Compact spare on FWD car drive axle?

[Elkins45]

I was browsing through the owners manual of my 2016 Mazda6 and noticed something interesting about the spare tire. My owners manual says that if I get a flat on my front tire, I need to put the compact spare on a rear wheel and swap the full-size tire to the front. This is the first time I’ve ever seen this advice.

I’m trying to imagine the Chinese fire drill involved in moving a wheel from back to front using only the factory jack. i’m not sure that I would be all that fond of setting my car down on the brake disk while I swap the jack to the front end. Do you guys with FWD cars all carry around jackstands just in case? I think I might just take my chances on driving with the compact spare.

 

[Danh]

Not that hard: 1) remove good rear tire and replace with compact spare; 2) replace flat front with good tire removed from rear. No jack stands needed.

 

[SC Maintenance]

They all say this. I carry a full size spare. I rule out buying any car that doesn't have room for a full size spare. Lots of people think its crazy, but its saved me on long trips more than once.

 

[racer12306]

Not that hard: 1) remove good rear tire and replace with compact spare; 2) replace flat front with good tire removed from rear. No jack stands needed.

Annoying for sure but this ^^^^

Pretty straightforward.


Shoot, I used to do a tire rotation in my driveway one time at a time lol
Big difference was I had a 20V impact to get the car up and down.

 

[benjy]

subarus have had similar notes if ANYONE reads them. common with many AWD vehicles, a pain but better than $$$$$ repairs if you dont + to me a REAL is just smart BUT many full sized spares WON'T fit where the dougnut was!!

 

[twX]

The reason for this is probably because there is less weight on the rear of the vehicle, but I suspect that the load rating of the spare tire would be high enough for any corner of the car (if it's inflated to the specified pressure). The problem with spare tires is that they're usually neglected and underinflated, and probably not equipped with TPMS. Installing a possibly underinflated tire on the rear of a FWD car is certainly less risky and is good practice, which is why 9 out of 10 auto company lawyers recommend it.

I would just install the spare tire on the front if it is properly inflated, unless I was going to keep it on the car for a long time.

 

[Astro14]

What’s so hard about this?

Jack up the rear, replace that tire with the spare. Put it down. Jack up the front, put the rear tire on. Put it down.

Done. Hardest part is finding a safe place by the side of the road.

 

[4WD]

What’s so hard about this?

Jack up the rear, replace that tire with the spare. Put it down. Jack up the front, put the rear tire on. Put it down.

Done. Hardest part is finding a safe place by the side of the road.

I got into deep reading and found that mentioned for the rear having a G80 locker …
That encouraged me to find a full sized spare on that one - and replace big donut spares with real tires on another …

 

[IndyIan]

I was browsing through the owners manual of my 2016 Mazda6 and noticed something interesting about the spare tire. My owners manual says that if I get a flat on my front tire, I need to put the compact spare on a rear wheel and swap the full-size tire to the front. This is the first time I’ve ever seen this advice.

I’m trying to imagine the Chinese fire drill involved in moving a wheel from back to front using only the factory jack. i’m not sure that I would be all that fond of setting my car down on the brake disk while I swap the jack to the front end. Do you guys with FWD cars all carry around jackstands just in case? I think I might just take my chances on driving with the compact spare.

With an open diff car, I would drive a couple miles home on a compact spare on the front, but not too far or too fast... With a low load for a short time, a diff should be fine with mismatched tires. Going 70mph for 10-15 miles may kill one though? I'm not going to run that experiment anyways.

 

[4WD]

With an open diff car, I would drive a couple miles home on a compact spare on the front, but not too far or too fast... With a low load for a short time, a diff should be fine with mismatched tires. Going 70mph for 10-15 miles may kill one though? I'm not going to run that experiment anyways.

I found both a Ford and Chevy sedan that would hold real tires in that sump - reality is with a low aspect ratio - many sedan tires are small …

 

[Astro14]

Years ago, pulling a heavy, likely overloaded, trailer, a twin axle U haul with a piano and furniture loaded in it, with my Volvo 240 wagon, I hit a bit of road debris on the Eastern Shore. The right rear tire blew out with a bang. Kept it under control, pulled over.

Did not want the compact spare on the right rear with the weight of that trailer on the hitch.

Put the compact spare on the right front. Put the right front on the right rear*.

My then six month old daughter slept through the whole thing, so it must not have taken that long to do two changes once the jack was out.


*I stopped at a tire store down the road, put two new Michelins on the back, replacing the one destroyed tire and one other. All set.

 

[IndyIan]

I found both a Ford and Chevy sedan that would hold real tires in that sump - reality is with a low aspect ratio - many sedan tires are small …

Yeah, subaru realized they messed up by not making room for a full size spare in the Outback, and only by like half an inch.... You can fit it if its deflated. The tires are nearly 29" so not small but still... So in 2020 they made room for a full size.

 

[Danh]

Yeah, subaru realized they messed up by not making room for a full size spare in the Outback, and only by like half an inch.... You can fit it if its deflated. The tires are nearly 29" so not small but still... So in 2020 they made room for a full size.

Does Subaru still insist all tires must be within 2/32 inch of tread depth? Would make even a full-size spare a dicey proposition unless it’s part of the rotation pattern.

 

[Soft Cars]

Not that hard: 1) remove good rear tire and replace with compact spare; 2) replace flat front with good tire removed from rear. No jack stands needed.

That's if your onboard jack is able to keep one whole side of the car in the air. Most cars have 4 jack points.

 

[IndyIan]

Does Subaru still insist all tires must be within 2/32 inch of tread depth? Would make even a full-size spare a dicey proposition unless it’s part of the rotation pattern.

The manual says to put the spare on the rear axle, which I would do for sure.
As for the 2/32 thing, its for the long term wear of the centre diff/clutch, and the difference in speeds of the axles. So you can have both rear tires at 7/32, and both fronts at 5/32, and not have excess wear on the clutch. What this also translates to, is the you can have 3 tires the same depth and one tire 4/32 out. So I don't really worry about it. My all-season set is getting down to 4-5/32 so throwing a new tire one wouldn't work long term, but its a super common size so doing some math and getting a used tire that has close enough rotations per miles probably isn't going to be hard to do.

 

[mk378]

That's if your onboard jack is able to keep one whole side of the car in the air. Most cars have 4 jack points.

How in the world is this complicated? Does it need to be spelled out step by step?
1. Loosen the lug nuts on one of the rear wheels.
2. Jack up that corner, swap that wheel (and good tire) for the donut spare.
3. Lower the rear corner and tighten the lug nuts.
4. Loosen the lug nuts on the flat front tire.
5. Jack up the front corner and swap the flat tire with the good full-size one that you removed from the rear.
6. Lower the front corner and tighten the lug nuts.

 

[Eddie]

Or call triple A or a friend in my case. At 85 yo I don't need to risk damage to my body.

 

[eljefino]

It was once bad news for the FWD differential pin to spend a lot of time with one wheel spinning faster than the other. This could encourage the pin to explosively remove itself from the transaxle.

 

[Danh]

That's if your onboard jack is able to keep one whole side of the car in the air. Most cars have 4 jack points.

No need to do that. Two independent jack lifts: one to remove a good rear tire and one one to remove the flat front. The rear tire would be replaced by the spare in the same operation.

 

[Reggaemon]

If I remember correctly Subaru says put the temp on the rear and pull a fuse to disable the AWD.
Yep, just looked my 2009 owners manual and that what it states. Don't know if that's the same for newer models.