Space saver spare not the same diameter as a standard road wheel.

Submitted: Friday, Sep 24, 2021 at 22:46
ThreadID: 142623 Views:1266 Replies:9 FollowUps:40
Looking for some advice from the knowledge base here.

I have recently bought a battery electric car for our urban use but we'll do the occasional highway road trip in it.

It came without a spare tyre, just a toy compressor and a bottle of goop. Not being a fan of the goop and what it does to an internal TPMS sensor if used in anger (and the subsequent cost of remediation), I sourced a space saver spare.

Because the vehicle comes without a spare, there is no factory option. With a bit of research I found one from a different car manufacturer. PCD and stud pattern is fine, centre hole is fine, offset appears ok - according to texta marks on the garage floor, centreline of the tyre when mounted closely matches the centreline of a factory original.

Only thing not quite right is overall diameter. Diameter is about half an inch larger than OEM road tyre, so radius about 1/4 inch larger.

The vehicle is front wheel drive.

I suspect there will be no issue if the spare is put on the back.

But is that 0.5 inch difference in diameter significant if on a driving wheel at the front? I'm aware of handling considerations but I'm mainly thinking about the differential. I suppose there will also be other considerations such as ABS, traction control, stability control, all that stuff.

In common with other space-savers, the wheel is placarded at 80kph max with which I will, of course, comply. And only use it for the minimum distance to get home or to a tyre shop, etc, etc.

And yes, in the event of a flat on the front I could put the spare on a back wheel and move the rear wheel to the front, but I would really appreciate some comment about the mechanical considerations of a slightly larger diameter (0.5 inch) on one of the driving wheels.

It's an open diff.

Is that half inch difference between sides, about 2%, significant?

Thanks all in advance.

FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

Back Reply Expand Un-Read 0 Moderator

Reply By: Michael H9 - Saturday, Sep 25, 2021 at 06:16

Saturday, Sep 25, 2021 at 06:16
Over the years, I've on occasion accidentally driven with one of the tyres under inflated by a few pounds without any issues. An under inflated tyre would easily equate to having a diameter 1/4 inch difference between the wheels.
AnswerID: 638047

Follow Up By: Member - McLaren3030 - Saturday, Sep 25, 2021 at 08:45

Saturday, Sep 25, 2021 at 08:45
Hi Michael,

How did you work that out, or am I missing something? Surely the circumference of the under inflated tyre hasn’t changed, so the speed at which the circumference of the tyre is turning also hasn’t changed. Changing the diameter of the wheel/tyre will make a difference to the speed at which it rotates owing to the change in circumference. That is the circumference is larger so it will rotate faster. An under inflated tyre hasn’t changed the circumference of the tyre.

Macca.
Macca.

Lifetime Member
My Profile  My Position  Send Message

1
FollowupID: 916255

Follow Up By: RMD - Saturday, Sep 25, 2021 at 09:01

Saturday, Sep 25, 2021 at 09:01
Macca
You said, "the diameter is larger and will rotate faster"????? Don't you mean slower. Yes, the circumference of a flat tyre is the same but the effective radius is less and tyre squirm and heat production alters it a bit. An Audi vehicle can detect 4psi difference in tyre pressure and subsequent rotation rate difference.
0
FollowupID: 916258

Follow Up By: Member - McLaren3030 - Saturday, Sep 25, 2021 at 09:12

Saturday, Sep 25, 2021 at 09:12
Hi RMD,

No, I meant what I said. If you increase the diameter of a wheel, the circumference is larger, therefore if the axle is rotating at the same speed, then the circumference has to be going faster. Think of the tip of a wind turbine blade, it is turning at a much higher speed than the axle of the turbine.

Macca.
Macca.

Lifetime Member
My Profile  My Position  Send Message

0
FollowupID: 916263

Follow Up By: AlbyNSW - Saturday, Sep 25, 2021 at 09:16

Saturday, Sep 25, 2021 at 09:16
Tyre inflation differences does not alter the diameter or rotation speed of a tyre, all it does is alter its shape.

As far as having a different diameter spare goes, I would run it on the rear of a FWD vehicle unless you know how the drivetrain on that particular vehicle works.
Could be a costly repair otherwise
1
FollowupID: 916265

Follow Up By: Michael H9 - Saturday, Sep 25, 2021 at 13:56

Saturday, Sep 25, 2021 at 13:56
No, the diameter changes and the wheel rotates faster if it goes flatter. The circumference doesn't change but the tyre deforms . A lot of cars use this as a basic tyre pressure monitoring device by using the wheel speed sensors.
0
FollowupID: 916288

Follow Up By: Allan B (Sunshine Coast) - Saturday, Sep 25, 2021 at 14:03

Saturday, Sep 25, 2021 at 14:03
.
Hi Alby,
I always have trouble getting my head around the physics of tyre circumference/radius. It is possible to consider that 1 revolution produces travel of 2r x Pi. (where 'r' equals the measured distance from wheel centre to the road. But 1 revolution also lays down on the road the actual manufactured circumference of the tyre which may well be greater than the previous. The two circumferences are not the same. I can only imagine that some tyre slip comes into it?

But to your premise above that tyre inflation "does not alter the diameter or rotation speed of a tyre".
The OEM tyre pressure monitors being fitted to many new cars is not a true pressure reading sensor but is derived from the wheel rotation sensors originally charged with input to traction control systems. They deduce that any wheel turning faster than the others must be of smaller effective diameter and therefore running at a lower pressure. It may not be sufficiently accurate to read out a numerical pressure value but is adequate to raise an alarm. So these systems demonstrate that a lower-pressured tyre rotates faster.
Cheers
Allan

Member
My Profile  My Blog  My Position  Send Message

0
FollowupID: 916289

Follow Up By: Michael H9 - Saturday, Sep 25, 2021 at 15:44

Saturday, Sep 25, 2021 at 15:44
Check out Aristotle's wheel paradox, but put your theoretical physicist cap on first... :-)

0
FollowupID: 916295

Reply By: Allan B (Sunshine Coast) - Saturday, Sep 25, 2021 at 07:15

Saturday, Sep 25, 2021 at 07:15
.
Hi Frank,

Two thoughts..... I guess that your concern is the 'exercising' of the diff due to diameter mis-match. Consider how much 'exercising' a diff experiences when travelling on a winding track. I would think that this would be a similar amount and if speed were limited then no harm would come to the diff.

But then also think outside the box. If you need to put the spare on the front axle, simply deflate the opposite side tyre a little to match the radius of the spare. Again, at reduced speed the deflated tyre will come to no harm.
Cheers
Allan

Member
My Profile  My Blog  My Position  Send Message

AnswerID: 638050

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 09:52

Saturday, Sep 25, 2021 at 09:52
Thanks Allan, that is exactly my concern.

Using exactly the logic you have used, I suspected that the minor difference would be ok on a short term basis, but could only "suspect". I am really looking for confirmation (or otherwise if I am wrong), so thanks for your advice.

Unfortunately it is the spare that is the larger. The placards say it has to be run at 60PSI so it would be even more of a safety compromise to deflate it to better match the other side.

I suppose I could over inflate the other side a bit in an effort to increase its rolling radius, but EV tyres are already designed to "stay round" at the bottom (please forgive the licence here) with little give in the sidewalls (minimum rolling resistance for max economy) so I doubt there'd be much benefit.

Ahh, the joys of being an early adopter!
FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

1
FollowupID: 916270

Follow Up By: AlbyNSW - Saturday, Sep 25, 2021 at 10:33

Saturday, Sep 25, 2021 at 10:33
Alan deflating the tyre does not alter its radius, the length of tread has not altered you have just changed the shape
0
FollowupID: 916273

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 10:50

Saturday, Sep 25, 2021 at 10:50
I'm afraid I agree with Allan.

Alby, you are correct in that the circumference doesn't change. When the tyre is deflated, more of the circumference rests on the road to accommodate the reduced rolling radius.

The rolling radius of the tyre is reduced when it is deflated. That is, the distance between the road surface and the centre of the wheel IS reduced. This will cause that wheel to spin faster at a given speed than a fully inflated wheel of the same nominal size.

FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916275

Follow Up By: Zippo - Saturday, Sep 25, 2021 at 11:23

Saturday, Sep 25, 2021 at 11:23
Frank, you accept that the circumference doesn't change with inflation. So why do you think the distance travellelled per revolution will be different? They are the same thing.

The concept of rolling radius is a nonsense in this discussion. The height of the axle above ground is immaterial.

Back to the original post subject, almost every manufacturer who supplies space-savers as OEM will direct that they should ONLY be used on a non-driving axle. (*) For FWD that implies that if a front tyre fails, you replace it with one from the rear axle and fit the space-saver at the rear. That is spelled out in some vehicle owners' manuals.

I refuse to buy vehicles that only come with a space-saver. Ironically, some have the space for a full size wheel/tyre and fit a packer to the top of the space-saver to support the floor piece. So they are only weight/cost savers.

(*) If you have a Volt/Bolt i.e. "electric 4WD" you would have a dilemma with a space-saver.
1
FollowupID: 916278

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 12:40

Saturday, Sep 25, 2021 at 12:40
Thanks Zippo. I'll think more about the "rolling radius" concept. Your (and others') argument about unchanged circumference is persuasive but as you say, it has little to do with the main issue so I'll leave it aside for the moment and try to get my head around it later.

My vehicle did not come with a spare at all so there is no guidance in the manual about how to properly use the space saver I have bought. Also its diameter is slightly larger (2%) than a road wheel. Hence my questions here.
FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916285

Reply By: Batt's - Saturday, Sep 25, 2021 at 07:17

Saturday, Sep 25, 2021 at 07:17
I would have thought an electric car doesn't have a diff just an electric motor behind each front wheel so the car would want to be turning in a large circle as the motors want to run at the same speed. So the spare would have to go on the rear.
AnswerID: 638051

Follow Up By: Michael H9 - Saturday, Sep 25, 2021 at 08:18

Saturday, Sep 25, 2021 at 08:18
If that were the case the car would struggle to turn any corners. They invented diffs for a reason so there must be a similar system in place for cars with electric motors in the wheel. Perhaps one side motor is disabled by wheel speed sensors?
0
FollowupID: 916251

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 08:26

Saturday, Sep 25, 2021 at 08:26
No, Batt's. Most have a single motor, front or rear, driving through a single, permanently engaged reduction gear to a diff and then the wheels. Some performance models have two motors for AWD.

There is an American start-up company, Rivian, that has created a F150-sized ute with a motor on each wheel. There are a couple of prototypes on the road for testing. From all reports they easily outperform equivalent conventional vehicles.
FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916252

Follow Up By: RMD - Saturday, Sep 25, 2021 at 09:05

Saturday, Sep 25, 2021 at 09:05
Batts.
Only one electric motor. If wheel motors were used the weight of unspring items would vastly increase, not done usually unless in slower vehicles.
0
FollowupID: 916260

Follow Up By: nick g1 - Saturday, Sep 25, 2021 at 10:44

Saturday, Sep 25, 2021 at 10:44
Yes Frank, l have been following the Rivians. Look like a great design and very capable. Love the tank turn that they can do. But at approx $100,000 Aussie dollars way out of my price bracket!
0
FollowupID: 916274

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 10:54

Saturday, Sep 25, 2021 at 10:54
Nick,

You and me both!

As a second best you could try for the electric F150 which, though it's a bit more conventional in its drive train, also gets incredible write-ups.

I suspect the affordability index is not too dissimilar :-(
FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916276

Follow Up By: RMD - Saturday, Sep 25, 2021 at 12:00

Saturday, Sep 25, 2021 at 12:00
Michael H9
If wheel motors are used, the electronic control is actually 4 different speed and power controls and instantly allows for ANY speed differential of wheels, it also senses any slip of ANY wheel and reduces the power but not the speed so you never know the multitude of power/speed and energy sharing being done at any one instant in time. If you turn the steering it knows what is has to cater for!
1
FollowupID: 916282

Reply By: rumpig - Saturday, Sep 25, 2021 at 08:22

Saturday, Sep 25, 2021 at 08:22
Couldn’t you just put the spare on the back first, then use the back tyre you take off to replace the front flat one? Yes it means changing 2 tyres, but atleast you know it’ll be the same size
AnswerID: 638055

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 08:28

Saturday, Sep 25, 2021 at 08:28
Thanks Rumpig. I mentioned that in my opening post. I'm thinking more for Mrs P who is unlikely to want to change two wheels to fix one, LOL.
FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916253

Follow Up By: Michael H9 - Saturday, Sep 25, 2021 at 08:32

Saturday, Sep 25, 2021 at 08:32
That's good that Mrs P changes the tyres for you. My wife just sits in the car. :-)
4
FollowupID: 916254

Follow Up By: Member - McLaren3030 - Saturday, Sep 25, 2021 at 08:54

Saturday, Sep 25, 2021 at 08:54
Do you have roadside assistance? When Mrs. P is driving, she could ask the nice roadside assist people to help.

Macca.
Macca.

Lifetime Member
My Profile  My Position  Send Message

0
FollowupID: 916257

Follow Up By: RMD - Saturday, Sep 25, 2021 at 09:06

Saturday, Sep 25, 2021 at 09:06
A flat tyre? that is a Tilt Tray experience isn't it?
0
FollowupID: 916261

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 09:12

Saturday, Sep 25, 2021 at 09:12
"Do you have roadside assistance? When Mrs. P is driving, she could ask the nice roadside assist people to help."

Yes, Macca, we do. Comes free of charge with the car. But we'd rather be on our way than twiddling thumbs waiting for someone to turn up and do what we can do.
FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

1
FollowupID: 916262

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 09:24

Saturday, Sep 25, 2021 at 09:24
"A flat tyre? that is a Tilt Tray experience isn't it?"

LOL, RMD.

We are reserving the tilt tray experience for the remote possibility that we totally mismanage the traction battery and run out of juice. That then becomes a tilt tray ride to the nearest charger. Unfortunately you cannot bring a 5 litre container of electrons to an electric vehicle to get it moving again.

Though, speculating here, when EVs are the norm roadside assist might include a quick mini charge with a mobile super capacitor to get you on the move again. Or something like that.



FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916266

Follow Up By: ian.g - Saturday, Sep 25, 2021 at 11:19

Saturday, Sep 25, 2021 at 11:19
Have owned two cars that had space saver spares, both required that the space saver was only run on the rear of the vehicle (Front Wheel Drive) In both cases the rim physically wouldn't fit over the front discs and caliper. Still don't know how vehicle manufactures get away with it. One was a Ford the other a Nissan.
0
FollowupID: 916277

Follow Up By: RMD - Saturday, Sep 25, 2021 at 11:53

Saturday, Sep 25, 2021 at 11:53
ian.g
They never tried it, that is why. Buying one is a problem solvers course development centre, We give the space saver and you work out how to solve your problem. We are not there so it isn't our problem! They get away with it because NO ONE ever checks it all prior to rego certification. Similar, was the washing machine water pump for engine cooling added on a remote bracket to 4cyl Magna vehicles years ago. Story was the engine design never included a cooling flow pump and "catch up" was the name of the game and some Mitsubishi engineers suddenly had sore bums.. Only happened on one design.
1
FollowupID: 916281

Reply By: RMD - Saturday, Sep 25, 2021 at 09:19

Saturday, Sep 25, 2021 at 09:19
Frank
Depending on the ESC electronics sensitivity it has, it may or may not detect the speed difference and I agree changing tyre pressure slightly would get you out of trouble for the short time it is used. As the differential is only rotating at a very small "differential rate" the side and spider gears should be able to handle that easily and in a vehicle life time they get to actually rotate a lot, not fats at any time. Heck, if the side and spider gears can withstand HIGH rotation, when Joseph Coolness does wheelies in his Commodore, until he runs them dry, your Normal travel with a slight rotation happening isn't going to be a problem.

PS, Although the stated space saver rating may be 80kmh it effectively has not much grip or cornering ability and far less speed at any time is a great idea. They effectively use the opposite side tyre grip to stop side slip. and braking ability is unkown especially in an emergency.
AnswerID: 638058

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 09:30

Saturday, Sep 25, 2021 at 09:30
"PS, Although the stated space saver rating may be 80kmh it effectively has not much grip or cornering ability and far less speed at any time is a great idea. They effectively use the opposite side tyre grip to stop side slip. and braking ability is unkown especially in an emergency."

They are a pretty shonky answer to the problem, aren't they. An accountant's approach to an engineering problem, eclipsed only by the next step which was to leave them out altogether!

FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916268

Follow Up By: Briste - Saturday, Sep 25, 2021 at 09:34

Saturday, Sep 25, 2021 at 09:34
There is a shonkier accountant's answer to this problem - run flat tyres. Uggghhhh!
2
FollowupID: 916269

Follow Up By: RMD - Saturday, Sep 25, 2021 at 11:45

Saturday, Sep 25, 2021 at 11:45
Briste
The 'AAA" class Mercedes has Run Flats, ie, Electric MB and others, many do and different widths front to back too and no spare., "cos the rears won't fit the front. That is leading edge technology apparently. MB are the bestest aren't they.
1
FollowupID: 916280

Follow Up By: RMD - Saturday, Sep 25, 2021 at 12:05

Saturday, Sep 25, 2021 at 12:05
Frank
You have me worried. Were the TEXTA marks used, a wide felt line marker or a fine liner, just thinking of your normal applied degree of accuracy.
1
FollowupID: 916283

Follow Up By: Briste - Saturday, Sep 25, 2021 at 12:23

Saturday, Sep 25, 2021 at 12:23
RMD - I am only too painfully aware of that. There's an MB B-Class (non-electric or hybrid) in the garage with low profile RFT. It's our around-town car. At one stage both cars had RFT. Never again!

The advantage of the RFT has been that it reduces the risk of the usual driver (who does NOT change tyres, unlike Mrs P) getting stranded by a flat, although it doesn't elimate it entirely. I'm pushing to replace it with a Hyundai Ionic hybrid with comes with a radical, innovative feature: A FULL SIZE SPARE, glory be! (Note, the PHEV and electic Ionic do not). No luck so far ....
0
FollowupID: 916284

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 13:20

Saturday, Sep 25, 2021 at 13:20
"Frank
You have me worried. Were the TEXTA marks used, a wide felt line marker or a fine liner, just thinking of your normal applied degree of accuracy."

LOL, RMD.

After raising and lowering the car to change the wheel, any accuracy engendered by the use of setsquare and fine draughtsman's pencil (NOT!!) was lost when the geometry of the IRS cause the lowered wheel to rest in a slightly different place. If I had used a fatter jumbo marker or a 1"paintbrush the results would have been perfect.

I fear Zippo may have torn an accuracy stripe off my epaulettes in the radius/circumference aside :-(
FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916286

Follow Up By: RMD - Saturday, Sep 25, 2021 at 14:53

Saturday, Sep 25, 2021 at 14:53
Frank
Yes, the suspension does move around a fair bit. People who drive hard must never know how much the suspension and wheel AND tyre alters it's position. Most have never seen the action of a suspension and especially the tyre pulling under the rim when cornering to the MAX.
The position where the tyre sat and tread actually returns to because of sideways grip when lowering can be 10mm easily. A "texta mark on tread centre and ground and then raise and lower it to when it begins to grip will show the difference. Tyre gets pulled inward, rim forces outward axially.
I would prefer to fit it to the front and know what is feels like and does so no surprises if needed to be used. The scrub radius and steering centre to tread centre may be upset a little.
0
FollowupID: 916293

Reply By: qldcamper - Saturday, Sep 25, 2021 at 14:39

Saturday, Sep 25, 2021 at 14:39
Are they even legal here yet.
I know when they first started showing up in AU they didnt comply, especially if being used on a vehicly they were not designed for.
AnswerID: 638065

Reply By: Frank P (NSW) - Saturday, Sep 25, 2021 at 16:53

Saturday, Sep 25, 2021 at 16:53
Thank you everyone.

I think the main point coming out of this discussion is that the space saver should not be used on the front due to handling and braking issues.

My initial concern was the effect on the front wheel drive differential should I need to put the spare on the front. That is clearly of secondary importance. If necessary the spare will go on the back and a good back wheel will go on the front.

FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

AnswerID: 638066

Follow Up By: Zippo - Saturday, Sep 25, 2021 at 18:26

Saturday, Sep 25, 2021 at 18:26
That "s/s on the back and the back wheel to the front" is the best you can do with them. But the obvious question is: As the vehicle came without a spare, if you can accommodate a space-saver why can't you deal with a full-size spare (you know, a REAL one)?
0
FollowupID: 916297

Follow Up By: Frank P (NSW) - Saturday, Sep 25, 2021 at 18:46

Saturday, Sep 25, 2021 at 18:46
My car is a Hyundai Kona EV.

The boot space cannot accommodate a full sized spare under the floor, but it can accommodate a space saver. A full sized spare above the floor is simply impractical for safety and space reasons.

Hyundai could have done a space saver but they chose not to.

FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916301

Follow Up By: RMD - Saturday, Sep 25, 2021 at 19:35

Saturday, Sep 25, 2021 at 19:35
Frank. Can you buy a full size wheel, but a dehydrated one and just add water when it is needed? That should fit!
1
FollowupID: 916303

Follow Up By: Gronk - Sunday, Sep 26, 2021 at 10:04

Sunday, Sep 26, 2021 at 10:04
Chances are you won’t ever get a flat. BUT, if it’s on the front, with an open diff, you won’t have any mechanical issuers.
As for handling and braking issues, you are limited to 80 k/ph, and unless you intend to attack corners or aggressively brake, there won’t be any issue there either.
2
FollowupID: 916313

Reply By: Hoyks - Monday, Sep 27, 2021 at 08:51

Monday, Sep 27, 2021 at 08:51
Put it on the front and drive slowly.
The logistics of jacking it up so both wheels are off the ground to do the rear to front and add a spare are asking for trouble, especially using the factory jack on a playing field that isn't of your choosing.

The tyre radius wouldn't pose any more issues than driving around a constant curve in the road and you're only nursing it until the next town or where you can get the wheel fixed, rather than thousands of km hard driving.

The contact patch of the space saver will significantly decrease the available traction in that corner, so the traction control will have to work harder as that wheel will be more likely to lose traction, so too the ABS. But its easy enough to drive smoother and slower so both systems are not needed in the 1st place.

I don't like space savers and have replaced them with a proper skinny steel rim and tyre in the past, but if you don't have any where to stow it, a crappy space saver is better than nothing.

Sticky string tyre plugs are probably a better option than the tube of goop if it is a simple nail through the tread.
AnswerID: 638089

Follow Up By: Frank P (NSW) - Monday, Sep 27, 2021 at 09:36

Monday, Sep 27, 2021 at 09:36
Thanks Hoyks. I think I'll make up my mind on the day if I'm there.

If I were to do a front to rear swap I wouldn't use two jacks. I would first jack the rear and replace a good wheel with the spare and then jack the front to replace the flat with the good wheel. I doubt Mrs P would do that. She will call me or road service to assist.

I've already decided to get a sticky string kit for simple tread area punctures.



FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916346

Reply By: Michael ( Moss Vale NSW) - Tuesday, Sep 28, 2021 at 09:14

Tuesday, Sep 28, 2021 at 09:14
Gday Frank,
I think you may be overthinking the whole concern. Why bother with the spare at all? You could buy a decent plug kit and leave it in the boot, you probably have roadside service, the roadside guy could use that to plug a tyre. That would save your wife changing the tyre, i'd prefer my wife didn't do that. Its not usual to have a flat tyre on the road these days, its usual to find it in the morning as it slowly deflates overnight or over a few days. You mentioned it has TPMS, that would alarm while driving if deflating and save the tyre and also it would alarm in the morning at start up if the pressure is low, so you would avoid any permanent damage to a tyre. I guess also you are retired, how often would you be not in the car when your wife is driving and how far away in that car would your wife be without you. My wife's Corolla we bought in 2010 has 190,000k's on it, the original spare wheel has never seen the light of day, its never had a puncture. Just my thoughts, maybe some of my points have been mentioned above, i didn't read them all, the replies are quite comprehensive. regards Michael
Patrol 4.2TDi 2003

Retired 2016 and now Out and About!

Somewhere you want to explore ? There is no time like the present.

Member
My Profile  My Blog  My Position  Send Message

AnswerID: 638110

Follow Up By: Frank P (NSW) - Tuesday, Sep 28, 2021 at 10:54

Tuesday, Sep 28, 2021 at 10:54
Hi Michael. Thanks for the reply. I'm not sure about overthinking the need for a spare - we do intend to use the car for motel style regional touring and interstate family visits via routes less direct than the main highways. You're right - punctures these days are infrequent but I would be uncomfortable doing what we plan to do without a spare of some sort. And I will carry a plug kit - would prefer to travel on a repaired road wheel anyway.

Surprisingly, we don't lose any storage space by carrying the SS wheel. It and the jack kit fit under the boot floor and simply replace the goop kit and other stuff that was in a hard foam anti-rattle insert.

I probably did overthink the issues surrounding the slightly different wheel diameter, but I'm glad I asked about it here because the input I have received in that regard has set my mind at rest. And we were able to sort out the deflated wheel speed issue! LOL.

Just waiting for the gates to open.

Cheers

FrankP

Lifetime Member
My Profile  My Blog  My Position  Send Message
Moderator

0
FollowupID: 916378

Follow Up By: Michael ( Moss Vale NSW) - Tuesday, Sep 28, 2021 at 14:51

Tuesday, Sep 28, 2021 at 14:51
All good Frank, I was thinking it was just a run around Black top vehicle, i did think about the space you will use up but that's not a problem.. Enjoy your new vehicle. regards Michael
Patrol 4.2TDi 2003

Retired 2016 and now Out and About!

Somewhere you want to explore ? There is no time like the present.

Member
My Profile  My Blog  My Position  Send Message

0
FollowupID: 916385

Sponsored Links

Popular Products (13)