Hi all,

Please find attached an image of the underside of my Ford Fiesta 2016 petrol.

Out of interest this picture is taken for reference before the car went in for underseal treatment.

I'm interested today to learn about components on the underside of the car.
Primarily the 4 lines running parallel on the underside.
I have highlighted them in light blue and numbered 1-4 in the additional image.

Bonus: Is there a specific name for the cross bar I have highlighted in blue-gray?
Bonus 2: Is there a specific name for the 2 support bars I have highlighted in gray?
 

Let me how the image quality is on the attached image if unsuitable.

Thanks for your time!

 

They'll be the fuel and brake lines.

For the rest of your query, go on www.catcar.info, select Ford and look to see if your model is there, or put in your vin and browse the results. It contains parts diagrams with part numbers, tho' isnt upto date with the latest models. If you can't see your model there, look at the next most recent one, it might be similar. 

The two thin pipes are rear brake lines.  Chances are, 1 is right brake and 2 is left brake, for most efficient use of material. 

Number 3 is the fuel feed line from the tank pump to the engine.

Number 4 you'd expect to be a fuel return line...but there isn't a return on many petrol Fords.  So I suspect that one actually goes to the charcoal cannister instead.  That absorbs petrol vapour from the tank using vacuum from the engine to prevent raw petrol evaporating into the environment.

 

The single cross bar is just called 'Cross Member Assy'.

Ford call the 2 front supports bars a 'gusset', which I've just learnt is a word not only for clothes...