Tyres

Stick with 185/65/15 on the spare.

You'll find that the steel rim is probably half an inch narrower than the alloy rims, hence the difference in tyre size.

However, the circumference of a 195/60/15 and 185/65/15 will be almost exactly the same.

Cheers

(and apologies about the double post - Thunderbird still hasn't figured out that if there are no references, it's not a follow up!)

Cya Simon

ITYF that is actually the common situation...

The 185/65/15 will be 6mm larger in diameter.

Perfectly acceptable as a spare, but I personally would not use it in the long term.

Is the spare actually illegal? If so, I would either look around for a s/h alloy to replace it, or else fit the cheapest tyre I could reasonably find on it.

Chris

Just out of interest, where did you get 6mm from? The Tyre Rolling Circumference calculator at says it will only be 2mm (static) or 3mm (dynamic) different.

Spare alloys can be a pain - I had them for my Supra and they took up almost all of the boot. They were 225/50x16 though.. and the boot was pathetic.

VW are completely illogical - they put a steel spare in cars with alloys, but the steel spare is exactly the same size as the alloy tyre. Doesn't make any sense at all, to me.

Also a PITA when dealing with the lease company - as they can ask Thick Fit to swap a decent tyre off the spare onto an alloy to save money.

Sem do have spacesavers though.

If you stump up the extra for an Audi, you get an alloy spare.

Makes things a lot easier.

The oddest thing I've seen is my Fabia vRS with a steel spare, in the same size, with the same tyre, but with a warning sticker like a space-saver has.

Circumference?

I used this site:

Amusingly, the early Fiesta XR2i's had a spare wheel well that wouldn't take the spare wheel! They were supplied with the wheel floating around loose in the boot.

Later, the boot floor pressing was modified with a "power bulge".

Chris

'All the way round the outside' ;-)

Circumference difference between those two was about 20mm different.

My mistake anyway, I was using radius but didn't specify it, that table shows diameter, so we're not so far apart.

The shaped boot floor carpet in the Supra had a bulge for the tyre too. Above the bulge to the rear screen was all of about 6".

Amazing really, for a car of near identical power and weight to the Carlton GSi, it was a "2+uncomfortable 2 with no boot space" compared to "a good 5 seater with room to rent out the boot to 14 illegal immigrants"...

Saving of a couple of quid I guess. Merc do the same thing; even though it also means you need to carry an extra set of wheel bolts as the alloy ones are too long to fit steel rims with - I found out the hard way when I split a tyre! Luckily it was in my drive.

It makes perfect sense, they're just tight.

Try this:

Thanks, but the information in the link I provided is accurate, and very close to the one above.

Chris