I recently had alloy wheels fitted to replace the factory steel wheels.

I still have a full size steel spare wheel in the boot. Am I correct that the alloy wheel nuts are not compatible with steel wheels?

I kept the steel wheels, trims and wheel nuts after the alloys were fitted.

I will keep 5 of the steel wheel nuts in the boot in case I ever have to fit the steel spare.

Did cars that had alloys and a steel spare from new come supplied with separate nuts for the steel spare?

Someone on here will answer more accurately but I believe you can get corrosion by using dissimilar metals, aluminium and steel being two that don't work well together

The tapper of the the nuts used on the alloy wheels is different to a regular steel wheel on vehicles manufactured before 2013 so you will need to keep the original nuts for use with the steel wheel.

Cars that came with factory fitted alloy wheels either had a full size alloy wheel as a spare. or they came with a space saver steel wheel. These temporary wheels are designed to use the same nuts as the alloy wheel so they don't use different nuts.

See the post below by JW1982 which shows the different types of lug nut.

On 12/3/2020 at 6:32 AM, JW1982 said:

It is very important to select the correct type of wheel nuts.

A few years ago Ford decided to standardize the (technical) design of the wheels and wheel nuts to a global Ford standard. In technical documentation these new type of wheels and wheel nuts are called Global wheels and Global wheel nuts. Nowadays the Global wheels and wheel nuts are used on most different Ford models around the word. 

Early Focus MK3 models (produced before 11-05-2012) did have the new type global Wheels combined with the old design 1-piece (solid) wheel nuts. However this combination does not fit to most other Ford models.

Original Ford wheels can be identified by the size of the wheel nut holes:

Old design Alloy wheel  VS  global wheel.

 

The original wheel nuts can be identified by the following pictures:

Old design wheel nuts:

Left = Wheel nut for steel wheel.
Mid = Wheel nut for alloy wheel
Right = Locking wheel nut for alloy wheel.

 

Global wheel nuts:

Left = Global wheel nut for steel wheel.
Mid = Global wheel nut for alloy wheel
Right = Global locking wheel nut for alloy wheel.

 

On a Focus MK3 with original (global) wheels both of these wheel nut designs can be used. It is however very important not to mix the different wheel nut designs and use the correct tightening torque.

 

IMPORTANT!

IMPORTANT!

Original old 2-piece design wheel nuts as shown on the picture above can not be used on global wheels. Insufficient contact between the wheel nut and the global wheel will cause the wheel nuts to come loose!

 

Thanks for the reply. All the nuts used with the alloys are the old two piece type with the rotating collar.

I saw the post with the photos before I got the nuts from the breakers as the alloys didn't come with nuts.

I see that the global wheel nuts have a rounded top so are easy to tell apart at a glance.

I am considering getting one of the 5 spoke steel wheels and painting it silver for keeping as a spare. That way it isn't so obvious at a glance against the 5 spoke alloys if I need to use it.

Do they use the alloy wheel nuts? I am sure all I have seen on cars had the alloy nuts fitted.