I have a 2017 focus Titanium petrol and am really surprised that the petrol cap doesn’t lock. It opens from the outside with no locking mechanism welcoming any passer by who wants to steal my fuel.

The neck is a "non syphonable" valve

If someone really wants to steal your fuel, they'll drill the tank anyway.

Does the fuel lid not lock with the central locking, or is that just a feature on my 2005 MK2?

4 minutes ago, StephenFord said:

Does the fuel lid not lock with the central locking, or is that just a feature on my 2005 MK2?

No, since Ford introduced easy fuel, it just has anti-syphon, no locking.

Ah so it’s anti syphon. Well I never knew that. Drilling the tank? Not sure how that would work!
Anyway thanks for solving the mystery. Even my garage didn’t know the answer!

Just now, Jonathon1 said:

Drilling the tank? Not sure how that would work!

You use a 'Drill' and make a hole in the tank, put container under tank to catch the fuel 🤣

Don’t drills sometimes produce sparks which could result in more than a thief bargained for?

11 minutes ago, Jonathon1 said:

Don’t drills sometimes produce sparks which could result in more than a thief bargained for?

No, the tanks are only plastic.

Must be posh thieves using drills.  All you need is an old screwdriver and a lump hammer.

7 minutes ago, alexp999 said:

No, the tanks are only plastic.

Could still happen, apparently😀

https://www.thedrive.com/news/watch-a-tech-drill-into-a-full-gas-tank-and-start-a-massive-fire

 

2 minutes ago, TomsFocus said:

Must be posh thieves using drills.  All you need is an old screwdriver and a lump hammer.

Probably safer!😀

The first comment on that video is really odd. "I drill my own holes in my gas tank .." who on earth is drilling holes in their gas tank! 🤣

6 hours ago, alexp999 said:

No, since Ford introduced easy fuel, it just has anti-syphon, no locking.

but does that not mean we can all contaminate the fuel on anybody's late model focus - that would be ridiculous if possible

9 minutes ago, Botus said:

but does that not mean we can all contaminate the fuel on anybody's late model focus - that would be ridiculous if possible

Only if you also carry around the “shewee”. There is a valve where the locking cap used to be which prevents mis fuelling by requiring the correct diameter nozzle. So nothing can be poured in without the emergency funnel which opens the valve. 

I'm always ready to criticise new innovations, but having had this on several Fords over the last dozen years or so, I think it's great and have never had an issue. My wife's car has a conventional locking petrol cap which now seems a complete PITA in comparison. (Odd how it always seems to need fuel when I drive it, too!😀)

On 3/14/2024 at 10:09 AM, Jonathon1 said:

I have a 2017 focus Titanium petrol and am really surprised that the petrol cap doesn’t lock. It opens from the outside with no locking mechanism welcoming any passer by who wants to steal my fuel.

There are some locks available in the internet like that https://www.petrolcaps.co.uk/ford/ford-focus-locking-fuel-cap.php

. Need to be sure if/how it fits.

3 hours ago, Bol said:

There some locks available in the internet like that https://www.petrolcaps.co.uk/ford/ford-focus-locking-fuel-cap.php

. Need to be sure if/how it fits.

Sadly, as stated on that linked web site, "Warning » This item is NOT suitable for Capless / Ford Easy-Fuel Systems..."

Which is what the OP suggested he has...