Using tires with different tread depths?

[996GT2]

Here's the situation. My Accord had a flat about a year ago, and one tire was replaced with a brand new one. All 4 tires on the car are the same brand and model (Michelin Energy MXV4).

The 2 tires in the front currently have about 4/32" of thread remaining. Both show similar levels of wear and thus have similar tread depths.

One rear tire has between 4/32" and 5/32" of tread depth, but the other one, which was replaced last year, has about 8/32" of tread left.

Since the rears are less worn than the fronts, would it be safe to rotate the 2 rear tires into the front, considering the different tread depths (5/32" vs 8/32")? I know I'm due for tires within the next year or so, but I'd like to get a little more out of this current set if possible. There's no LSD in an Accord so there shouldn't be any issues with the drive train by running front tires with different tread depths, right?

 

[kitatech]

I can't answer your question, but it's a circumstance I've just this week decided to try to avoid by ordering a 5th tire like the other 4 and rotate them all to try to maintain an equal wear history...very difficult in my case as the tires are UNIdirectional...

 

[lakedude]

I'm pretty sure it is generally bad to have 2 different sized tires on the front of a front wheel drive car.

I bet the instructions say to put the high pressure spare on the back so that the 2 front tires will be the same size.

 

[lakedude]

So I just checked the owner's manual for a 2010 Accord and it says nothing about putting the spare in back. In fact the example shows the spare being mounted in the front.

This would seem to indicate that the tranny can handle different sized wheels/tires.

 

[Kelvrick]

Can you go pay a tire shop 10-20 to shave the 8/32 tire down to 5/32?

 

[deadken]

It is FINE to rotate your tires, even with the slightly different tread depths.

A few things to consider:

When replacing a pair of tires, most shops will install the newest tires on the rear of a car. The thought is that if the car is to lose traction, you would get understeer with the better tires in the rear. If you put the newest tires in the front you could get oversteer which would be more difficult for the driver* to regain control of.

Assuming you don't have unidirectional tires: When rotating the tires on a two wheel drive car, the drive wheels go straight to the next position while the non-drive wheels criss-cross to the opposite side. IOW: On your FWD Honda the R/F tire would go 'straight' to the R/R positoin, the L/F tire would go 'straight' to the L/R position. While the R/R would cross over to the L/F and the L/R would cross over to the R/F. This is the pattern that I learned from the Dodge Maintenance Manuals from my time spent working at the Dodge dealerships from 1991-1994. So, it's a bit old, but I have no reason to believe anything has changed.


*Of course, this doesn't apply to the L337 drivers who visit the AT:G! We don't have 'average' drivers here!!

 

[phucheneh]

Disclaimer: Please don't yell at me about what is 'technically proper.' I am merely stating my experience and opinion, which I feel is based in common sense. Some of you know what's coming.

...down here in Tennessee, it is pretty universal to do 'best on front.' There was a long debate about this awhile ago in which I fought most of ATG on this opinion.

I have backed off of being so adamant on that stance, but still have to say that I still have a certain amount of 'agree to disagree,' though I acknowledge the points made by my opposition. My most basic sticking point: if you are dead set on driving on two tires that are garbage, I would say, for your sake and that of other drivers...put them on the back. The OP does not fall into this category; I'm talking about tires that have almost or entirely NO tread on them, or are otherwise a safety concern. I am not saying the car will handle better, I am not saying I recommend driving such a vehicle at all. Simply saying it will be 'less unsafe.'

Unfortunately (this is why the 'disclaimer' bit...), this stance kind of extends to the OP's situation; but there are multiple ways to look at it. If you have, say, 3/32 on one axle and 5/32 on the other, I do not feel that the difference in handling characteristics between 'best on front' and 'best on rear' is that awfully significant and I am such a stubborn asshole that I would still say to put the 5/32 tires on the front. Sorry guys. Not trying to incite a riot. I mentioned my location above because we do not generally have winter weather...we have lots of rain. If concerned about slick roads, I'd say 'best on rear.' That's a big concession for me. But from a pure standpoint of channeling water, I want as much tread as I can get up front.

The OP's situation is more just a question of 'will more tread on one side do anything negative on my FWD car.' Answer- almost always no. Within reason. One concern, ABS/EST, is pretty much nil. They have to program some leeway into it, and if it was going to cause issues, it would happen with ANY kind of uneven tread situation; not just when it's split between the front tires. The other, trans damage, will definitely not be a concern given that the OP's car has an open diff and he does (I assume) at least have tires with a matching brand/model and size. Those few 32nds are not that huge, and depending on where the tire has the most tread and how he measured, the practical difference in rolling diameter may be even less.

For maximum tire life, I would rotate. Most manufacturers don't advise crossing at all anymore, but I don't disagree that crossing the tires going to the rear is typically a good idea to get the wear as even as possible. I'll also do straight crossovers in the case of staggered tires (which is why I tell people with staggered tires to never buy directionals).

If the matched tires are really THAT close (within 1/32") to lesser tire in the unmatched pair, there is no practical reason for an argument here. That 1/32" is not going to save you from needing a whole set at around the same time.

 

[deadken]

.. he does (I assume) at least have tires with a matching brand/model and size....

He did state that they are all of the same brand and model (Michelin Energy MXV4). It makes sense that they'd all be the same size.

I won't disagree with you. I've always contended that if you can steer the front, it doesn't matter too much what the rear is doing. Of course, it matters quite a bit if you aren't an experienced driver or when you don't have a lot of room to allow you to correct. So, while I also prefer the most meat on the front, I completely understand why someone who could be held responsible (the shop that installed the new tires) would want to put them on the rear of the car.

 

[_Rick_]

Unless you launch hard in an RWD car, front tires should see more wear, as they see more use during braking (through again, the rears may lock up) and steering, both of which has higher forces going through the tire than rear wheel braking and most acceleration.
With FWD it's even clearer. Fronts will see more wear, so put your good tires there.

Tread really only matters in the wet anyway, so to swap around to equalize wear is the first consideration, handling isn't really impacted until you actually start aquaplaning.

If you have low tread on the rears, you've got to be careful with torquing them up while still carrying a sideways momentum, when in wet conditions. That's about it.

In Germany (only place I know the exact value for) tread wear under 4mm remaining tread is not road legal. This is (microscopically) more than the 5/32 you still have, so I would get new tires ASAP, unless the tire has very good water displacement characteristics.

 

[kitatech]

RE Rick:
A big reason I get heavily discounted "pull-off" tires (or the odd tire) with little tread wear (8-9/32 out of 11/32 @ $50%) so I don't have to wait til they get to the wear bars to get the pro-rated replacement (NO tires last their "expected" mileage here in Florida).... by the time they get near 5/32 they can spin in Florida rain...

I get the "pro-rated" refund at the front end and can replace them "early"...

 

[monkeydelmagico]

It's fine. The tolerances aren't that tight. Hell the crown on the roadways is probably more than that.