NA - All wheel drive car and replacing tires

Fiveslide

Fiveslide

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Fiveslide
My wife cut a tire sidewall on her Element. I know we have a lot of AWD car owners here, I have no experience with full time all wheel drive.

The remaining tires might be half worn. Would you replace only the one that got cut? Both on the same side? All four?

All I know is significant differences in tire sizes are a no-no. Are small differences, simply due to wear on three and one brand new, a big deal?
 
Tire Rack offers a ‘shaving’ service to get the new tire down to matching the old ones. Yes, you lose half the life off the new one but it beats buying four.
 
We have multiple subaru's. The official guideline I have read for subarus is maximum 2/32 tread depth difference. Otherwise the transmission will interpret it as tire slip and attempt to compensate. Either change all 4 or measure your tread depth, and shop ebay for your same tire used at an acceptable tread depth range.
 
Just replace all the tires.

If your existing tires are already half gone and they arnt super a expensive tire, seems like more effort than it’s worth to try to match one tire
 
If the other 3 are half tread, change them all out. Your drivetrain will thank you by not requiring a bunch of expensive future repairs.

I rotate mine front-to-back, same side only, every second oil change on my AWD and 4X4s.
 
I buy hazard insurance for my tires when I get them. It will replace all four if one is damaged.

That said, I think it's a myth.

Almost every all wheel drive car uses a front/rear torque split that is not 50/50. In other words if you lifted the car off the ground the front and rear wheels would spin at different speeds - intentionally causing the tires/axles to fight each other in the exact same way that having different size tires would.

My current car has "staggered rims", meaning the front and back wheel/tire sizes are intentionally different (no rotation possible). The fact that the same car can be purchased with all four being the same size without changing anything supports my argument.

If your car has a spare it's probably not even close to the same outer diameter as the remaining three. How is that possible?

Any modern all wheel drive vehicle uses a form of clutch (often) called a Haldex valve. It varies the torque split from front to back. So there is slip built in, and it is calculated on the fly based on speed sensors from each wheel. If this clutch pack equalized the wheel speeds there would be no torque split.
I can see arguing that you should consider replacing the other tire on the same axle but it would have to be extreme enough for the wheel speed sensor differences before it caused an issue.

I'll wait right here while someone shows me a repair bill for their drivetrain that was caused by one bad tire.

Naturally someone will want to know why I buy hazard insurance if I believe this. It's because I get a $1200 set of tires for the $100, and that has happened enough times to be well worth it.
 
The manufacturer will have a spec. for matching tires on the same axle. You may have to shave a new tire to get within spec.

Sometimes when I have put two new ones on, I keep the good one of the pair and use it next time I need to replace a tire where the mate has some tread ware. Sometimes that is a money saver.
 
Depends on the AWD. Subaru with mechanical limited slip differential are picky. Mercedes with the anti-lock brake controlled 4-matic are not. Read the manual for your car, ask a factory certified mechanic. Different systems, different specs.
 
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Besides it’s a excuse to get some new shoes, or get rid of run flats if you have them.

The Michelin AS3+ are REALLY nice

For a little le$$, Goodyear assurances all seasons (with the soy based rubber that doesn’t get hard in the cold).
 
I'd probably replace them if they're half-gone anyway. Either that or search eBay / Craigslist / junkyards / tire shops for the same model tire with about the same tread remaining.

I had a very good experience with Goodyear.com recently. I bought four Assurance WeatherReady tires and had them arrange mounting and balancing locally. It was all done quite efficiently with no drama at all, and the $225.00 rebate was processed in about two weeks.

I'm also very happy with the tires themselves so far, but I'm waiting on the first snow to make a more definitive evaluation. My hope is that they'll perform well enough that I can limit the use of the studded winter tires to the coldest months, when ice becomes a consideration.

Rich
 
AWD general rules are to match circumferences within some factory specs. At 50% treadwear, get 4 new or take Rich’s advice and buy used. A lot of people say you can buy a new tire and shave it, but I never liked the idea of buying a new tire and cutting it down to 50% right away..

The mini spare is not the same circumference, but my manual says it’s only for use on the back and only for limited miles at a limited speed.
 
1B9393C2-1DD1-4ACA-9C57-8BFE12A1F186.jpeg Here’s y’all’s excuse to get some big knobby tires for your Elephant.

Anyone else noticed how much the just released Land Rover Defender resembles an Element?
 
I over estimated the wear on the tires. I think I've decided to do the two on the front. I got a tread depth gauge. According to specs we've only worn 2/32's off the tires, or 22% of the useful life of the tire.

These tires have been on this car for just over 2 years. Anyone still think the difference is significant enough to warrant replacement of all four rather than just two on the same axle? I can still get the exact same tire, just have to order them.
 
wrbix said:
View attachment 78479 Here’s y’all’s excuse to get some big knobby tires for your Elephant.

Anyone else noticed how much the just released Land Rover Defender resembles an Element?
Click to expand...

Ten years ago, I'd have put some mud tires on it.:D

I can't stand tire noise on the highway these days. On anything like this, I would never put knobby tires on it. I have some Goodyear All terrain tires on my old Chevy farm truck, not a daily driver, that's about as aggressive as I'll ever go these days.
 
James331 said:
Besides it’s a excuse to get some new shoes, or get rid of run flats if you have them.

The Michelin AS3+ are REALLY nice

For a little le$$, Goodyear assurances all seasons (with the soy based rubber that doesn’t get hard in the cold).
Click to expand...
Can I assume you’re running the AS3s? How quiet are they? I have two vehicles that will need new shoes before winter. My wife’s Volvo XC 60 is currently running the factory Pirelli Scorpions, and they are the noisiest tires ive driven in years. Truly annoying. The Mercedes has summer tires on it, so it will be useless unless I get some all seasons on it. I want grip, but I hate excessive road noise.
 
Fiveslide said:
I over estimated the wear on the tires. I think I've decided to do the two on the front. I got a tread depth gauge. According to specs we've only worn 2/32's off the tires, or 22% of the useful life of the tire.

These tires have been on this car for just over 2 years. Anyone still think the difference is significant enough to warrant replacement of all four rather than just two on the same axle? I can still get the exact same tire, just have to order them.
Click to expand...

One post on the Subaru owners form has this from the Subaru factory tech support (2010):

>>
"The Techline continues to receive calls from Technicians who have performed all types of unsuccessful repairs to transmissions with a “binding on turns” concern from the Customer. One of the first questions we will ask is whether or not the tire circumferences have been measured. All too often the answer is no. It is extremely important when diagnosing a transfer clutch-related concern, the tires must be one of the first variables you rule out. Remember, all 4 tires should be within approximately ¼" of each other in circumference when measured at the center of the tread. Otherwise, binding issues can result (or re-occur) due to the ratio imbalance caused by mis-matched tires. A quick keyword search on STIS of “Binding on Turns” will return a list of other bulletins and TIPS articles on this subject."
<<

I didn't do the math, but someone else on the forum says:

>>
A 1/4 inch difference in circumference in a typical 17 inch tire used on Subarus translates to between 1/32 and 2/32 of an inch difference in tread depth (or radius). It's not much.
<<

In your case, with 2/32 worn off you are right about at that limit. Replacing the pair is probably going to be OK.

Even though Subaru owner manuals specifically says tires need to be the same circumference, they don't give a tolerance. The only thing I've ever seen is what I pasted above.
 
DaleB said:
Can I assume you’re running the AS3s? How quiet are they? I have two vehicles that will need new shoes before winter. My wife’s Volvo XC 60 is currently running the factory Pirelli Scorpions, and they are the noisiest tires ive driven in years. Truly annoying. The Mercedes has summer tires on it, so it will be useless unless I get some all seasons on it. I want grip, but I hate excessive road noise.
Click to expand...

Not too bad, they are low profile on a car with firm suspension. But ditching the runflats made a big difference in itself.
 
Matthew said:
One post on the Subaru owners form has this from the Subaru factory tech support (2010):

>>
"The Techline continues to receive calls from Technicians who have performed all types of unsuccessful repairs to transmissions with a “binding on turns” concern from the Customer. One of the first questions we will ask is whether or not the tire circumferences have been measured. All too often the answer is no. It is extremely important when diagnosing a transfer clutch-related concern, the tires must be one of the first variables you rule out. Remember, all 4 tires should be within approximately ¼" of each other in circumference when measured at the center of the tread. Otherwise, binding issues can result (or re-occur) due to the ratio imbalance caused by mis-matched tires. A quick keyword search on STIS of “Binding on Turns” will return a list of other bulletins and TIPS articles on this subject."
<<

I didn't do the math, but someone else on the forum says:

>>
A 1/4 inch difference in circumference in a typical 17 inch tire used on Subarus translates to between 1/32 and 2/32 of an inch difference in tread depth (or radius). It's not much.
<<

In your case, with 2/32 worn off you are right about at that limit. Replacing the pair is probably going to be OK.

Even though Subaru owner manuals specifically says tires need to be the same circumference, they don't give a tolerance. The only thing I've ever seen is what I pasted above.
Click to expand...

From all I've read, the Honda Element AWD isn't full time, it's more forgiving than Subaru's system.

I can't believe I'm agonizing so much over this. With rebates, a whole set will be $160 more than just two matching the rear. But I hate to be so wasteful and replace something with so much life left.

I guess I could ask to keep the three good tires and sell them to both recoup some of the money and make sure they don't immediately get disposed of. What are the current recycling practices with tires or are the going in landfills?
 
Fiveslide said:
From all I've read, the Honda Element AWD isn't full time, it's more forgiving than Subaru's system.

I can't believe I'm agonizing so much over this. With rebates, a whole set will be $160 more than just two matching the rear. But I hate to be so wasteful and replace something with so much life left.

I guess I could ask to keep the three good tires and sell them to both recoup some of the money and make sure they don't immediately get disposed of. What are the current recycling practices with tires or are the going in landfills?
Click to expand...
Since you'll pay an extra $4 or so per tire for a "disposal fee", I think they get shredded and re-used.

You could keep one as a full sized spare, then you'd only need to figure out what to do with 2.
 
Matthew said:
Since you'll pay an extra $4 or so per tire for a "disposal fee", I think they get shredded and re-used.

You could keep one as a full sized spare, then you'd only need to figure out what to do with 2.
Click to expand...

I just ordered a whole set. I bet I can get $50 a piece for the old ones considering they're in such good shape and the same tires new are $135 each.

Done agonizing.

Thank you all for your time and input.
 
Nope. Home in New Mexico working through a few health problems.

This is why it is important for folks that fly for a living to have a fall back plan.
 
I used to own a Subaru, and I am cheap.

The time I needed to replace one tire, I bought a used one off of Ebay, and had it mounted. My tires probably had around 1/4th of the life left, but I wasn't sure if I was going to keep it (it had 260K miles on it at the time), and I found a matching tire, within spec (3/32s tread difference, if I recall correctly), for under $40 shipped (a new tire was about $100), then I was hit with another $20 for mount and balance.

But, I had a spare mode of transport, and I didn't have to drive the Subaru while I waited for shipping.
 
Thanks for this thread.
I am going to search high and low for a non-AWD vehicle when it comes time to re-truck.
(That and a standard tranny, lol)
 
Let'sgoflying! said:
Thanks for this thread.
I am going to search high and low for a non-AWD vehicle when it comes time to re-truck.
(That and a standard tranny, lol)
Click to expand...

I love AWD, but I have a reason for having it.

If I was in Texas I’d just go RWD shy of off roading .
 
James331 said:
I love AWD, but I have a reason for having it.

If I was in Texas I’d just go RWD shy of off roading .
Click to expand...

We just moved into a new house in southern Virginia in August. It is on a private road, about a mile and a half from the paved road that will be scraped when it snows. The AWD MIGHT come in handy sometime, but we certainly haven't needed it before.
 
Let'sgoflying! said:
Thanks for this thread.
I am going to search high and low for a non-AWD vehicle when it comes time to re-truck.
(That and a standard tranny, lol)
Click to expand...
I wouldn’t even consider a truck without some form of 4 wheel drive (and, yes, I know the difference AWD vs FWD).....a rear wheel drive pickup won’t even climb a dew covered grassy hillside.
Get a truck with lockable front hubs.

Oh, and BTW, real trucks don’t have spark plugs ;)
 
Interesting thread.

Both our Flex and Ridgeline are AWD. I replaced a single front tire on the Flex and, more recently, both front tires on the Ridgeline. Gave no thought to slightly different circumferences, and neither tire place brought it up.

Just not going to worry about it.
 
DaleB said:
Can I assume you’re running the AS3s? How quiet are they? I have two vehicles that will need new shoes before winter. My wife’s Volvo XC 60 is currently running the factory Pirelli Scorpions, and they are the noisiest tires ive driven in years. Truly annoying. The Mercedes has summer tires on it, so it will be useless unless I get some all seasons on it. I want grip, but I hate excessive road noise.
Click to expand...
There is more than one type of Scorpion. The scorpion Verde which I currently have on my car are known to get very noisy as they wear. Mine are around 15k miles and okay so far. I'll buy something else to replace them when the time comes.

The AS3 have a great reputation
 
FastEddieB said:
Interesting thread.

Both our Flex and Ridgeline are AWD. I replaced a single front tire on the Flex and, more recently, both front tires on the Ridgeline. Gave no thought to slightly different circumferences, and neither tire place brought it up.

Just not going to worry about it.
Click to expand...

I worried about it way more than I probably should have. In the end, with the rebates and selling the barely used tires, I think I can about break even with buying a whole set over just two.

My wife would take my truck and come home to find me in the same spot, on my phone, still tire shopping. I sat here for hours checking prices, comparing tires, sales, reviews, rebates, installation costs, different 2 and 4 tire scenarios. I've always said I have more time than money.

I also thought about resale value, mismatched tires is a turn off for me if I'm buying. We don't plan on selling, but you never know.

What is really going to suck is buying a set for the Titan in a month or so. They'll be twice the price, I imagine.
 
Given that Element(along with all other "4WD" Honda cars/trucks) uses Honda's Real-Time 4WD system(alternatively known as FWD with on-demand AWD), as long as your front axle has same size tires, you should be fine mechanically. Rear is not engaged until front is slipping(which is very rare in normal driving) and when that happens(say in snow), it does not matter if tires in the back a not the same size as in front.

I would still try to keep tires on the same axle the same size, type, and with the same thread depth, however. For braking stability mostly. It also helps with even traction under acceleration in slippery conditions.

Edit: In addition, I suspect that both rear and front differentials on that car are open, so mechanically, there shouldn't be any issues running slightly different size tires left to right. But as I said above, it's not a good idea from driving dynamics(same as any 2wd car)
 
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genna said:
Given that Element(along with all other "4WD" Honda cars/trucks) uses Honda's Real-Time 4WD system(alternatively known as FWD with on-demand AWD), as long as your front axle has same size tires, you should be fine mechanically. Rear is not engaged until front is slipping(which is very rare in normal driving) and when that happens(say in snow), it does not matter if tires in the back a not the same size as in front.

I would still try to keep tires on the same axle the same size, type, and with the same thread depth, however. For braking stability mostly. It also helps with even traction under acceleration in slippery conditions.

Edit: In addition, I suspect that both rear and front differentials on that car are open, so mechanically, there shouldn't be any issues running slightly different size tires left to right. But as I said above, it's not a good idea from driving dynamics(same as any 2wd car)
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Ewwwww

I had a car like that overseas once, not a fan.
Subie AWD is where it’s at.
 
James331 said:
Ewwwww

I had a car like that overseas once, not a fan.
Subie AWD is where it’s at.
Click to expand...

Subies(the current crop) have their own issues. But yeah, their AWD is better(and you do need to keep tires similar on them), but still has limitations with front and rear open diffs.

However, symmetrical(or even continuous) AWD is a rare exception in cars these days. Vast majority are 2wd systems(mostly FWD) with electronic engagement of the other axle when slip is detected.
 
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