vRS Spare Woes

[powerd]

Let's clarify some of the terminology:

Remember folks, if your spare (whether it be full-sized or a space-saver) is unmatched, the vehicle is technically not roadworthy. Therefore, unmatched factory spare tyres should only be used as intended - i.e. temporary use only.

OP should by now have more than enough information to make an informed decision.

Thanks Diesel - however, it doesn't quite answer my my question. I know the sizes of both my spare and the main wheel as wheel as the tiny difference in rolling diameter. What I am trying to find out is what is the actual legal reference or, if possible, the exact text, which defines the requirmeent. The rta info above does not appear to be a regulation or whatever, just guidance? I am guessing the legislative instrument is state-based but hopefully it is consistent across states.

I have even asked at dealers and people just look dumb and then recite personal opinions, most of which are inconsistent. It seems to me that the 80km/h on the full size spare may not legislatively prescribed but a manufacturer's specification. Even driven very hard, the performance reduction of the spare on the rear was so small as to be negligible. And that is in the context of a car with high pefrromance tyres on the other three wheels.

Anyone have the specific reference or content?

[MarksVRS]

Quick question; Does anyone know if the Dunlops are directional? MV Skoda didn't rotate my tyres at the 15,000 service which leads me to believe that they might be.

Yes, the Dunlops are directional although that should not stop them being rotated front to back. The fronts will always wear faster as they do all the accelerating and braking so the rotation should always be part of each service to get the maximum life.

On the other hand, with the bubble in the wall of my tyre I will not risk fitting it to the front, as this will compromise steering and braking if it were to blow. I prefer to let the tyres wear faster on the front.

[MarksVRS]

It seems to me that the 80km/h on the full size spare may not legislatively prescribed but a manufacturer's specification. Even driven very hard, the performance reduction of the spare on the rear was so small as to be negligible. And that is in the context of a car with high pefrromance tyres on the other three wheels.

Anyone have the specific reference or content?

Seriously, why worry?? It does not take a brain surgeon to understand that tyres of a different brand, width, tread let alone size will influence how it reacts in an emergency situation so just accept it!!!
An insurance company could very easily argue:
** The space saver prevented maximum braking to be acheived, which is why you rammed the car in front of you at the stop sign, or
** The car aqua-planed across to the wrong side of the road due to differing treads/widths creating a lateral force which is why you had the head-on or
** The space-saver prevented maximum traction when trying to round the hair-pin in the wet, which caused you to strike the pedestrian/tree/car etc etc on the far side of the bend.

Need I say more?

Do not give police or insurance companies any chance to place blame on you, even if it seems unreasonable in your eyes.

[gldgti]

Seriously, why worry?? It does not take a brain surgeon to understand that tyres of a different brand, width, tread let alone size will influence how it reacts in an emergency situation so just accept it!!!
An insurance company could very easily argue:
** The space saver prevented maximum braking to be acheived, which is why you rammed the car in front of you at the stop sign, or
** The car aqua-planed across to the wrong side of the road due to differing treads/widths creating a lateral force which is why you had the head-on or
** The space-saver prevented maximum traction when trying to round the hair-pin in the wet, which caused you to strike the pedestrian/tree/car etc etc on the far side of the bend.

Need I say more?

Do not give police or insurance companies any chance to place blame on you, even if it seems unreasonable in your eyes.

But its not a space saver

Mysticality, Re: rotating - all tyres should only ever be rotated front to back. Never one side of the car to the other. Tyres end up with some hysteresis due to the direction of rotation coupled with the normal loading, and when you reverse it, the molecules all have to realign again which causes the tyre sidewall undue stress. Not saying that your tyres will explode if you do, just saying its less than ideal

Further, all tyres, whether directional, assymmetrical, both or neither, can be rotated from front to back.

[powerd]

Need I say more?

.

That's the point. I am only interested in the legal requirement not peoples opinions or biases. because i have tested it at the upper end of the vehicle's limits and could find no significant reduction in stability, grip, balance,ABS or ESP response or other safety related performance. The only thing I could not test was wet weather performance, but I would expect it to be good, and the ABS/ESP compensate for whatever tyres are on the car - as confirmed by an engineer from a carmaker (who basically said, the registration authorities have little undersatnding of modern car systems). All I got was a different feel dynamically, but nothing that could be considered a safety risk. It is, after all, a quality full size tyre, on a standard steel rim of 16" diameter. It is not a spacesaver.

Does anyone know th elegal requirement or where to find it?

[K1W1]

Further, all tyres, whether directional, assymmetrical, both or neither, can be rotated from front to back.

Except of course on cars where the rear tyres are a different size to the front tyres.

[dArK5HaD0w]

But its not a space saver

+1
there is a MASSIVE difference between a space-saver spare & a full-size spare!!!
one is a bicycle wheel. the other is a standard wheel commonly found on non-sporty cars
the full-size spare tyre in the vrs is the same normal/std wheel size found on all 4 corners on the 118TSI & 103TDI models.
it is a more than capable tyre.

[Diesel_vert]

Does anyone know the legal requirement or where to find it?

This is for Queensland:

TRANSPORT OPERATIONS (ROAD USE MANAGEMENT - VEHICLE STANDARDS AND SAFETY) REGULATION 2010

(2) A motor vehicle that is a car, car derivative or off-road passenger vehicle using car tyres must not be fitted with

(b) any wheel in which

(ii) the diameter, width or offset of its rim differs from the rim of another wheel on the same axle

And for South Australia:

ROAD TRAFFIC (MISCELLANEOUS) REGULATIONS 1999

(3) Every road wheel fitted to an axle of a motor vehicle or trailer must

(c) be of the same rim width and have the same offset of the rim relative to the mounting face

Victoria is a little different. The legislation doesn't specifically state tyre and wheel size requirements on a given axle. Instead they refer to the Vehicle Standards Bulletins (specifically, VSB No. 14 for cars) which supplement the legislation requirements:

ROAD SAFETY (VEHICLES) REGULATIONS 2009

(3) A person who modifies, or adds components to, a vehicle must ensure that

(a) if the vehicle complied with the standards for registration immediately before the modification or addition, the vehicle continues to comply with those standards; and

(c) for a light vehicle

(i) the modification or addition is certified by an authorised person as complying with the National Code of Practice for Light Vehicle Construction and Modification published by the Department of Infrastructure, Transport, Regional Development and Local Government as Vehicle Standards Bulletin No. 14; or

(ii) the modification or alteration is otherwise acceptable to the Corporation.

The "Corporation" refers to VicRoads.

So while the Vehicle Standards Bulletins aren't binding per se (by itself), the above legislation effectively makes them binding. Tyre and wheel size requirements are covered in NCOP11.


Likewise, NSW has a similar provision, even if it isn't as clear:

ROAD TRANSPORT (VEHICLE REGISTRATION) REGULATION 2007

(3) A person who modifies, or adds components to, a registrable vehicle must ensure that

(a) if the vehicle complied with the applicable vehicle standards for the vehicle immediately before the modification or addition - the vehicle continues to comply with those standards, and

(b) the modification or addition is certified by an authorised person as complying with the National Code of Practice for Heavy Vehicle Modifications (1993) published by the Federal Office of Road Safety as Vehicle Standards Bulletin No 6 or a specification published by the Authority or is otherwise acceptable to the Authority (emphasis added).

The "Authority" refers to the RTA.

Again, even though the Vehicle Standards Information sheets (tyres and wheels are covered in VSI No. 9) aren't binding per se, the above legislation makes them binding. I would also expect VSB No. 14 to carry similar authoritative weight with the RTA.


As for the other states and territories, it would be better to assume their legislation would be similar (I haven't checked).

I have tested it at the upper end of the vehicle's limits and could find no significant reduction in stability, grip, balance,ABS or ESP response or other safety related performance. The only thing I could not test was wet weather performance, but I would expect it to be good, and the ABS/ESP compensate for whatever tyres are on the car - as confirmed by an engineer from a carmaker (who basically said, the registration authorities have little undersatnding of modern car systems). All I got was a different feel dynamically, but nothing that could be considered a safety risk. It is, after all, a quality full size tyre, on a standard steel rim of 16" diameter. It is not a spacesaver.

There is scope in the NSW legislation for persuading the authorities, but I don't think they would consider your argument strong enough.

[brad]

Thanks Diesel - however, it doesn't quite answer my my question. I know the sizes of both my spare and the main wheel as wheel as the tiny difference in rolling diameter. What I am trying to find out is what is the actual legal reference or, if possible, the exact text, which defines the requirmeent. The rta info above does not appear to be a regulation or whatever, just guidance? I am guessing the legislative instrument is state-based but hopefully it is consistent across states.

I have even asked at dealers and people just look dumb and then recite personal opinions, most of which are inconsistent. It seems to me that the 80km/h on the full size spare may not legislatively prescribed but a manufacturer's specification. Even driven very hard, the performance reduction of the spare on the rear was so small as to be negligible. And that is in the context of a car with high pefrromance tyres on the other three wheels.

Anyone have the specific reference or content?

Check the ADR?

Otherwise you need to check with your State Gov't department (RMA in NSW) or you could ask your regional motoring association technical or legal department (if you are a member).

80kmh would be the maximum the tyre mfrs have agreed on for space-savers. If you've ever driven on a proper spacesaver then you will know that 80kmh is about as fast as you'd like to go (it was on my Cabrio). i would assume that rather than introduce a higher limit (and confuse the General Public) for full size spares they stuck with 80kmh.

[brad]

On the other hand, with the bubble in the wall of my tyre I will not risk fitting it to the front, as this will compromise steering and braking if it were to blow. I prefer to let the tyres wear faster on the front.

If I had the choice of which end I'd prefer a tyre to blow, I'll pick the front thanks.

I used to think rear was better but a mate who used to be in the NSW HWp & has been an Advanced driving instructor & Demonstration driver (V8 Experience, etc) has changed my thinking.

[woofy]

So bascially no spare is legal in Australia unless its identical. Great work by the ADR for making sure this kind of crap doesn't happen.

[brad]

Mysticality, Re: rotating - all tyres should only ever be rotated front to back. Never one side of the car to the other. Tyres end up with some hysteresis due to the direction of rotation coupled with the normal loading, and when you reverse it, the molecules all have to realign again which causes the tyre sidewall undue stress. Not saying that your tyres will explode if you do, just saying its less than ideal

Further, all tyres, whether directional, assymmetrical, both or neither, can be rotated from front to back.

Hysterisis is fine providing you put the tyres that changed direction on the lazy axle. It allows them to "relax" back to a normal state rather than being "wrenched" back on the drive wheel.

[Diesel_vert]

Check the ADR?

So bascially no spare is legal in Australia unless its identical. Great work by the ADR for making sure this kind of crap doesn't happen.

Actually, the requirement has been legislated by the state governments. So far as I can tell, there is nothing in the ADR which requires the tyres and wheels to be of the same size for a given axle.

I should expect the situation to be the same in most jurisdictions worldwide.

It is one of the reasons why unmatched spares (whether they be full-size or space-savers) should be for temporary use only.

[Transporter]

I wouldn't even question that, because it's kind of hard to believe that the space saver would make your car illegal and your insurance invalid in the case of accident.

The bottom line is that, there are the speed limit and the max. distance that you can travel on it, and be fitted to the rear axle only.

[Diesel_vert]

I wouldn't even question that, because it's kind of hard to believe that the space saver would make your car illegal and your insurance invalid in the case of accident.

That's why the manufacturer says to limit your speed to 80 km/h, repair or replace the damaged tyre ASAP, and drive cautiously until then. Not that any of these recommendations are binding in any way, but it would be in the driver's best interests to follow them in full.

As I said before, if one's vehicle were to be involved in an accident, IMO it is probable that a reasonable insurance assessor will not reject a claim based on use of the vehicle's standard unmatched spare tyre - provided you were following the manufacturer's recommendations as best you could.

However, as the vehicle is technically not roadworthy, the option to reject the claim remains open nonetheless.

But don't fret if the supplied spare in your vehicle is unmatched - as long as one uses it as intended, one shouldn't get into any more trouble than is necessary.