Spare wheel is different size to other 4 wheels????

Calibos

My brother Hyundai Tucson that he bought S/H a couple of years ago from a garage got a puncture on the front passenger side.

I went out to help him change it and the first hassle was the punctured wheel was bonded to the hub. After a bit of googling I learned to put 2 nuts on loosely and drive the car forward and back a couple of times to break the bond.

This worked and we were able to take the punctured wheel off.

We grabbed the spare only to see that A. it was grotty, with bubbled alloy paint inside the rim and most importantly B. a different size to the other 4 wheels on the car!! Now I don't mean it was a space saver that are like a motorbike tire. The allow wheel itself is smaller and the tire diametre doesn't compensate???. ie the 4 wheels on the car are 225/60/R17 whereas the spare is 205/60/R16.

Is this normal? Is this OK to put on to get him a few miles to the nearest tire place? Will one inch of diameter difference make it dangerous to drive or damage the differential or suspension or something like that??

Its too late to sort this evening now anyway. He's insured fully comp in my car as a named driver so will need to borrow my car to take a 30 mile each way trip this evening to collect his fiancee.

So the question is, does he need access to my car again tomorrow to take his punctured wheel down to the tire place in the boot of my car or can he actually fit that 'spare' he has and drive slowly and carefully there in his own Tucson.

Thanks in advance for any advice!

kirving

It's fine to drive, and is better than a space (cost) saver.

One of the following happened:

A) Last owner didn't like the look of the space saver, so bought an R16 wheel cheap.

B) An R17 wheel (on this car or another) was damaged, and the owner (or garage) swapped out the original R17 spare on this car, and replaced it with the R16.

C) Hyundai only give R16's as spares to save money / allow it to fit in the wheel well.

D) The car had R16's originally, and the owner bought 4X R17's.

I'd be getting to car checked to see if it was crashed, because I'd be worried about option B), unless someone confirms otherwise.

colm_mcm

It’s quite possible that it’s correct for the car.

User1998

You can fit the spare wheel. Its completely fine to drive a few miles to the tyre shop.

What I like to do when I get a flat tyre is pump it up with an air compressor to 40 PSI and the tyre will still be inflated when I get to the tyre shop. I haven’t changed a spare wheel in years. I don’t know why more people don’t do this

Sam Russell

The outer diameter of the wheel should be the same whatever the diameter of the alloy - the profile of the tyre is altered to suit. Otherwise the speedo would be wrong. It cannot be legal to drive a car like that. Even a spacesaver wheel cnnot be put on the front, and is restricted to80 km/h.

The spare is from a different car.

Spook_ie

https://www.boards.ie/discussion/comment/119237029#Comment_119237029

Who told you a space saver wheel/tyre can't be used on the front?

route66

There's about a 10% difference in the circumference between the 2 wheels (As per https://www.tyresizecalculator.com):

I'm guessing 10% is too much as it would mess up the ABS sensors and could cause funny handling, maybe even transmission issues ...

Sam Russell

Well, it depends on your car.

Spacesaver tyres are not for prolonged use, nor are they safe for high speed (above 80 km/h) nor for use on Motorways. Really emergency use only.

Limited slip differentials do not like them and could be destroyed. FWD cars might not be able to cope with their differential if the spacesaver is on the front which is why they should go on the back.

They are a tyre for use in an emergency.

Driving on a space saver wheel

If you have a flat tyre and you are using your space saver wheel (also called a temporary use spare tyre or TUST) here are the guidelines:

You must not exceed 80kph (or less if there is a sticker on your space saver indicating the maximum speed is less). This is for dry weather driving; in the wet, go slower.

You must go directly to a place where you can fix your tyre (preferably less than 80km away, but some space savers will say that up to 500km is OK if there is no other option).

If your flat tyre is on the front, and your car is front-wheel drive, swap one of the rear wheels to the front and put the space saver on the rear - this is because the front of the car is used for steering, braking and acceleration and therefore it needs the best rubber at the front.

If you have a rear-wheel drive car with a limited-slip differential, you risk damaging your differential if you put the space saver on the rear. Put it on the front and drive more slowly than the 80kph limit, especially in the rain.

If your car is a standard rear-wheel drive car, the space saver should still go on the rear but be aware that you will wheelspin much more easily.

Never fit more than one space saver to a vehicle.

Driving with a space saver can reduce your cornering grip between 10-15%.

Keeping control under emergency braking and swerving becomes much more difficult.

Quoted from:

https://www.drivingtests.co.nz/roadcode-questions/car/theory/if-you-have-had-a-flat-tyre-and-have-fit/

_Kaiser_

My A7 has one of these space savers and I just know I am going to end up stuck with it sometime on a Sunday when I'm 150km from home and a motorway to get there.

Damn emissions regulations. I would much rather have a full size spare just as I've had in every other car I've owned.

endacl

What if there’s a rip in the sidewall? Or no compressor? Or you’re in the middle of nowhere miles from a tyre shop?

_Kaiser_

https://www.boards.ie/discussion/comment/119247826#Comment_119247826

If that's directed to me I'm not sure what you mean?

If I end up with a flat I call the rescue cover. Far better than trying to loosen airgun welded nuts at the side of a motorway with cars whizzing by at speed.

I'm just saying I'd much rather a full size wheel that I also then don't immediately have to replace two tyres to get back on the road (assuming that the original was unrepairable as per your suggestion).

Strumms

My folks are driving their fourth Tuscon, great car.

Hyundai for whatever reason or this dealership perhaps have a habit now of only providing a runner / space saver wheel recently.

My Dad when striking the deal with them always insisted on a proper alloy as a spare. Once they didn’t come up with the alloy, my dad forgot to look when collecting the car and on getting home it was just a space saver… they begrudgingly asked him over the phone to come in and grab a wheel to which his response was… “ I’m not wasting petrol and my time because you cannot stick to your side of the agreement “ so the sales guy had to drop it on his way home…

spent the guts of 50 grand on the executive plus model too, yet they are nickel and dimeing people on a wheel, bizarre.

zg3409

From the manufacturers point of view while saving a few quid on an actual wheel they can also make boot space larger and create a better co2 rating which may reduce the sales taxes on the car.

I think when I have seen space savers on cars the overall diameter appeared less than the normal tyre. It has been said but you need to drive slowly and carefully when all tyres don't match as risk of losing control is far far higher.

A suggested a good compressor can often get you home depending on the damage to the tyre and DIY repair kits can also help. I also have an extendable tyre spanner for stuck nuts and I test fit the spare as sometimes the spare might not actually fit the car at all, and I try ensure nuts on all wheels are not overtightened.

Popoutman

I do like the folding spares used on some marques. For my car, the OEM tyre size is 275/45R20 and it's just not feasible to carry that size of a wheel and tyre under normal circumstances. So, the manufacturer has the option of using an 18" steel rim with a Vredestein folding spare. Using the supplied 25A compressor, it's fairly trivial to change the tyre to one that has a fair bit more rubber on the road than a spacesaver doughnut tyre. The folding tyre does go to the correct rolling radius for the car, but it is limited to the 80kph rating. This just means that the stability control will work as intended and the air suspension won't have a conniption about the different level of that corner.

It's more than sufficient to get to somewhere safer to either repair or replace the main tyre that deflated. The car was originally supplied without the jack or folding spare, and had the compressor and goop can. I decided that I would be happier with some form of real spare that could get me off a motorway if e.g. a sidewall was cut by something sharp on the road, so I sourced a replacement jack/folding-spare/chocks/wheelguide kit. I'm nuch more at ease with that now.

One caveat with my car is that if it's a front wheel that has deflated, then a wheel from the back must be put on the front and the folding tyre then to be put onto the back - the 18" steel wheel will unfortunately not fit over the brake disk at the front. A bit convoluted but it does make absolute sense.

As for the OP's conundrum, it should be possible to get a tyre to fit on the 16" rim that rolls the same as the 17". A quick check for the possibility would be to see if the 17" wheel and tyre will fit into the diameter of the space for the spare, if so then a 205/70R16 spare should be much closer to the 17" rolling radius.

MakersMark

Just a reminder that's its nothing short of MENTAL to try to change a wheel on the hard shoulder of a main road or motorway.

Do your family a favour and drive to a safe spot, even if it means sacrificing an alloy.

petronius

I hate the space saver tyres - they don't save that much space, I also hate emergency kit to repair a tyre to get you home or a garage and there is no spare! I was tempted to change to an actual wheel/tyre, and actually got one from a scrap yard!

I had a hire car which seemed to have a generic spare? it worked but was visually different from the other wheels, this may be the issue?

Tip - When checking / inflating your tyres - always check pump up the spare!