AWD spare - distance and speed vs damage?

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Dec 26, 2021
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As mentioned in another thread, I have a GX460, which is full-time AWD. For directional tires, which can't easily be part of a five-tire rotation, what do people do for spares, and how far and fast can you go without damaging the transfer case or other components? Around town would be one thing, but on cross-country trips of close to a thousand miles in a day, the inability to finish the trip makes a directional spare unappealing.

Yes, I have read the manual. It is not helpful - it says "Do not mix tires of different makes, models or tread patterns. Also, do not mix tires of remarkably different treadwear." It also indicates a non-crossing rotation, with the spare included on the passenger side (and the dealer has never done so to my knowledge). Even following that, the spare (and the passenger side tires in general) will perforce have lower treadwear than the driver's side tires. What's "remarkably" different, and can a long road trip be finished? What if it's a driver's side flat and the spare is pointing the wrong way?

The original question remains - what do people do for spares in this situation? Is it simply not worth running directional tires on AWD?
 
Keep in mind that the use of a spare is supposed to be just good enough to get you to a tire shop to repair the original. Even if you were in the middle of nowhere, you shouldn’t be more than a couple hundred miles away from a shop that should be able to repair your flat or dismount and remount your directional tire. I don’t think that few hundred or even a few thousand miles will destroy your directional tire but your wet/snow traction will suffer.

As for what do I use on my AWD cars, I personally have the temporary use donuts that came with the cars. They are rubber and same diameter as the rest of the tires but that’s where the similarities end.
 
As mentioned in another thread, I have a GX460, which is full-time AWD. For directional tires, which can't easily be part of a five-tire rotation, what do people do for spares, and how far and fast can you go without damaging the transfer case or other components? Around town would be one thing, but on cross-country trips of close to a thousand miles in a day, the inability to finish the trip makes a directional spare unappealing.

Yes, I have read the manual. It is not helpful - it says "Do not mix tires of different makes, models or tread patterns. Also, do not mix tires of remarkably different treadwear." It also indicates a non-crossing rotation, with the spare included on the passenger side (and the dealer has never done so to my knowledge). Even following that, the spare (and the passenger side tires in general) will perforce have lower treadwear than the driver's side tires. What's "remarkably" different, and can a long road trip be finished? What if it's a driver's side flat and the spare is pointing the wrong way?

The original question remains - what do people do for spares in this situation? Is it simply not worth running directional tires on AWD?

If there's no centre diff they can blow in less than a hundred miles. But often it goes unnoticed and you just lose drive to the rear. more than 2mm wear difference means a warranty denial with Hyundai.
 
As mentioned in another thread, I have a GX460, which is full-time AWD. For directional tires, which can't easily be part of a five-tire rotation, what do people do for spares, and how far and fast can you go without damaging the transfer case or other components? Around town would be one thing, but on cross-country trips of close to a thousand miles in a day, the inability to finish the trip makes a directional spare unappealing.

Yes, I have read the manual. It is not helpful - it says "Do not mix tires of different makes, models or tread patterns. Also, do not mix tires of remarkably different treadwear." It also indicates a non-crossing rotation, with the spare included on the passenger side (and the dealer has never done so to my knowledge). Even following that, the spare (and the passenger side tires in general) will perforce have lower treadwear than the driver's side tires. What's "remarkably" different, and can a long road trip be finished? What if it's a driver's side flat and the spare is pointing the wrong way?

The original question remains - what do people do for spares in this situation? Is it simply not worth running directional tires on AWD?
First, running a directional tire in the wrong direction isn't a deal breaker. You just have to be aware that the performance will be diminished a bit - adjust driving accordingly.

To my mind, "Remarkably different treadwear" means 2/32nds or more. I assume they were intentionally vague for legal reasons. Besides we are talking about risk. This isn't a "Black/White" situation. It's about the odds of a drivetrain problem happening Drivetrain damage can be quite expensive, compared to replacing a set of tires. How much risk are you willing to take?
 
I can see tractor tires and snow tires being directional; race car and super performer tires too.

How can car companies produce such vulnerable systems for regular vehicles and how can people embrace them?
In other words, they make and market fragile AWD systems which are said to blow up when mismatched tires are used.
Then we discuss it as if it's unavoidable....like pine needles on the floor during Christmas.

Did you ever ask for a fragile AWD system? I didn't think so.
Do the car makers headline the fragility of their systems? No.

I'd love for all AWD vehicles to have a disengagement setting. That's all. That's all the OP would need too.
 
i understand that if you get a flat, a donut spare should be put on the front, and both rear tires should be the origininals, as the front has a standard diff, but the rears use a clutch-type diff, like a limited slip, and that’s what burns out with different size tires.
 
Thanks all. Think that makes me likelier to go for a non-directional and full rotation. I honestly have no idea if the GX has a center diff, though I'd hope so with its Prado base. Nor if the front has a standard diff or LSD.

And the appeal, to me, of a full-size spare is specifically to not have a road trip interrupted indefinitely by a flat requiring immediate repair. Around town is one thing, but on a thousand-mile drive, the need to find a place, open, potentially in a place like Sweetwater, TX or Trinidad, CO is... well, that would suck. Not as much as several grand of transmission repair though.

Especially with AWD being added to more and more vehicles, it seems like there should be a better way to handle this, and more clarity.
 
I think in this instance you should get ALL non-directional tires and do the full rotation. If you're regularly running three directional tires and one different, that different tire is now your weakest link.

Are you trying to create a situation where every time you buy tires, you buy five, and they're all evenly worn at the end of life? What about TPMS?

If you have a lot of life in your directional tires now, a spare you buy will start aging out by the time you buy 4 more matching ones. Maybe get a spare rim with a junk tire of the same size to get you through this set of tires?
 
modern AWD systems are "watered down" for better economy BUT the owner should surely KNOW what needs to be done if a tire change is necessary as it varies depending on your system. a good reason for a matching spare used in the rotation schedule. hopefully the dealer selling said brand would KNOW!!
 
I'd love for all AWD vehicles to have a disengagement setting. That's all. That's all the OP would need too.
my 08 Subaru Outback allowed you to pull a fuse to disable the rwd if you had a flat. Good tires go on front, spare goes on disabled back end.
 
modern AWD systems are "watered down" for better economy BUT the owner should surely KNOW what needs to be done if a tire change is necessary as it varies depending on your system. a good reason for a matching spare used in the rotation schedule. hopefully the dealer selling said brand would KNOW!!


How does a AWD system get “watered down”?
 
Thanks all. Think that makes me likelier to go for a non-directional and full rotation. I honestly have no idea if the GX has a center diff, though I'd hope so with its Prado base. Nor if the front has a standard diff or LSD.

And the appeal, to me, of a full-size spare is specifically to not have a road trip interrupted indefinitely by a flat requiring immediate repair. Around town is one thing, but on a thousand-mile drive, the need to find a place, open, potentially in a place like Sweetwater, TX or Trinidad, CO is... well, that would suck. Not as much as several grand of transmission repair though.

Especially with AWD being added to more and more vehicles, it seems like there should be a better way to handle this, and more clarity.
Read this thread that might give you more details on the GX. GX470 part time 4WD. My Sequoia had center diff that was open normally, you could run in AWD with it open and then lock it if needed. There has to be close to same version on the GX. You can't have a locked center diff if you drive on dry ground all the time (like you can't turn well in a old school 4WD when its engaged) no slip to accommodate the different tire speeds front vs. rear and will damage the system.

The appeal of the full size spare - still being able to tow, maybe get back to civilization from the off road path. Still find a convenient place to get it fixed. Small probability but what if you didn't get the flat fixed AND then caught a nail/metal/curb between Sweetwater and Trinidad? How would the roadtrip be interrupted? Cell service? Time for AAA to arrive? I have a cheap tire plug kit and small HF compressor in each car by spare tire/cubby, just in case. Murphy's laws will definitely be enforced.

Friend with AAA called for help with a flat on side of highway and they told them it would be at least 2-3 hours because everyone around had flats/dead batteries/accidents or other. It was a cold snowy day. I went and had her back on the road in 30 minutes from when she called. It took me 15 minutes to get there. Some places also restrict tow companies from certain parkways/highways that also makes that worse.
 
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If there's no centre diff they can blow in less than a hundred miles. But often it goes unnoticed and you just lose drive to the rear. more than 2mm wear difference means a warranty denial with Hyundai.
That's funny, some Hyundai dealers in the USA where adding rear temporary spare tires as much as 1.5 to 2 inches smaller off OEM tire diameter to AWD Kona's just so they could charge for it on a new car purchuse. My car had one of those, but my dealer had to get my car from another dealer as my car was one of only 3 silver Kona's in the USA at the time and I was willing to pay the $500 to get it shipped to me. That dealer added it to the car when they posted it for sale. Good thing I did not use it.
We saw about 4 people on the Kona forums that blew out their center diffs. Hyundai warranted them, but if I remember right there were a couple that had to fight for it. Could of be Hyundai Canada as they are known to deny any questionable warranty as default. Canada doesn't have the Magnuson-Moss Warranty Act like the USA has. They have some form of one, but I have to assume not as broad.

It is good to know the spec Hyundai goes by as I carry a full sized steel rimmed spare with a full sized smaller tire with the same diameter as my OEM speced tire. I keep it in there at all times as it is my low slung added weight for my car proper weight distribution for my suspension setup. Kona's need more weight in the rear even if it is has AWD and the added weight of the rear diff. I will have to do a string diameter check to see how far I am off from my mid level worn Michelin's. So as far as our US based standard of 1/32 measurement for tires. 1/32 = .79mm, 2/32 = 1.59mm, and 3/32 = 2.38mm. Good to see I have kept mine in the 2mm tolerance all this times. My wife's Rav4 unfortunately I have let go in the 3.0 mm spread area. I will have to keep from now on under the 2mm spec as I can only assume they all want it in that max spec spread.
 
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How does a AWD system get “watered down”?
“Slip n grip” type systems that only start sending power to the other axle once traction is lost, and then only a little bit at that. Though more modern systems are better, like Stellantis’s/FCA’s AWD system on the Challenger/Charger/300, it runs RWD until it’s below 40, the windshield wipers are on for a “significant” amount of time, auto stick is being used, it’s in sport mode, and/or it detects wheel spin.

I also remember watching a video of an older Honda CR-V or Pilot (can’t remember which) where they put the front wheels on rollers to force the AWD on and see if it could push itself off the rollers, it was unable to do so.
 
I put my own FWD car on rollers aswell. 1 front wheel of course. The 2 most benign ESP modes wouldn't let it drive off the rollers, but sports mode mimicks an LSD and as soon as the clutch was fully engaged it drove off like they weren't there.

With a 70/30 weight bias I probably have nothing to gain from a simple AWD system, except headaches..
 
On my wife’s GX I included the full size spare in the rotation and ran non-directional Michelins. There must’ve been a TPMS sensor in it as I never messed with anything. Never had to replace all 5 tires as they wore so well I likely would’ve gotten 90,000 miles or more out of 5.
 
On my wife’s GX I included the full size spare in the rotation and ran non-directional Michelins. There must’ve been a TPMS sensor in it as I never messed with anything. Never had to replace all 5 tires as they wore so well I likely would’ve gotten 90,000 miles or more out of 5.

There's definitely a sensor in the spare as the light will go on when that one goes low and you go crazy trying to figure out which of the four is bad.

Thinking I'll go in that direction for mine, probably with the Pirellis. Thanks for the input.
 
“Slip n grip” type systems that only start sending power to the other axle once traction is lost, and then only a little bit at that. Though more modern systems are better, like Stellantis’s/FCA’s AWD system on the Challenger/Charger/300, it runs RWD until it’s below 40, the windshield wipers are on for a “significant” amount of time, auto stick is being used, it’s in sport mode, and/or it detects wheel spin.

I also remember watching a video of an older Honda CR-V or Pilot (can’t remember which) where they put the front wheels on rollers to force the AWD on and see if it could push itself off the rollers, it was unable to do so.
It’s the CR-V, previous generation that failed the front wheels on rollers test
 
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