AWD & Tire Tread Concern

[Gloxin]

Hello forum, I have somewhat of a concern with a purchase that I am about to make at my Ford dealership. I want to buy a 2020 Explorer ST with the Street Pack which comes with 21" wheels and I noticed on the 150 Point Inpection sheet it shows the current tire tread depth which is 7/32 for the rear and 10/32 for the front. They are all 4 Pirelli Scorpion Zero 110V M+S 275/45 R21 tires and when I asked them why do the front have different depths then the rear their response was that the two in the front are new and the rear still have more than 50% left. So now my question is: can my Drivetrain System or Intelligent 4WD get damaged if I drive it like this ?

I know that the ST is now RWD Bias which only turns AWD when necessary but still, should I ask them to put two new ones in the rear ? I just do not want to have to spend $600+ on two Pirelli Scorpion Zero tires, asumming that they are even needed. What do you guys think ?

Here is a picture showing the front and rear tread:

 

[peterk9]

Not knowing for sure, I did some checking. I'm sure others will weigh in.

"Per Tire Rack, a tread depth difference of between 2/32 and 4/32 between the tires is acceptable on AWD vehicles. So if fronts are currently 6/32, the new rears just need to be less than around 10/32."

current tire tread depth which is 7/32 for the rear and 10/32 for the front okay for AWD - Google Search

Peter

 

[J_C]

Buying something that new, I would either insist that they put two new on, or discount the vehicle to offset your doing it, or if push comes to shove, take the new tire/wheels to a tire shop that will shave them down to the same size, then wait those out to wear down too low before replacing all 4, or buy two new yourself, but are the "new" tires really new? It could be useful to know what the mileage difference was when they were put on.

As-is, it won't necessarily cause immediate damage but is not ideal for the long term. It will cause more than zero extra wear. I wouldn't risk it for a newer vehicle worth a good amount of money.

 

[Gloxin]

Buying something that new, I would either insist that they put two new on, or discount the vehicle to offset your doing it, or if push comes to shove, take the new tire/wheels to a tire shop that will shave them down to the same size, then wait those out to wear down too low before replacing all 4, or buy two new yourself, but are the "new" tires really new? It could be useful to know what the mileage difference was when they were put on.

As-is, it won't necessarily cause immediate damage but is not ideal for the long term. It will cause more than zero extra wear. I wouldn't risk it for a newer vehicle worth a good amount of money.

Thanks for your reply. I just found this on the Explorer ST Manual. Seems that I will be fine. I'll still ask them to put two more new ones if possible but since the old ones have more than 50% life left, I doubt they would do that.

 

[J_C]

I'd still do one of the options I mentioned. Whether it "can" compensate or not, either way something has to slip more, constantly, even in a straight line, than if they were all the same diameter. I take that back, if the same axle has the same size on both sides, it could disengage the driveshaft to that differential, but it's still the times it is engaging that I'd be concerned about.

 

[CDW6212R]

That's a large difference in tire diameter, it indicates that the tires were not rotated properly. I would discuss that with them, make it clear that the problem exists and the prior owners are at fault.

Decide what to do about the miss matched tires, I don't let my tires get that far differently worn down. You should figure out which end wears out faster, the front tires or the rear. The better tires should go on the end which wears them faster, plus you have to keep an eye on them regularly.

The later "AWD" systems don't use a viscous clutch like the early versions did, the new stuff are not AWD, they run 2WD until the front-rear speed is different enough, then it engages a clutch inside the transfer case. The late 90's Fords began that, they called it A4WD(Control Trac), which was an accurate name. You could make the rear tire spin briefly before the transfer case would engage the front drive shaft, then it was in 4WD until the spinning stopped. That was only for a second, but it was automatic 4WD.

Now the systems are faster and don't noticeably present any tire spin before it engages the other drive shaft. It's better, but it's not 4WD, it's automatic, or by choice selected 4WD. In all cases it is not AWD, which is 100% all tires driven all the time.

 

[dvdswan]

Was it a prior lease vehicle? Or owned? How many miles? The lower the miles, the more the PO hot rodded the ST.

 

[Gloxin]

Was it a prior lease vehicle? Or owned? How many miles? The lower the miles, the more the PO hot rodded the ST.

It was a leased vehicle from 2020, one owner and it currently has 22,378 miles on it.

 

[Dale5403]

I get my tires rotated every oil change. Keeps the wear very even. Best case for you if they would replace the rear tires. Good luck.

 

[HacksawMark]

From the pictures above, the rears look much more worn than what they're telling you. I would go buy a tire depth gauge (they are cheap) and check it yourself. I would bet they are not 7/32". More like 4-5/32". It could be the angle of the photo but the center of the tires look worn as if they were driven overinflated.

 

[GeoTracker]

Are the tires marked PNCS? I had to replace all 4 at 25K due to vibration issues caused by loose foam inside the tires. Known problem in hot climates. Really bad to road speeds around 65-70 MPH.

 

[Gloxin]

Are the tires marked PNCS? I had to replace all 4 at 25K due to vibration issues caused by loose foam inside the tires. Known problem in hot climates. Really bad to road speeds around 65-70 MPH.

They are not marked PNCS. I only see 275/45 R21 110W M+S A087224

 

[GeoTracker]

They are not marked PNCS. I only see 275/45 R21 110W M+S A087224

They must have put two different type of tires on the Street Pack. Mine were marked "PNCS" under the "ZERO" marking. If not that is a good thing for you. Unless that had already been replaced.

 

[Gloxin]

From the pictures above, the rears look much more worn than what they're telling you. I would go buy a tire depth gauge (they are cheap) and check it yourself. I would bet they are not 7/32". More like 4-5/32". It could be the angle of the photo but the center of the tires look worn as if they were driven overinflated.

You were right, I went down there and measured them myself and the front has 10/32 and the rear has 4/32 - 5/32. But they do not want to change them because they say that it still has life left. I am thinking of just backing off from this deal and wait it off for now.

 

[peterk9]

You were right, I went down there and measured them myself and the front has 10/32 and the rear has 4/32 - 5/32. But they do not want to change them because they say that it still has life left. I am thinking of just backing off from this deal and wait it off for now.

While they do have some tread life left (2/32" is considered bald), you will always be in this situation as long as you own the vehicle unless you change all 4 at some point in time. Have you tried to talk with them about a discount on 2 new tires?

Peter

 

[Gloxin]

While they do have some tread life left (2/32" is considered bald), you will always be in this situation as long as you own the vehicle unless you change all 4 at some point in time. Have you tried to talk with them about a discount on 2 new tires?

Peter

I did and they said NO. I also asked them if they can redo the 150 Point Inspection just to make sure there isn't any other inaccurate information in there since they got the tire tread wrong I have every right to have doubts now and they also denied that request. I also found out that they replaced the two turbos 3 weeks ago and the vehicle only has around 22,000 miles on it.

 

[peterk9]

I did and they said NO. I also asked them if they can redo the 150 Point Inspection just to make sure there isn't any other inaccurate information in there since they got the tire tread wrong I have every right to have doubts now and they also denied that request. I also found out that they replaced the two turbos 3 weeks ago and the vehicle only has around 22,000 miles on it.

If you can find a comparable vehicle elsewhere, I would walk away from this one. I'm guessing that the rear tires are likely the original ones begging the question as to why the fronts had to be replaced.

Peter

 

[HacksawMark]

I did and they said NO. I also asked them if they can redo the 150 Point Inspection just to make sure there isn't any other inaccurate information in there since they got the tire tread wrong I have every right to have doubts now and they also denied that request. I also found out that they replaced the two turbos 3 weeks ago and the vehicle only has around 22,000 miles on it.

Unbelievable that it's from a Ford Dealer. Personally, unless they either didn't change out the tires or come down in price by $500, I would continue my search elsewhere. But also keep an eye on this one. The longer it sits on the lot, the more likely the price will come down.