Full size spare necessary?

[Tethmes]

It goes in the corner in your garage. After 5 tire rotations you will have a full set to fall back on in the future.

That's good advice after I decide what my long term tire is going to be (I do plan on keeping the jeep for 200k+ miles). Living where I do I'll have to see how I like these KM2's in the snow next winter, but I have a feeling I won't prefer them over other options I've run in the past and will probably end up defaulting to the trusty KO2 long term.

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[BadAssBumbleBee]

That's good advice after I decide what my long term tire is going to be (I do plan on keeping the jeep for 200k+ miles). Living where I do I'll have to see how I like these KM2's in the snow next winter, but I have a feeling I won't prefer them over other options I've run in the past and will probably end up defaulting to the trusty KO2 long term.

I ran a 285/70/17 KM2 on my 2012 JK Rubicon for a few winters and wasn't overly impressed with them. They did handle deep snow pretty well, but they were a real handful when the roads were covered in just a light dusting of snow.

I ended up siping the center tread blocks and that did help improve traction, but in the end I just went back to using the stock 255/75/17 BFG KM's during the winter and then switched back to the KM2's in the spring/summer.

 

[2nd 392]

They never rotate at the same speed when not straight and level.



That's what differentials are for. I'm not saying lock the differential when you have a different size tire. Put the small tire on the front and drive home in 2 WD. Then you have no problem.



Ridiculous. Even when locked that's not true. The tire with the least traction will slip. Even worst case with lockers, which I'm saying don't use, small tire on rock, large on loose dirt, which will slip?



You're obsessed with lockers. That's what differentials are for.

I know guys who commute daily and extremely winding roads. 50,000 miles and their differentials are fine.

You're going panic mode for putting a smaller tire on the front and driving home. If the OP doesn't want a full size spare, don't get one. He'll be fine driving home to anyone who understands how a differential works. I've seen it in action. Finish the run, drove home 45 miles. No detectable change in the front differential fluid.

I must assume you've never done any serious wheeling with lockers engaged. Rock crawling with front and rear locked put far more strain on the driveline than no front locker with different size tires.

Where were you when I was asserting never drive in 4H with the transfer case locked on the highway when you hit dry spots. Another guy said I was foolish to think some highway driving in 4 Hi (not full time 4 WD option) would be problematic on dry corners.

Precisely— my PU’s tires are too big for the spare spot so if I get a rear flat the spare goes on the front (no front LSD) front tire to back, 2WD, get repair ASAP. No problem, other than extra work.

 

[Tethmes]

I ran a 285/70/17 KM2 on my 2012 JK Rubicon for a few winters and wasn't overly impressed with them. They did handle deep snow pretty well, but they were a real handful when the roads were covered in just a light dusting of snow.

I ended up siping the center tread blocks and that did help improve traction, but in the end I just went back to using the stock 255/75/17 BFG KM's during the winter and then switched back to the KM2's in the spring/summer.

Well it looks like I'll get to test it out sooner than I thought. It appears we're getting a freak snow storm late in the year and are expecting up to 6 inches tomorrow. Kind of glad it's happening now as it'll give me all summer to reconsider my tire choices before winter hits again!

 

[CaJLMetalHead]

Have been contemplating if getting the full-size spare is worth it.

Here's my first question:
If you don't get the full size spare, do you get a donut wheel and tire, or an inflator kit?

Honestly, I've never in all my life needed to use a spare tire yet (knock on wood).
But if I do, I'm not one of those morons who would put on a temporary spare and then drive around on it for days, weeks, or even months.
I'd put it on and go get a new tire immediately if I could, or within a day or so. But if I couldn't get a spare tire put on that same day, I wouldn't drive the car until I located or ordered a replacement OEM size tire.

So is it really necessary to carry around a $500 option in your trunk, or save the weight and money and just have a spare size tire or an inflator kit in the car?

Also with the full size spare option, do you get another regular OEM polished wheel or just a steel 19 inch wheel?
If it's another actual wheel that may be worth it just to have a spare wheel in case you damage one of your wheels.

Thoughts?

I would go with a full-size wheel tire that matches the rest of the rig...

a) You can rotate all 5 wheels and get more miles compared to 4 (it also makes it
easier since you have an extra wheel to rotate around instead of having to jack up the
entire rig if you do it yourself)

b) if you off-road and one tire gets slashed... then using a little donut spare is going
to be painful / dangerous

c) not having a properly sized spare tire is frowned upon among off-roading
groups... as it means potentially having to let you use one of their spare tires
in case you damage a tire beyond repair on the trail (and what if everybody in
the group is running 8 lugs wheels and you have 5 lug wheels?)

d) at some off-roading events the organizers won't let you join rides if
you do not have a properly sized / working order spare tire

You could always save money by buying a cheap wheel and getting someone to
donate an old tire that matches the size of your tires ..

 

[BDinTX]

We cut a sidewall in Colorado on a factory size KO2. It took two days to track one down and a 60 mile drive to get it. Too many downsides to not having a full size spare that you can rotate in just to try to save a few bucks.

And even if the answer is yes I think it falls into the category of "Just because you can, it doesn't mean you should"

 

[J0E]

Correct me if I am wrong, but upping the tire size means I should add reinforcement to the tailgate, relocate the brake light, and of course, pay for another tire.

Right, that's an additional cost.

. I understand if I have a flat, it'll be an awkward drive to get the tire fixed/replaced, but is that the only issue to be aware of? I don't wheel heavily, and don't expect to. I appreciate the help! Please help me understand if there is something i am missing.

You won't even notice it.

Difference is that those tiny donuts are the exact same diameter as the full size tires.

Not true

Your spare tire, be it a full-size non-matching spare tire or a compact spare, is typically a smaller diameter than your four normal use tires. It may be a slight half-inch up to a couple inches in diameter different and the width is usually significantly less than your factory tires.

Too many downsides to not having a full size spare that you can rotate in just to try to save a few bucks.

What downsides? The inconvenience of putting it on the front? It's not a few buck. Tailgate reinforcement + new 37 is not a few bucks.

We cut a sidewall in Colorado on a factory size KO2. It took two days to track one down and a 60 mile drive to get it. Too many downsides to not having a full size spare that you can rotate in just to try to save a few bucks.

And even if the answer is yes I think it falls into the category of "Just because you can, it doesn't mean you should"

If you're that risk averse, carry two spares.

 

[rickinAZ]

Right, that's an additional cost.



You won't even notice it.



Not true

Your spare tire, be it a full-size non-matching spare tire or a compact spare, is typically a smaller diameter than your four normal use tires. It may be a slight half-inch up to a couple inches in diameter different and the width is usually significantly less than your factory tires.



What downsides? The inconvenience of putting it on the front? It's not a few buck. Tailgate reinforcement + new 37 is not a few bucks.



If you're that risk averse, carry two spares.

Just curious what you are picturing: four badass 37s and a whimpy donut on the tailgate? Seems like an odd place for an owner to economize.

 

[dsgrey]

I have a non-Jeep hybrid that doesn't have a spare. Comes with an inflator with fix-a-flat and that bothers me.

The only 2 times I've required a spare in 40+ years or driving:
1) couple of years ago on a non-tpms vehicle, tire went flat and shredded by the time I stopped.
2) 30 years ago, ran over a banding strap which sliced a back tire.

Both instances above without a spare I'd be calling someone to pick me up, abandon the car on the side of the road, try to find a shop to buy a tire, return and install. If it's 2am on a Sunday then I'm out of luck except finding a Walmart open later in the day for another tire. If I'm traveling 500 miles from home, I guess I'm limited to what a tow company might oblige to do.

Are these scenarios likely? Rare but they do happen. 28 vehicles for me, spouse, 3 kids but it's only occurred twice. So I'll probably buy a full size kit with jack ($500) for the hybrid. It will be readily available in the garage when the spouse calls or I'll pack in the vehicle when we take long trips.

 

[dsgrey]

Just curious what you are picturing: four badass 37s and a whimpy donut on the tailgate? Seems like an odd place for an owner to economize.

It's a frequent site unfortunately. I recently changed from OEM to what I consider my ongoing tire tread and size. Slightly taller and wider tire but I went ahead and bought the 5 tire too.

 

[J0E]

Just curious what you are picturing: four badass 37s and a whimpy donut on the tailgate? Seems like an odd place for an owner to economize.

No, the stock 33" full size (for stock) spare.

As mentioned previously, wheeled recently with my buddy that used his 33" spare, finished the run, and drove home. Given flat and hence small spare was on the front, in 2 WD no problem.

I have a non-Jeep hybrid that doesn't have a spare. Comes with an inflator with fix-a-flat and that bothers me.

So I'll probably buy a full size kit with jack ($500) for the hybrid. It will be readily available in the garage when the spouse calls or I'll pack in the vehicle when we take long trips.

Many new cars don't come with a spare. I got a 2" cut in my Leaf. I was shocked when the fix a flat worked good enough for me to limp home. Why buy a full size spare for the garage? I'm getting a donut spare which I can secure in the hatch. Donut spares are cheap at junkyards.

 

[BDinTX]

If you can't afford a same size spare maybe you shouldn't get the bigger tires.

 

[J0E]

If you can't afford a same size spare maybe you shouldn't get the bigger tires.

Why make these moral judgements? It's not a matter of affording, it's a risk benefit analysis. It's ultra low risk to carry a mismatched spare.

I know lots of guys who wheel with a mismatched spare. A few who go without a spare and know they can use one of our spares.

 

[BDinTX]

lol man it sounds like you're gonna keep arguing with whoever will give you attention. Let me rephrase so I don't offend.

If you want to run 37's with a smaller spare, go for it.

Personally, I like using a single jack when I do my five tire rotation.
I also like, when I am 1500 miles from home solo, having a same sized spare. The closest offroad park to me is an hour away. The last time I threw a bead, I drove home worry free on my perfectly same sized spare with matching wheel. Then I hit discount tire the following Monday. I wasn't worried if my FAD would protect my diff, or if the Jeep was gonna pull to the right the whole way home.

I just don't understand the logic of having what is essentially a $50k toy and complaining about the price of one more tire and hinge gate reinforcement.

 

[J0E]

If you want to run 37's with a smaller spare, go for it.

I also like, when I am 1500 miles from home solo, having a same sized spare. The closest offroad park to me is an hour away. The last time I threw a bead, I drove home worry free on my perfectly same sized spare with matching wheel. Then I hit discount tire the following Monday. I wasn't worried if my FAD would protect my diff, or if the Jeep was gonna pull to the right the whole way home.

I just don't understand the logic of having what is essentially a $50k toy and complaining about the price of one more tire and hinge gate reinforcement.

Much better said. Why would you worry about the FAD protecting the diff unless you don't understand how it works? Even on the rear, it wouldn't do measurable damage coming home. That's why it's called a differential, it allow different rotations.

I agree totally with most of the rest of your statements. If you want to run with a smaller spare do it, personally I wouldn't because I've got the resources to not be inconvenienced. One of the JK's I wheel with doesn't have a spare. Last time he wanted to wheel in a remote spot with me I told him, find another JL or JK to join us, I'm reserving my spare for myself.

In the late 70's I went deep into a forest service road with my buddy elk hunting. I had tall skinny 7.50 16's that sailed right through the deep snow. He had aftermarket shorter and wider 15's and he struggled to follow me. Coming home when it was getting dark, like typical knuckleheaded high schoolers, we were going way too fast. He slid off the road and flattened both passenger side tires. It was snowing fast, leaving his rig overnight to fetch a matching spare meant he'd have to wait for spring to recover the vehicle. He used my spare. His spare didn't match either. He had I only one matching pair. He made it home.

To all you matching tire purists, what happens when you ruin a tire and the remaining 4 have 10% tread worn off? Do you buy a new set of 5 tires so you can have your perfect matching set? What about 30% wear? At what point do you toss 4 good worn tires and buy a new set of 5? 33%, 40%?

If you want to run 37's with a smaller spare, go for it.

Personally, I like using a single jack when I do my five tire rotation.

Get a BAOSHISHAN 4 Ton Bottle Jack 10-5/8" to 24" Lifting Range High Lift Double Ram Bottle Jack Hydraulic Bottle Jack and you can have a single jack. The BAOSHISHAN 4 Ton are hard to get right now.

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