What is the spec and size of the factory fit tyres, web sites do get things wrong. The info should be in your handbook or on your door pillar or possibly the inside of the fuel cap.

Its perfectly OK to go for tyres with a higher speed and load rating but going lower can potentially create problems after an accident (and not just with your insurers).

For your info a Y rated tyre has a higher speed rating than a W thus you are fine in that respect but you are not OK on load rating.

A V rated tyre has a lower speed rating than a W thus you are not OK but the load rating of that tyre is fine.

My advice is to speak to your insurers first but if I was in your position I would be buying 4 new tyres top match the OEM spec.

The problem is tyre retailers, most are total idiots. Our local indy used to be well respected and still does great trade but whenever I have been in recent years he has tried to sell me tyres with lower speed and load rating than OEM and has been insistent its fine since the UK limit is 70 mph. However, when I requested he would not put down on paper that all would be OK.

One minor point, a 1.5 Focus will not do 168 mph. Lucky if it will do 120 mph.