Mismatched car tyres - what would you do?

Triangle tyres have terrible reviews

People actually read tyre reviews?! Jeez.

It does on my car, from experience.

I can’t imagine how you have to drive to have this problem.

People actually read tyre reviews?! Jeez.

How do you choose new tyres?

Er..I just buy new versions of what is already on there.

I can honestly say I've never noticed any difference in my car tyres, apart from road noise. Obviously I'm not a driving expert.

No question I was being a dick when that happened. It was however under hard acceleration on a corner in a RWD car. The problem wasn't a slide caused by mis-matched tyres. I can't imagine how you would have to drive to accidentally slide during a corner specifically because your tyres were mismatched, which was the original post.

I can honestly say I’ve never noticed any difference in my car tyres, apart from road noise. Obviously I’m not a driving expert.

It happens when you have to do an emergency stop. Good tyres stop you much quicker than bad ones, again from experience. And I have had cars that would easily wheelspin trying to pull out onto a roundabout on the OEM tyres, and the problem went away when I bought decent ones.

Er..I just buy new versions of what is already on there.

I can honestly say I’ve never noticed any difference in my car tyres, apart from road noise.

I wonder why that could be.

I wonder why that could be

Do tell, please

Well I'm glad we are now understanding that there are external factors that might lead to unintended or unplanned cornering taking place.

Ha! I just bought a car with exactly the same problem except instead of the Nexens on the front it's another pair of triangles. After 3k miles I can say they are right up there with Intensa Savas as the absolute worst shit I have ever driven with.

During the recent snow in Sheffield I was taking it super easy, approaching a roundabout at no more than walking pace, braked, and glided on uninterrupted straight into the path of an incoming pickup which, thankfully, I managed to accelerate away from. That's never happened to me on Maxxis, Michelin, Kumho, Nexen, Vredstein, Nokian or any other brands I've used all season or winter tyres on.

They're utter crap in the wet as well. Costco will be getting a visit.

Well I’m glad we are now understanding that there are external factors that might lead to unintended or unplanned cornering taking place.

Do you have any other conversation mode besides sarcasm?

It does more than that, it will also take over steering.

It’s there to prevent a spin or a slide from what I can tell.

Sure, it will regain stability when one axle has lost friction which means a yaw movement, either understeer or oversteer. It does that through braking an individual wheel as I said.

So you're right it does steer the car by an effective transfer of friction.

Which is perhaps what you experienced rather than the steering rack being activated without your steering input. But perhaps your car does have active steering, what car is it?

To answer the question, I would replace all with a premium tyre.
Alternatively, lose the mismatched pair and replace with Nexens which will then give you a full matching set.
Don't forget the spare - if it's full sized; if it's a crappy space saver, who cares.
Pays your money and all that stuff.

Saccades
Free Member

Which is grand if you like to “make progress” and are a great driver, let’s just hope the experiment doesn’t go wrong when you least expect it to.

Nah, that's kind of my point- you do the experiment/testing/practice in the safest conditions you can, so that you don't find things out at the worst possible time. It's like absolutely anything else, practice and preparation and repetition are good things. Go out and do that emergency stop in the rain- when was the last time you did a really full beans hard stop? Improve skills and experience and knowledge of the car, bank some muscle memory and some lizard brain reactions, and try to find issues in a safer situation. Sure, there's still risks involved but a small risk today can pay off later.

I might still panic, I will sometimes get it wrong, at the end of the day I'm just a normal competent-enough driver not a Driving God but you can do a bit to stack the odds in your favour, both in hardware and software. This thread was pretty much about hardware but they're inseperable really.

Hopefully I'm the opposite of a STW Driving God!

But perhaps your car does have active steering, what car is it?

That's the Mercedes. It has electric power steering, with a motor on the steering rack. The Prius also had such a motor, because it had a self parking feature, but I never felt it activate during ESP operation. Pretty sure the Passat did too, but the same applies. Perhaps it never activated because they were both FWD. The Hyundai also tugs the steering wheel but only when drifting out of lane, I don't know if it would when sliding. But again, it's FWD.

The woman who I saw crashing her Fiat 500 said that the steering 'locked up' and she couldn't turn the wheel enough. I can't be sure, of course, but I think this was because the ESP was preventing her from steering too much and losing front wheel grip.

I can’t imagine how you would have to drive to accidentally slide during a corner specifically because your tyres were mismatched, which was the original post.

The pool car from work I had with mismatched tyres would handle differently on rights and lefts despite tracking straight and Also did not want to go straight under hard braking braking in the wet.  It was borderline dangerous and certainly it was compromised and had lower safety margins.

I can’t imagine how you would have to drive to accidentally slide during a corner specifically because your tyres were mismatched, which was the original post.

Emergency lane change in the wet on the motorway. All the anticipation in the world can't account for every random event, but appropriate tyres can mitigate the effect.

SO, in the unlikely event anyone wants to know the outcome to this...
After far to much time in a hole of tyre reviews and other such stuff I am booked in to replace both back tyres as the PilotSport was starting to crack a bit. 2 new Bridgestone's will be going on as they score well for both wet braking and fuel economy.
Unless told otherwise, the Nexen's will stay on the front until they wear out and the new tyres will go on the back.

Front 2 are Nexen’s, both brand new, not a brand I’d choose but they get OK reviews.
At the back there is a Michelin Pilot Sport on one side and a Triangle SporteX on the other. Both have lots of life left in them.

Has the OP reappeared yet? Hopefully they've not gone backwards through a hedge in a ball of fire due to mismatched tyres? FWIW, I'd do what someone already mentioned and replace the single Triangle tyre with another Michelin PS, or replace the Triangle and Michelin with two other matching tyres. Problem isn't the Michelin, or with the Triangle, but with there being mismatched tyre characteristics on the same axle.

Car I've just bought - an 8yr old MINI - came with two Dunlop Sport Maxx RFTs on the rear and two Sailun Atrezzo ZSRs on the front, all excellent tread depth. I knew about the Sailuns before buying and expected I'd immediately want to swap them out. After driving the car about 300 miles now, I might! Rated 'C' for wet grip - coincidentally the same wet grip rating as the Triangles mentioned by the OP. When buying tyres I never go for less than A-rated. I've felt worse tyres in the past and they're not absolutely terrible, but I'm not a driving god and can definitely notice the difference with these*

* yes, it's a new-to-me car but I've driven a similar MINI extensively before with excellent tyres so have a comparator.

EDIT: @lunge's reply appeared after I've typed mine out! Glad you're still here - good choice of action.

It might give the impression it is due to how it’s applying brakes/transferring power causing you to need to apply more force to the steering wheel, but it won’t take over steering.

"Take over" is pushing it. But stability does stiffen up the power steering (to minimise kickback from kerb strikes etc) and changes the bias (L/R) to encourage you to steer in the right direction. Gives a subtle pull one way or the other if activated in isolation. Hands off the wheel, it'll start to steer gently. When combined with the brake distribution it can give a quite noticeable steering effect. I've had it on 3 or 4 cars now, going back 7 or 8 years. And driven/tested dozens. Loads of manufacturers use it in one form or another.

Actual active steering intervention is coming, some manufacturers may already have it in production in level 2 autonomous driving (adaptive cruise with lane centring) and advanced collision avoidance systems. Issue being that the car usually doesn't have enough information or processing power to work out which way to steer safely to A) maintain stability/straighten up and B) avoid what you're about to hit, at the same time. As they are sometimes the opposite direction.

In my case it didn't 'take over steering' it just yanked the wheel which to me makes perfect sense. It knew I was hard on the accelerator and holding a left hand line, so the lateral sensors would have measured my cornering speed. So when the lateral acceleration suddenly decreased it knew what was happening so backed off the throttle, and just twitched the wheel, I am pretty sure. May not have, but I reckon that's well within the capability of such a system. In any case it was very effective and didn't even interrupt my acceleration. I backed right off though, since I realised how bad of an accident it would have been if the ESP hadn't worked. Lesson learned about RWD cars.

In my case it didn’t ‘take over steering’ it just yanked the wheel which to me makes perfect sense.

So it was almost certainly the brakes then. Or at least, one front caliper correcting your path.

Ok, fair point.

Presumably then as I was going round a left hand bend and it knew the rear had slipped, it touched the front right brake and possible both rears?

Quite possibly. But the finer details will be in Mercedes software, which i don't have access to. Unsurprisingly.

And to take it back to the OP, all these traction and braking interventions are dependent on the car having broadly equal curves for lateral and longitudinal grip on each axle.

I was wondering this - I assume it has to be responsive to the actual situation of each tyre, rather than predictive based on the tyre characteristics?

I mean you might have four identical tyres but if one is on mud then it has to cater for different levels of grip there and then, surely, otherwise it's not much use? And having one tyre on mud or diesel must be equivalent to having one worse tyre?

Modern ESPs and ABS systems have ability to keep that straight car during braking even if other side is on ice and other side on dry tarmac. This will affect on stopping distance but the other option is often worse. And by modern I mean post 2000 vehicles, I remember reading some Renault having issues with this in late 90's when most cars had no problem with this.