Spare Tire Offset Questions

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FLGeezer

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New to me JK did not come with a spare. Looking at getting new tires all way round plus adding a spare (MTs to ATs). Looking at buying a matching rim for the spare but the rims I have are hard to find. So, some questions:
(By the way, I'm an old fart and have always called them "rims" and not "wheels". A "wheel" was the total package...tire + rim = wheel. Apparently somewhere in time people started calling "rims" as "wheels".)

1. You guys running a matching rim on your spare? If so, do you include the spare in your rotation scheme?

2. To be honest, until I started looking at Jeeps I never heard of wheel offset. I just always bought the recommended tires for my vehicles. So, I'm a bit confused. I did find one source for my rims but one is a positive offset and one is a negative: https://www.tiresandwheels.com/catalog.php?cat_id=171&scat_id=1472&c-vid=126559 Not sure but I'm thinking mine are negative, after Googling a bunch. (btw, my tires are 35x12.5x17). Here's photos....negative, right?

IMG_0229.jpg


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My spare wheel/rim matches the other 4 (Moto Metal Model 962), but my spare is a Toyo MT 35x12.5.
I put new tires on during COVID and it took forever to get 4 BFG TA KO2s, let alone a spare. So the tires don't match, but it's covered, so I don't care.
 
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Mine and my wife’s match and I do the five tire rotation.

So no expert here, but given the pictures and the size of tire you have I “suspect” the jeep has spacers installed. I say that as looking at how the rims mount I am not sure they are set in enough. This is only guess, but easy for you to find out. You might be able to see inside the rim and see if there is a spacer, or might have to pull the wheel to see. Seems people are 50/50 on spacers so it can open a can of worms. I am no spacer guy myself, one less thing to worry about.
 
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Mine came with 5 matching Pro Comp rims, but three different and nearly new brands of MT tires. Momma got real tired of the howl and we swapped them out for 35” Atturo Trail Blades XTs for the drive home. Old 33s are stashed in the storage locker to sell when we go back south. They’ll be rotated properly with the spare included.
 
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FLGeezer said:
New to me JK did not come with a spare. Looking at getting new tires all way round plus adding a spare (MTs to ATs). Looking at buying a matching rim for the spare but the rims I have are hard to find. So, some questions:
(By the way, I'm an old fart and have always called them "rims" and not "wheels". A "wheel" was the total package...tire + rim = wheel. Apparently somewhere in time people started calling "rims" as "wheels".)
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You've got it backwards. A wheel has always been a wheel. A rim is (and always has been) the outermost portion. Originally it was the metal rim placed on a wooden wheel to keep the wood from immediately falling apart. Now it is the outermost portion of a wheel, that contacts the tire. A wheel and tire are... a wheel and tire. You've just been using the wrong terminology longer than most.
FLGeezer said:
1. You guys running a matching rim on your spare?
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I have a matching wheel on my spare, yes.
FLGeezer said:
If so, do you include the spare in your rotation scheme?
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No. Tire rotation is intended to balance out uneven wear between tires. If my tires wear unevenly, I fix whatever is causing that to happen. So I do not rotate my tires; they wear evenly. 60 years ago, manufacturing tolerances were significantly looser, and tire rotation was absolutely necessary. Not so today. I think people do it because they've always done it. I call it cultural inertia.
FLGeezer said:
2. To be honest, until I started looking at Jeeps I never heard of wheel offset. I just always bought the recommended tires for my vehicles. So, I'm a bit confused. I did find one source for my rims but one is a positive offset and one is a negative: https://www.tiresandwheels.com/catalog.php?cat_id=171&scat_id=1472&c-vid=126559 Not sure but I'm thinking mine are negative, after Googling a bunch. (btw, my tires are 35x12.5x17). Here's photos....negative, right?
Click to expand...
It is impossible to tell what backspacing and offset you have from pictures, but I suspect you have inadequate backspacing which someone tried to correct by using spacers. Nasty.

Wheel offset is the distance from the mounting surface to the centerline of the wheel. On the other hand, backspacing is the distance from the mounting surface to the wheel's back lip. And the only way to find out what you have is to take them off, break out a straight edge and a ruler, and start measuring.

With 35" tires on a JK, you want about 4.25" backspacing and an offset of +25 to +50. This will minimize rub and maintain proper alignment and avoid premature failure of suspension components.
 
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Danarch said:
Mine and my wife’s match and I do the five tire rotation.

So no expert here, but given the pictures and the size of tire you have I “suspect” the jeep has spacers installed. I say that as looking at how the rims mount I am not sure they are set in enough. This is only guess, but easy for you to find out. You might be able to see inside the rim and see if there is a spacer, or might have to pull the wheel to see. Seems people are 50/50 on spacers so it can open a can of worms. I am no spacer guy myself, one less thing to worry about.
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I have always used the five-tire rotation; my tires lasted up to 60K before I bought a brand new takeoff 5-tire set from a 2022 JL - the owner immediately wanted to change the rim and tires. The total cost for a five brand-new takeoff was $1200 (KO2s).
 
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Five-tire rotation is the way I would recommend, though if the spare tire is a different make, that might be a little bit irritating. I have four Firestone Destination M/T2a's on the road, but the spare is BFG Mud Terrain T/A KM2. My suspicion is that all five matched, but the dealer swapped out the four on floor, but neglected the spare. The manual (my 2016) recommends five-way rotation.
 
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Duster said:
Five-tire rotation is the way I would recommend, though if the spare tire is a different make, that might be a little bit irritating. I have four Firestone Destination M/T2a's on the road, but the spare is BFG Mud Terrain T/A KM2. My suspicion is that all five matched, but the dealer swapped out the four on floor, but neglected the spare. The manual (my 2016) recommends five-way rotation.
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I don't put much stock in the owners manual. It used to be that the manual told you how to set valve lash. Now it tells you not to drink the antifreeze.
 
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Dirty Dog said:
Solid lifter cams are still a thing. Mostly by performance enthusiasts, but they're still a thing...
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Yeah, but the engines with ‘em ain’t stock from the factory no more. The folks that run them, put them in.

I’ve dealt with it in my Chevelles back in the day. ‘66 SS 396 and a Booth Arons SB 327 in a ‘72. 2-3 times a year, the valve covers got pulled.
 
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FLGeezer said:
New to me JK did not come with a spare. Looking at getting new tires all way round plus adding a spare (MTs to ATs). Looking at buying a matching rim for the spare but the rims I have are hard to find. So, some questions:
(By the way, I'm an old fart and have always called them "rims" and not "wheels". A "wheel" was the total package...tire + rim = wheel. Apparently somewhere in time people started calling "rims" as "wheels".)

1. You guys running a matching rim on your spare? If so, do you include the spare in your rotation scheme?

2. To be honest, until I started looking at Jeeps I never heard of wheel offset. I just always bought the recommended tires for my vehicles. So, I'm a bit confused. I did find one source for my rims but one is a positive offset and one is a negative: https://www.tiresandwheels.com/catalog.php?cat_id=171&scat_id=1472&c-vid=126559 Not sure but I'm thinking mine are negative, after Googling a bunch. (btw, my tires are 35x12.5x17). Here's photos....negative, right?

View attachment 124141

View attachment 124142
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Flares have changed over the years .
But judging by the pic it looks like your sticking out beyond the flare as much as I do .
1 1/2 inches .
I’m running 2008 Saraha
Rims 17x9
4.5 “ Backspacing .
If you measure from rim mounting surface to the lip . You can see what the backspacing is . If 4.5” your good to go . Will give sufficient clearance for 1 ton ends , 35 or 37” tires , after market control arms etc etc .
As a few already mentioned it’s a good idea to include spare in your rotations .
Somebody up above mentioned rotating not required . That’s one of the more sillier things I have read on here . Your front tires wear more & differently than the rears because of all the turning you do . Any reputable shop will suggest rotating regularily . My tire shop offers free rotating . So a bit of a bonus . Every 2nd oil change cruise by the shop and get tires done .
 
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Duster said:
Five-tire rotation is the way I would recommend, though if the spare tire is a different make, that might be a little bit irritating. I have four Firestone Destination M/T2a's on the road, but the spare is BFG Mud Terrain T/A KM2. My suspicion is that all five matched, but the dealer swapped out the four on floor, but neglected the spare. The manual (my 2016) recommends five-way rotation.
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This is my main argument for doing a five tire rotation. (Not the manual) If you only do four tire, then you are stuck with a particular size / brand of tire or having a non matching one bolted to the rear of the vehicle limiting its usefulness.

https://tiresize.com/calculator/

This website has a great collection of tools for figuring out tire / rim / wheel stuff. It may have a way to measure what you have. The big problem in finding a matching wheel/rim is that they may have stopped making that one. At the least, your wheels may have a stock or model name / number on the inside that you can plug into the companies website.
 
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Yeah, I've been on that site a lot as I'm looking at replacing my M/Ts with A/Ts. And they HAVE discontinued my rims but I found a site that has some but one is a positive offset and one is a negative, which is why I was asking about offsets.
 
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