Mixing speeds

[Archibald]

Probably a bit of an extension to the mixing groupsets, but a bit more specific.
I'm aware the differences between componentry across the various speeds - 7,8,9 v 10 v 11... but what can be interchanged?

Reason for asking is that while I ordered a 10spd FD (5700), the one that arrived in the post is 11spd (5800)...
I know that you can't mix RDs, chains and cassettes, but what about the FD? Is there any real difference between front derraileurs between speed groups?

Can I successfully use an 11spd FD on a 10spd setup?

 

[King Boonen]

I think Shimano changed both the front and rear pull ratios when they went 11 speed so... I think the answer is probably not, but I've never tried.

 

[Archibald]

contacted the seller - they confirmed that it wouldn't work, so resending the 5700. They also confirmed that they had their 5700s and 5800s mixed up in the warehouse, hence the error...