Hi, I've just purchased a 2023 Karoq Sportline, I want to buy a 19" space saver spare. is it ok to use a space saver on a 4wd? or are there caveats?

or if there is not enough room in the boot for a 19" I'll buy an 18" spare space saver, it's the 4wd that Im not sure about.

thanks

 

12 hours ago, Rusby said:

Hi, I've just purchased a 2023 Karoq Sportline, I want to buy a 19" space saver spare. is it ok to use a space saver on a 4wd? or are there caveats?

or if there is not enough room in the boot for a 19" I'll buy an 18" spare space saver, it's the 4wd that Im not sure about.

thanks

 

The only space saver for the Karoq listed in the Skoda parts catalogue is 3.5Jx18 ET25.5, ie. no 19" space saver is shown.

 

The below 18" space saver is sold for the Octavia MK3, Octavia MK4, Superb MK3, Karoq. However, all these cars except for the Octavia MK3 use tyres that have an outside diameter bigger than a 125/70R18 tyre. For the Karoq 4WD I would use a 135/80R18 rather than a 125/70R18, as that closely matches the outside diameter of the standard tyre sizes on the Karoq 4WD.

 

Outside diameter of tyres

125/70R18 632.2mm

135/80R18 673.2mm

225/60R16 676.4mm

225/55R17 679.3mm

225/50R18 682.2mm

225/45R19 685.1mm

 

135/80R18 space saver tyre

https://www.camskill.co.uk/m129b0s7672p0/Temporary_Spare_Tyres_-_Space_Saver_Tyres_-_18_inch_R18_inch_-_135_80_18_135_80R18_R18_inch_-_135_18_135R18

 

As you can see in the ETRTO chart below, 135/80R18 fits a 3.5J rim.

 

ETRTO approved rim widths

135/80R18 3.5-3.5-4.5

 

125/70R18 fitted to 3.5Jx18 ET25.5 5/112 57.1 steel space saver rim

https://eshop.skoda-auto.cz/cs_CZ/kompletni-rezervni-kolo-18/p/5E3601011B

 

Edited 22 April, 20233 yr by Carlston

Thank you for the prompt response, however my real question is .....is it ok to use a space saver wheel on any of the 4 wheels of a 4wd  karoq...I see lots of responses about 2 wheel drive vehicles where people say if its the driven wheel, (front) on a 2wheel drive car that has the puncture, replace it with one of the back wheels and put the space saver on the non driven wheel..ie the rear, well if its a 4wd, the Sporttline for example...and they are ALL driven...what is the advice then??

7 hours ago, Rusby said:

Thank you for the prompt response, however my real question is .....is it ok to use a space saver wheel on any of the 4 wheels of a 4wd  karoq...I see lots of responses about 2 wheel drive vehicles where people say if its the driven wheel, (front) on a 2wheel drive car that has the puncture, replace it with one of the back wheels and put the space saver on the non driven wheel..ie the rear, well if its a 4wd, the Sporttline for example...and they are ALL driven...what is the advice then??

In an ideal world the temporary wheel would be just to get you a few miles to a tyre depot at low speed so wouldn't really matter which wheel it is on.   
 

In poor weather tends to be easier to handle the car if it is on the back (not that you should be driving enthusiastically with a space saver).

 

In recent years, Skoda UK has fitted many cars with obscure tyre sizes, rather than common sizes, so inevitably a replacement has to be ordered as not stocked, so instead of being used for a hour, people spend days driving around with space saver on which is less than ideal.   So then ideally need to switch space saver to back if needing to use car whilst waiting for a tyre to come from a warehouse somewhere.

 

 

Thanks for your post, I was concerned that putting a space saver on a 4wd driven axle might cause damage & yes I fully understand that you have to be much more cautious in driving with a space saver on.

I don't know the answer about damage but @toot probably will and with my call out to him will post here as he's a very helpful chap.

 

In the meantime - 

8 hours ago, Rusby said:

I see lots of responses about 2 wheel drive vehicles where people say if its the driven wheel, (front) on a 2wheel drive car that has the puncture, replace it with one of the back wheels and put the space saver on the non driven wheel..ie the rear

It also depends on if the car is RWD and has a limited-slip diff. 

 

Personally I'd avoid using a space saver on any vehicle and have done for over 20 years since fitting a space-saver (at front) to a low powered MX-5 (RWD no LSD) and travelling at only 30 mph through town.  I personally would certainly avoid it on a 4X4.

 

Because of fashion all modern vehicles (over here at least) have very oversized wheels and tyres so when wheel of 3.5" wide and tyres 125 (5" nominal) and 135 (5.3") is seen they're totally unfamiliar with them.  I still have a spare (full-sized!) 3.5" wheel in my shed with a 145 (5.7" nominal) tyre and most people would now be amazed that such wheels and tyres were on vehicles in the past.

 

Assuming your tyres are 225/45 R19 (stupid Skoda site has "19" Vega alloy wheels in polished black" and "Tires 205/40 R17 84W"(!?) if you had a 135/80 r18 you would be going from (nominal) width of 225 (8.9") to 135 (5.3"), 125 (5") would be even narrower of course.- 

 

 

Edited 23 April, 20233 yr by nta16
more detail

Even though temporary and going only to a safe place or for repair at a reduced speed there can be issues with Haldex  & systems if not near enough the correct circumference.

No CC / ACC that is OK, but if the brakes are nipping, over heating that is an issue, but that should not happen. 

Some says it did.

The thread is somewhere from last year on one owners car having issues with the spare on i think a Superb and how the wrong size spares came with the new cars and the discussion do you put it on the front or the rear and do the car jack up and wheel change shuffle.

Edited 23 April, 20233 yr by toot

2 minutes ago, toot said:

there can be issues with Haldex  & systems if not near enough the correct circumference.

In the above example from Carlston's recommended 135/80/18 (80 profile, them were the days) there's only a (nominal) 1.9% difference would this be acceptable mechanically and for the computer not to light up the dash like a Xmas tree?

 

And would the 135 against 235 make any odds on normal roads?

 

Sorry I'm not sure you got a conclusive answer, perhaps more posters will add later.

 

53 minutes ago, nta16 said:

And would the 135 against 235 make any odds on normal roads?

Assuming the circumference is the same, that's a contact patch that is 43% smaller - so in wet or slippery conditions (mud, ice, snow, etc.) I would say that would be a noticeable difference in grip across the axle.

Indeed,

And 50 mph is the Max speed you should travel at with one on, but common sense might well have you slower in those conditions.

 

As you should do with any spare even with the same width of tyre but maybe Green / Unused, with possibly a different pressure, compound, tread & wheel if a steel / weight. 

Edited 23 April, 20233 yr by toot

3 hours ago, PetrolDave said:

Assuming the circumference is the same, that's a contact patch that is 43% smaller - so in wet or slippery conditions (mud, ice, snow, etc.) I would say that would be a noticeable difference in grip across the axle.

Yes that's the point I was getting at.

 

toot might know but I can't remember the details now (longer patch on thinner tyre?) but the (driven?) tyre contact footprint isn't a straight percentage equation one width against another which is why going up one tyre width or so didn't mean more "grip as there's more tyre on the road" because it was about the same but it all got lost in the mine's bigger than yours fashions.

 

But as you and toot have put having three X-make and model of 225/45/19 tyres with whatever wear and pressure against one Y-make and model of 135/80/18 possibly unused tyre at the same(?) or different(?) pressure isn't the best match of the four corners.

 

3 hours ago, nta16 said:

Yes that's the point I was getting at.

 

toot might know but I can't remember the details now (longer patch on thinner tyre?) but the (driven?) tyre contact footprint isn't a straight percentage equation one width against another which is why going up one tyre width or so didn't mean more "grip as there's more tyre on the road" because it was about the same but it all got lost in the mine's bigger than yours fashions.

 

But as you and toot have put having three X-make and model of 225/45/19 tyres with whatever wear and pressure against one Y-make and model of 135/80/18 possibly unused tyre at the same(?) or different(?) pressure isn't the best match of the four corners.

 

The length of the contact patch depends on the circumference of the tyre, so if the circumference is substantially the same (in this case a diference of 1.9% is stated)  then the length of the contact patch will be substantially the same and hence the contact patch area will be almost completely determined by the tyre width - hence why I only took tyre width into account in my earlier calculation.

17 hours ago, PetrolDave said:

The length of the contact patch depends on the circumference of the tyre, so if the circumference is substantially the same (in this case a diference of 1.9% is stated)  then the length of the contact patch will be substantially the same and hence the contact patch area will be almost completely determined by the tyre width - hence why I only took tyre width into account in my earlier calculation.

 

Apologises I got mixed up.

 

Edited 24 April, 20233 yr by nta16

I've not read everything in detail, this is just my take on things.

Are you going to use the car as a 4WD, in other words, going off road?

If you are then it's a no brainer to me,  you need a full size spare.

I'll leave it there for the moment, and see what replies come in.

Briskoda needs a thread on anyone Green laning or offroading a Karoq and what all terrain or offroad tyres they fit.

Likely not 18 or 19" ones.