Spare wheel

[Beaconjon]

Hi all, bit of an odd one this but here goes.

We're on holiday in France and were planning on doing about 1250 miles in our 2nd week in our 09 MK5. We had a small vibration on the front wheels so I popped into a local garage to get it checked only for them to discover a huge ding/crack on the inside of the front right alloy. It's clearly hit something recently.

Anyhow, we have the 17 inch rims that came with the car and can't source a new one for a few days (£300!!!!!) tyres are 215/40zR17 87w

For some reason I thought the spare was full size but its a steel rim but it ain't. It's a 185/60R15 84T.

It's marked up with a 50mph max speed.

I know it's a miss match but surely this wheel is capable of more than that?

As it is we've cancelled our long driving and are now staying in northern France until the new rim arrives.

Any advice re speed on this wheel would be interesting.

Cheers Jon

 

[NetworkMan]

I'm as puzzled as you. My 1.2 TSI SE has 185/60-15 as standard but he spare is, IIRC, 175/70-14. Neither your spare or my spare are true spacesaver tyres; they are what I'd call undersized normal tyres. In fact it's not even as bad as that since in both cases the tyres are standard fit on a lower spec Ibiza.

I can only think they rate the spare at 50 mph just because you will be running with one tyre smaller than the other three.

Wish I could be more help.

 

[BaldyDave]

Call me cautious, but if it's marked as 50MPH max I'd stick to that. It's just intended for temporary use as you know.

Sorry, know this is not the answer you are looking for!

 

[Beaconjon]

Probably best to take the advice and not really use it.

I think I'd be tempted to get a set of more standard wheels as the low profiles are stupidly expensive and terrible in bad weather.

 

[J400uk]

I reckon you could safely exceed 50mph. Its not a space-saver spare as its a proper sized wheel and tyre, the rolling circumference will be about the same as your lo-profile 17s.

 

[Biker]

I found myself in the same position as you a while back, 300 miles from home a burst tyre and as it was late at night no place to get it fixed.
I swapped the tyres round on the car so I had a matched pair on the front and the spare on the rear. I drove the 300 miles home at motorway speeds and didn't notice any difference in the handling of the car. I have no doubt the tyre/wheel are capable of much higher speeds than 50mph and the warning is because of the width difference. Fitting the spare to the rear minimises the effects of that.

Having said that, not sure what would have happened if I had been stopped by plod doing 70mph on a wheel marked up with a max speed of 50mph or what the insurance company would have made of it had I had an accident!

 

[G.P]

As it is we've cancelled our long driving and are now staying in northern France until the new rim arrives.

Heath & Saftey!!! Be thankful you can still get around as you have a spare

I think I'd be tempted to get a set of more standard wheels as the low profiles are stupidly expensive and terrible in bad weather.

Could by lots of replacement tyre's for the cost of 4/5 new wheels. How is a low profile tyre terrible in bad weather?

 

[BaldyDave]

Nothing to do with how low profile a tyre is when confronted with bad weather, it's to do with the type of tyre you have fitted to the rims...

If it's winter weather you are talking about, you get some winter tyres fitted.

 

[dashnine]

I was also wondering why a 185/60R15 was fitted as a 'space saver' so looked into it. The boot space with the wheel in it together with all the spacing / padding underneath to clear the battery is ludicrous! Usually a 'space saver' looks like something from a 2CV!

A wheel / tyre size calculator out there somewhere in Google land came up with the answer: 185/60R15 is about the nearest you can get to the 17" wheel / tyre combination rolling radius, less than 1% difference I think from memory.

So the 50mph sticker is on there because the RR is not exactly the same and I guess it may upset the ABS / ESP system in an 'incident'. But I think the main reason for the sticker is that if you prang the car and try to claim it's due to the tyre mismatch SEAT have absolved themselves from any blame.

 

[Beaconjon]

Heath & Saftey!!! Be thankful you can still get around as you have a spare



Could by lots of replacement tyre's for the cost of 4/5 new wheels. How is a low profile tyre terrible in bad weather?

They aquaplane in in the wet and are terrible in the snow. Nice and grippy in the dry though obviously.

 

[DEAN0]

They aquaplane in in the wet and are terrible in the snow. Nice and grippy in the dry though obviously.

That has nothing to do with profile - that is about tyre width.

It is all about weight over surface area and the tyre treads ability to clear water.

A 215 wide tyre on a small car will aquaplane the same if it is 30 profile or 70 profile.

 

[BaldyDave]

Yep you are confusing low profile tyres with wide tyres... Deano has a point IMO. It's all about the tyre contact area and the amount of weight that the car applies on it... The wider a tyre is, the more difficult it is to shift water from under it which ultimitely can cause aquaplaning if the tread is not properly designed.

As for snow, you ideally need a tread designed for snow so that it grips properly, and also a lot of weight pushing the tyre tread into the snow... It's why some people fit narrower wheels/tyres in wintry conditions (though I'd be careful about doing this).