285 Tread Width Tires (anyone else have radial-like pull?)

[traumkommode]

I wanted to bring this up because I was surprised that using such a marginally narrower tire would cause such significant pull. Maybe worth a sticky if other people pipe up with the same issue.

I bought my 2020 GT350 last fall in Kansas City, where it gets very cold. The car is my daily driver, so I put all-seasons on my cars in the winter so I don't loose grip. I've felt what that's like and it's not fun. I was running Michelin Pilot Sport All Season 4 tires in 285 section width - common size alternative that I've seen people using for an all-season in this model for winter driving. I read no other reports about the tires causing a radial pull. I discussed it with the folks at Discount Tire and they thought it was not enough of a size difference from stock to cause an issue.

I even had Discount Tire try an entirely different set of these tires, and we swapped side to side to rule out radial pull from a bad tire mold, and it still pulled left. After over a month at a very fine Ford dealership service center, and their trying everything all the way down to tweaking the subframe, they finally got ahold of a set of wheels and tires that matched the factory width, and low and behold the 285 tires were what was causing the car to walk across lanes. I'm going to chalk it up to the steering/handling/suspension on the car being engineered so precisely that the tires just didn't have enough grip to make the car happy.

Has anyone else experienced this? Not that I'm anyone of any kind of sway, but I'm going to call Michelin and put in a request to their feedback team to make the PS AS 4 in at least 295, because I do want to continue to drive the car when it's cold. I live in Asheville in the mountains now and snow is only very occasionally an issue, just colder weather during winter. When I bought the car it was on a square 295 snow tire setup, I think they were Blizzaks but I could be wrong about that. But they lost all of their grip as soon as it started raining. I'm talking they made the Sport Cup 2s look like wet grip champions, and they still had significant tread on them.

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[2019GT]

For what its worth, I'm on the AS4 as well but 275/35/20 and 315/35/20 and that squirrely feeling is gone when driving in cold weather.

Whether it's taking corners relatively hard (tire screech) or doing straight line pulls, these tires handle 700whp pretty damn good for my limited experience lol.

It's probably the stagger more than anything that helps, because I was running a square setup of 275/40/19 in the AS4 and I didn't like it. The car felt too jittery for my liking

 

[traumkommode]

For what its worth, I'm on the AS4 as well but 275/35/20 and 315/35/20 and that squirrely feeling is gone when driving in cold weather.

Whether it's taking corners relatively hard (tire screech) or doing straight line pulls, these tires handle 700whp pretty damn good for my limited experience lol.

It's probably the stagger more than anything that helps, because I was running a square setup of 275/40/19 in the AS4 and I didn't like it. The car felt too jittery for my liking

This is a great point, I had wondered if the pull was actually coming from the rear. I could try a wider rear next winter. Thanks for chiming in, this is the kind of thing that makes me love the forums.

 

[2019GT]

This is a great point, I had wondered if the pull was actually coming from the rear. I could try a wider rear next winter. Thanks for chiming in, this is the kind of thing that makes me love the forums.

Of course man, check out this thread I made a few months ago. I was in the same situation actually. It almost made me not want to drive my car: https://www.mustang6g.com/forums/th...handle-roll-racing.192091/page-3#post-3887420

That thread's mostly about highway pulls, but I had that squirrely feeling just in general. Not like I was actually gonna get sideways, but stability just felt off even with an alignment and balance.

The big takeaway is I went up in size from a 19 to 20, and widened the rear out to 315. Effectively steepened my gearing with a stagger for a compounding effect on straight line and cornering stuff lol.

Next winter should go a lot better!

 

[JAJ]

This is a great point, I had wondered if the pull was actually coming from the rear. I could try a wider rear next winter. Thanks for chiming in, this is the kind of thing that makes me love the forums.

I'm running all-season 255/40x19 fronts and 275/40x19 rears mounted on 19x9.5 2014 GT500 rims on my GT350 and the car drives fine. Something else is out of whack, probably wheel alignment. Did you get an alignment check done? The car will handle really strangely if the back end is out of spec.

 

[robvas]

Just priced out those AS4's, holy crap

 

[Hack]

SNIP radial pull SNIP

I've never heard that term before. Seems like it's trying to blame the tires for something.

I'm not sure, but I think you are talking about tramlining, where the car wants to follow indents in the road. When the road isn't very flat, the car pulls in one direction or another.

This is a characteristic of the GT350. You can dial it down with alignment settings. I don't remember the specifics, but there are plenty of threads on it if you do a search.

I call it "steering feel". The GT350 steering isn't numb, where all road information is blocked out. I realize it's uncommon in modern cars. My cheap Camaro exhibits this symptom as well. Not as much as the GT350, but it also has much narrower tires.

What I did about this issue when I was driving a GT350 was - nothing. I just continued to drive the car and I got used to it. I think if you relax behind the wheel a little that helps.

 

[2019GT]

Just priced out those AS4's, holy crap

They absolutely suck in the snow, if that gives you an idea how "all season" they really are lol. They're basically a summer tire that you can enjoy the hell out of in below freezing temps. They were so worth the money to me lol. And they're incredible in the rain.

 

[NightmareMoon]

So all 4 tires are the same type and sizes (left/right), and its pulling consistently left? And you had the alignment checked and that’s fine? And the problem seems to be reduced by changing the width/size of tire?

When I had a problem like that we eventually tracked it down to a bearing on a control arm which had developed some play, but it was pretty hard to find. The cues are the alignment is off at speed (pulls left) but looks fine on an alignment rack. Which indicates something is shifting under road force. Tire width wont cause that type of issue, but some tires can probably mask the issue to a degree.

 

[traumkommode]

I'm running all-season 255/40x19 fronts and 275/40x19 rears mounted on 19x9.5 2014 GT500 rims on my GT350 and the car drives fine. Something else is out of whack, probably wheel alignment. Did you get an alignment check done? The car will handle really strangely if the back end is out of spec.

Yes, had several alignments done, subframe examined, had a strut replaced that they said looked slightly off. Tried a whole other set of tires.

I've never heard that term before. Seems like it's trying to blame the tires for something.

I'm not sure, but I think you are talking about tramlining, where the car wants to follow indents in the road. When the road isn't very flat, the car pulls in one direction or another.

This is a characteristic of the GT350. You can dial it down with alignment settings. I don't remember the specifics, but there are plenty of threads on it if you do a search.

I call it "steering feel". The GT350 steering isn't numb, where all road information is blocked out. I realize it's uncommon in modern cars. My cheap Camaro exhibits this symptom as well. Not as much as the GT350, but it also has much narrower tires.

What I did about this issue when I was driving a GT350 was - nothing. I just continued to drive the car and I got used to it. I think if you relax behind the wheel a little that helps.

The car tramlines now with the stock tires on, and I'm familiar with that having driven a PP2 GT previously that came with 305 Cup 2s all the way around. I like the tramlining, it feels appropriate for the car. But what I was experiencing was not tramlining, it was consistent pull to the left like the alignment was off, but it wasn't.

They absolutely suck in the snow, if that gives you an idea how "all season" they really are lol. They're basically a summer tire that you can enjoy the hell out of in below freezing temps. They were so worth the money to me lol. And they're incredible in the rain.

I've never actually driven them in heavy heavy snow. I've driven them in very cold and in light snow and they always did fine for me on several vehicles. I moved back to Western NC where the twisties are glorious and we rarely get much snow, so it's just longer-term cold that I've gotta watch out for.

So all 4 tires are the same type and sizes (left/right), and its pulling consistently left? And you had the alignment checked and that’s fine? And the problem seems to be reduced by changing the width/size of tire?

When I had a problem like that we eventually tracked it down to a bearing on a control arm which had developed some play, but it was pretty hard to find. The cues are the alignment is off at speed (pulls left) but looks fine on an alignment rack. Which indicates something is shifting under road force. Tire width wont cause that type of issue, but some tires can probably mask the issue to a degree.

See, I thought something like this might have been going on. But when they finally found a set of wheels/tires that were factory width to test, the pull went away. The pull I was experiencing was to the left, but it was at all speeds, not just at highway speeds. Low speeds, high speeds - constant pull. Certain road crowns it would pull in the other direction, but it needed to be significant crown. Slight crown it would actually pull itself back up the crown when pulling to the left. Now it tracks straight when its flat, will follow a crown or a rut like is normal tramlining for the stock tires.

What did they do to identify the loose control arm bearing, just visually inspect and manipulate it with their hands? Now I kinda want to call the service rep back and ask them if they looked at the control arms, although I think at this point Ford will just say they're satisfied with the tire swap.

 

[NightmareMoon]

Yes, had several alignments done, subframe examined, had a strut replaced that they said looked slightly off. Tried a whole other set of tires.



The car tramlines now with the stock tires on, and I'm familiar with that having driven a PP2 GT previously that came with 305 Cup 2s all the way around. I like the tramlining, it feels appropriate for the car. But what I was experiencing was not tramlining, it was consistent pull to the left like the alignment was off, but it wasn't.



I've never actually driven them in heavy heavy snow. I've driven them in very cold and in light snow and they always did fine for me on several vehicles. I moved back to Western NC where the twisties are glorious and we rarely get much snow, so it's just longer-term cold that I've gotta watch out for.



See, I thought something like this might have been going on. But when they finally found a set of wheels/tires that were factory width to test, the pull went away. The pull I was experiencing was to the left, but it was at all speeds, not just at highway speeds. Low speeds, high speeds - constant pull. Certain road crowns it would pull in the other direction, but it needed to be significant crown. Slight crown it would actually pull itself back up the crown when pulling to the left. Now it tracks straight when its flat, will follow a crown or a rut like is normal tramlining for the stock tires.

What did they do to identify the loose control arm bearing, just visually inspect and manipulate it with their hands? Now I kinda want to call the service rep back and ask them if they looked at the control arms, although I think at this point Ford will just say they're satisfied with the tire swap.

After aligning it and driving it over and over and always having some pull to one side (at all speeds) and me not letting it go and, the alignment tech finall noticed some play at one wheel.. you could push and pull on the tire/wheel and see some movement. Ah hah!

So If you jack up each wheel and then try to manhandle each wheel and tire, if you find anything that can be shifted a mm or two, you might have found your issue.

 

[Hack]

The car tramlines now with the stock tires on, and I'm familiar with that having driven a PP2 GT previously that came with 305 Cup 2s all the way around. I like the tramlining, it feels appropriate for the car. But what I was experiencing was not tramlining, it was consistent pull to the left like the alignment was off, but it wasn't.

Ahh, gotcha. Sorry about my misunderstanding.

If you can swap tires and it still pulls left there's a suspension issue the alignment shop is missing. Or they out and out measured the alignment incorrectly. My opinion is they must be overlooking something.

 

[MD18EcoStang]

I just can't imagine how 10mm of tire width could cause or solve a problem such as this.

 

[traumkommode]

After aligning it and driving it over and over and always having some pull to one side (at all speeds) and me not letting it go and, the alignment tech finall noticed some play at one wheel.. you could push and pull on the tire/wheel and see some movement. Ah hah!

So If you jack up each wheel and then try to manhandle each wheel and tire, if you find anything that can be shifted a mm or two, you might have found your issue.

Cool, thanks for that specificity. Randy Marion Ford Service was excellent, and even said they'd install a 1-piece driveshaft and warrant the work, which I want to have done sometime soon-ish. I'll ask them to do this then, because they're an hour and a half away, but to the points of people I quoted below, I think you might be on to something. Which direction push/pull and which direction did the wheel move? When I go back I want to be able to give them as specific a thing to look for as I can so they'll be more likely to find it if that's what it is. I really appreciate this.

Ahh, gotcha. Sorry about my misunderstanding.

If you can swap tires and it still pulls left there's a suspension issue the alignment shop is missing. Or they out and out measured the alignment incorrectly. My opinion is they must be overlooking something.

I want to agree here. See my response below.

I just can't imagine how 10mm of tire width could cause or solve a problem such as this.

So, in comparison to the Cup 2s, the PS All Season 4's, while excellent tires, feel very floaty by themselves. You can still tell the car handles great on its own, but the tires feel edit: vaguer, floaty-er, and even though they're firmly gripping, they don't feel like they're gripping that much. The steering wheel feels like it gained edit: significant weight after switching the tires in all driving modes. So I was willing to chalk it up to, "okay, maybe the EPAS and IRS are calibrated so precisely that we've reduced the frictive forces on the roll-y parts enough that the system is compensating in a way that causes drift now. I did have some moments on the All Season 4's where the EPAS felt like it would let go a little bit all of a sudden, and the steering wheel would lighten up and turn back in the opposite way all of a sudden. It's not doing that with the Cup 2s, and I feel like I can tell a lot more about how this EPAS actually behaves with these tires. It does track straight now as often as it can just due to tramlining, and it's not a "leave your hand off the wheel for a long time" kind of car nor do I expect it to be. But, everyone I talked to thought that this was too small of a difference in tire to affect it that much, just like you're saying. I'm glad

 

[NightmareMoon]

Push/pull in and out hard at different spots around the tire. The goal is to find out if any bearings or bushings are shot so you need to try a few different directions and spots because we dont know where to focus right now.

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