (but actually, probably even slower as speedos tend to over-read anyway).

3. The main reason (I can see) that people put on narrower tyres (apart from error!) is for stretch. This could be for appearance reasons, or to stop rubbing if the suspension has been lowered. You haven't said how wide the wheels are so it's hard to say much here, but *if* the new wheels are the same width as the stock, then the tyres will be stretched slightly away from the edge of the rim. This might leave the rims themselves a bit more exposed to curbing, but that also probably depends on the brand and what sort of rim protection they have.

I found an article about the effects of stretch which might make for worthwhile reading - I'm not sure about the rules of posting links, but googling for "tyre stretch handling" ought to do it...

[neilos100]

I think the main issue here is whether your insurance company will pay out in the event of an accident if you are using non-standard or recommended tyre sizes and load ratings....not saying that will definitely happen but you know what insurance companies are like!
Neil

Sent from my phone...

[A4Ade]

According to the OP, both the stock and the ones he has fitted have a load rating of 94 for R17 wheels, so that should be ok (although the speed rating isn't given for the fitted tyres). But you're absolutely right, anything non-standard *ought* to be approved by your insurance company... I had non-standard wheels on my previous car and my insurance company were fine, but definitely best to let them know.


I think the main issue here is whether your insurance company will pay out in the event of an accident if you are using non-standard or recommended tyre sizes and load ratings....not saying that will definitely happen but you know what insurance companies are like!
Neil

Sent from my phone...