Hi. I have noticed that some Focus and Kuga models have 5 nuts per wheel, while others have 4. It seems to be the older models that have the extra nut. Do you know the reason? Is it heavier diesels that have 5 nuts? Or are the ecoboost cars lighter and there has been s move to 4 nuts? Thanks.

It tends to be the same for all vehicles from one model of that generation. I’ve never seen it differ just for different engines. 
 

It’s generally down to weight. Kuga and focus are heavier. Fiesta is lighter. Older focus that used to have 4 is also lighter than models since mk2. 

My 16 year old Mk2 Focus has 5 x wheel nuts, on proper steel wheels!

Do any cars still have 3 nuts? Like Renault 4 and mk1 Renault 5 and I think maybe talbot samba also

 

38 minutes ago, isetta said:

Do any cars still have 3 nuts? Like Renault 4 and mk1 Renault 5 and I think maybe talbot samba also

 

Crikey, I remember servicing samba and the Peugeot  with 3 wheel nuts with oval washers. You didn't gun them up as the washers may not sit correctly then wheel could fall off a while later. 

Some 106 & Saxo were 3 stud in the late 90's.

Renault Twizy and Smart cars are still using 3 stud I think...but it's debatable whether those are really cars.