Spare Tire Strategy

[moparedtn]

You can get a compact scissor jack at Pep Boys for $30. I have ne of those just don’t have the tire.

I'm not the biggest fan of those to be honest, especially on less than ideal/level surfaces.

 

[RobsRR]

I am not sure I understand. Will a mismatched spare ruin a factory posi unit. The wheels spin independently at differerent rates around turns? I just switched to 15 inch wheels because I added 11.75 disc brakes. Bought a 15 inch steel wheel for a spare so it would clear the front brakes but have not put a tire on it.

 

[EngineerDoug]

Wow it looks like I am not the only one who has given this some thought...thanks for your ideas.

I will probably go with 275-60/15 in the rear, and something like a 225-70/15 in the front. That will give me 28" diameter to keep my cruise RPM reasonable, and the front diameter will be 27.4".

This scheme will allow me to use a 215-75/15 spare, which will match the rear tire diameter to within 0.3".

And yes, my understanding is that mismatched rear tires (diameter) will burn up a limited-slip rear. How much mismatch and how far you drive on it is a matter of degree. That's what Cass @ Dr Diff told me.

BTW the way I intend to pack a bottle jack, rather than a scissors or an OEM jack. Scissors jacks scare me; the bottle jack is compact, stable, and affordable.

Thanks again.

 

[Ken Nims]

Carry a can of fix a flat and/or plug kit and small compressor. If you shred a tire your out of luck but this will get you where you need to go. The tire changer will be cuss'n you for the fix a flat. Makes a mess.

I have fixed several punctures on the road with plugs and a portable compressor. Most times I haven't even had to remove the rim for the repair!

 

[oldbee]

Find one that will fit. I'm in the same boat and haven't followed through yet. I might even use a 14" factory wheel with the correct height tire as my rear ones.

I had a vehicle with a limited slip, had a flat on the interstate, changed it with the dognut spare. Never gave it a thought until it was too late, burnt those clutches.

KK, out of curiousity only; how many miles did it take? I’m sure the speed made a difference also.

 

[6PKRTSE]

Man, all this talk about spare tire. I should probably check mine in my Charger. I don't think I have ever even taken mine out of my trunk in the 27-28 years I have owned the car. Good news is all of the factory jack hardware is still there also but I would never trust it & use a floor jack anyway.

 

[khryslerkid]

KK, out of curiousity only; how many miles did it take? I’m sure the speed made a difference also.

It was back in the 80s, we had bought a new AMC and was coming back from visiting relatives in Tenn. Coming up I-81 all of a sudden I noticed something wasn't right. Pulled over and discovered the right rear was almost on the rim.

After changing it to the "space saver" spare, we had about another 50 miles to go to get off of I-81. The spare had a lable on it, said not to go over 50mph so we didn't. After getting off the interstate we had another 50 miles of two lane roads to make it home. Not very much 50mph driving, mostly under that speed going through small towns. So the car was driven 100 miles or a little more.

It wasn't until I fixed the original tire and replaced it that I noticed a noise coming from the rear, especially on a tight turn. That's when it dawned on me that I shouldn't have used that stupid spare. Should have placed it on the front and the front on the rear but I wasn't thinking. Lesson learned.

We had a bad hail storm not long after this and it looked like someone used a ball peen hammer all over the car. Traded it in on another car just to get rid of it.

 

[oldbee]

Whew, 100 Miles of solid turning or so the diff thought.

 

[PeteBell68]

I haven't had a flat in 17 years and on my way home from Carlisle I got two .
So I now carry a spare again 15 inch 225/60/15 that will work on front or back .

 

[RobsRR]

Wow it looks like I am not the only one who has given this some thought...thanks for your ideas.

I will probably go with 275-60/15 in the rear, and something like a 225-70/15 in the front. That will give me 28" diameter to keep my cruise RPM reasonable, and the front diameter will be 27.4".

This scheme will allow me to use a 215-75/15 spare, which will match the rear tire diameter to within 0.3".

And yes, my understanding is that mismatched rear tires (diameter) will burn up a limited-slip rear. How much mismatch and how far you drive on it is a matter of degree. That's what Cass @ Dr Diff told me.

BTW the way I intend to pack a bottle jack, rather than a scissors or an OEM jack. Scissors jacks scare me; the bottle jack is compact, stable, and affordable.

Thanks again.

Why wouldn't you use a 235/70r15 wouldn't that match the rear perfect.

 

[70Del493]

Newby question, but damn have I been looking for a spare.
I have 15" all around (Yes much larger in the rear), it has Disc brakes up front, do I need a "special" rim for the disc brakes vs the drums in the rear?
Rear - 29x12.5R15
Front - 215/70R15
This was a great read, and will have to look at the different size tire issue, but I need a rim first. So where to get one?