Should a car dealer replace a tyre that doesn't match the other three?

Telegraph

2 days ago

After I bought a 14-month-old Suzuki Swift from a dealer I found three of the tyres are Bridgestone Ecopia EP 150, but the front nearside is a Lassa Greenways Extra Load item. So normal tyres and a stiff-walled tyre are mixed on the front axle, which I understand is not recommended. The dealer said that the non-matching tyre shouldn't cause any issues, that the car would pass an MOT, also that an odd tyre wouldn't usually be replaced as part of its pre-sale inspection as it wasn't a lower speed rating than that specified by the manufacturer. Do I have any recourse?
– BH
No. While not an ideal state of affairs, the car you bought is road legal and is not deemed to be unsafe. You're correct that it is not best practice to mix tyres across an axle, and as a result, my suggestion would be to replace the odd tyre (or both front tyres, if the tread depth has dropped significantly on the Bridgestone) with matching rubber.
I've bought cheap used cars that have had four different brands of tyre – and while I always got them changed, I didn't deem it something I had to take issue with the seller over.
As the dealer says, it will still pass an MOT test, while you'd have a hard time proving in a court of law that the dealer sold you a car that was not fit for purpose.
Besides, if you took the matter further, the dealer could entirely reasonably point out that you should have checked that the tyres were matching when inspecting the car before purchasing it; you could even have suggested you wanted the tyre (or tyres) replaced as part of the deal.
My advice is to replace the Lassa tyre at the earliest opportunity, chalk this one up to experience – and, the next time you buy a car, check that the tyres match.