I cant find any post or manual from Acura on 2 tire replacement. I got new tires last year but 1 got screws multiple times so just want to replace 2 tires.Some say its not recommended due to damage to AWD system since tires can be different threads...how true is that.
Would be ok to only replace 2 tires on AWD despite different age.

 

Nevermind,I found link to RL manual which Ive never seen before which explains all of details in car including tires so Acura say you can only replace 2 if needed in pairs.
Here is link if anyone needs it.

https://www.acura.com/assets/OWNERLI...ra/2006_RL.pdf

 

Yes, though I have replaced just 1 tire because I had a nail in the sidewall of a fairly new tire (4,000 miles) with the same brand/size...otherwise I would replace in pairs or all 4.
Page 386:
It is best to replace all four tires at the same time. If that is not possible or necessary, replace the two front tires or two rear tires as a pair. Replacing just one tire can seriously affect your vehicle’s handling. Replace your tires with radial tires of Wheels: the same size, load range, speed rating, and maximum cold tire pressure rating (as shown on the tire’s sidewall). Using tires of a different size or construction can cause the ABS and vehicle stability assist system (VSA) to work inconsistently. If you ever need to replace a wheel, make sure the wheel’s specifications match those of the original wheel that came on your vehicle. Replacement wheels are available at your Acura dealer

 

It does not mention anything about AWD system being affected by different tires.Either way Ill just replace 2 as pair.

 

Had a relatively new tire go when I struck some road junk. Discount tire guys insisted I had to replace in pairs and used Subaru's very strict policy as an example. I called the Acura dealer I use, and the techs told me there are so many sensors on that car, replacing just one tire is absolutely no problem. Just sayin'....

 

On any car when tires a bit old, they will never be of same tread depth. If the tires are within 2/32nds difference from each other, it is okay to replace only one (for example 3 tires are at 7/32 and new is 9/32). I did that to my 2010 mdx and it was fine. Remember that your spare tire is always less than the total diameter of full other tires, so it is okay to have some tread difference (abiut 2/32nds) across all 4 tires

 

Please cite your source for the 2/32nds figure.

 

check out this page https://www.shadetreeautomotive.net/...s-on-awd-cars/

Also check this thread: https://acurazine.com/forums/4g-tl-t...e-tire-960691/

IMO 2/32 is not a big difference between all 4 tires and our cars are designed to overdrive the outer rear wheel by 5% so shawd is always over rotating the outer tire at turns.

 

OK, well we have lots of opinions, and yet even Acura doesn't state a definitive spec on when tires need to be replaced based on tread depth, right?

So I guess the best way is to call a dealer with the specific question. As I said, Subaru won't permit any differences, so I suppose it's system-dependent?

 

Tyres ought to be replaced in sets due to the difference in handling/grip between old & new rubber.

Unless you drive like I do, you'll likely not notice the difference.

In terms of rolling radius, the difference between old & new is not even equivalent to driving around a slight curve in the road, so the differential can handle it.

Remember, the KB transmits the drive via epicyclic gears and the clutch plates merely vary the degree of overdrive by slipping. I could foresee a car with clutch-drive constantly slipping might possibly increase wear over time. That'd be one of the latest Acura diffs, then,

But if you're Miss Daisy, the rear clutches will be pretty 'loose' most of the time anyway.

 

The various myths about AWD systems all needing identical tyres started because some of the early systems in the 90s (Volvo for one) could be easily destroyed by running mismatched tyres. So some manufacturers (like Volvo) had strict rules about tyre matching - these rules don't apply to every AWD system out there, some are more tolerant than others, and the general concept is a relic from 20-30 years ago. I wouldn't worry about it on any modern AWD system, and as per the manual above there's no particular restrictions noted by Acura/Honda for ours.

 

Yeah - it's usually got to be something extreme though.

The garage put the wrong-profile fronts on a friend's 350 SL and that confused the anti-skid a bit. Kept going into limp mode on a run...

Having had countless e-modules replaced under warranty, he finally rejected the car.

It was only then the dealer noticed...

 

This is a little misleading. As mentioned earlier in this thread, the manual clearly states on page 386, "It is best to replace all four tires at the same time. If that is not possible or necessary, replace the two front tires or two rear tires as a pair. Replacing just one tire can seriously affect your vehicle’s handling." I don't see this as an assurance from Acura that mismatched tires will have no adverse effect on our "Super Handling All Wheel Drive" system.

 

I agree with replacing 2 tires, if it was up to me i would replace all 4 if they are old and worn. But sometimes it doesn't make sense to replace just one tire if other three are within 2/32 of each other. For eg. If all three tires are around 7/32 you could find a used tire with similar specs or new with 9/32nds. That 2/32 on new tire will wear off pretty fast as compared to old 3 tires. Other thing is i would replace the tire with same make and model as others. I did that with mdx when i had a blowout, 3 Michelin xice snows were at 7-8/32nds and replacement was 9/32. I drove last winter with that setup in Snow and never had any issues.

 

OK, except for the gross dealer error in the Mercedes story (which, BTW didn't even really damage anything), as anyone heard or experienced a damage-resulting problem with their Acura and tire episodes like we are discussing.....or is this just an interesting conversation bereft of real experience??

 

Sorry, I thought that replacing in pairs was just a given - that applies to any car, no matter what the drivetrain. Running unmatched tyres on the same axle is generally a bad idea when you need to make emergency maneuvers...
I wasn't trying to say that replacing one single tyre with something unmatched was OK 😁

It's also worth noting that the space-saver spare tyre in your trunk is dramatically different to the other three tyres - and you can use this tyre only temporarily at lower speeds. I had to use mine at the weekend to take a punctured tyre for repair - it made various whirring sounds come from the drivetrain, I wouldn't want to keep it on there any longer than absolutely necessary !!

 

Yes - with a rear puncture on an S2000, you put the SS on the front and a front wheel on the back! But that has a Torsen-type diff and rolling radius is important if you don't want to kill it.

The main concern is old tyres go hard & not grippy like new ones, so asymmetric handling could be an issue if not replaced in pairs. Or all four, preferably.

Especially if you've got some hi-po tyres and a cheap 'economy' one - don't mix tyre types, even of the same brand. I found that out on my X1/9, when the spare was a cheap economy tyre and it resulted in massive oversteer on the first bend I encountered. It was very controllable, at the comparatively low speed.

FWIW, I have 3 x Advan V105s and one V107, following a puncture in an almost-new tyre (sigh). It appears to be a slight tread pattern update, so I've not really noticed any oversteer-asymmetry on the Leg End.