Some duct tape & 10 minutes... Fiesta S quick mod.

[niky]

You know... never thought to do an A-B-A with just the foglight covers. Might be worth looking into, because, as RedDevil says... it seems they might be a means of adjusting airflow around the car (in this case, they're likely a way of kicking air away from the wheel wells.

But the biggest gain will definitely be from a grille bllock.

[2000mc]

I'm voting for losing the tape, sounds like they poked around these areas looking for aero tweeks

The new Fiesta was tested more than 150 hours in the wind tunnel to refine its aerodynamic efficiency, resulting in a 3 percent reduction in drag, further benefitting fuel efficiency and CO2 emissions. Improvements have been achieved in part through revisions to the front air-deflector design, the introduction of an enhanced rear spoiler, under body optimisation and careful configuration of light units to separate air flow and reduce the vehicle’s wake.
https://media.ford.com/content/fordm...nectivity.html

[freebeard]

As vehicles become more optimized there's less 'low hanging fruit' in terms of quick and easy gains.

The only way to make further gains is to step outside the normal use case, in terms of things like ride height and cats on spin cycle in the wheel wells.

[RedDevil]

Forgive me brothers and sisters for I have sinned against this very principle...
like this! (aero fog light cover)


Albeit that they are yet far away from the edge (at the right of the picture) so it probably does not disrupt the effect too much.
It may even be good, there is a sharp ridge at the edge of the bumper anyway.
And it does solve my main concern: protecting the fog lights from stone strikes.
The covers are curved though the photo does not show that. The curve makes the thin plastic stronger.

Then I cannot say it helped FE wise, it got worse last 2 weeks.
But I had to air up the tires a bit again and one of the brake disks is slightly warmer than it should be despite the extra pad return spring.
Too many variables, too small an effect.

[user removed]

http://ecomodder.com/forum/showthrea...sta-28032.html

Here is my cheap, stealthy grille block using pipe insulation. It helped a lot in winter and I only had to remove one (of 3 pieces) in summer when I noticed the cooling fans running more than normal). When not in use I just stick them around the spare tire.
Check my fuel log, there is a note when the grille blocks were installed and you can see
the improvement in MPG.

regards
mech

[FordFiestaS]

I'm in for the pipe insulation idea. How great, simple, cheap. Thx for the tip.

[RedDevil]

You can actually see a piece of pipe insulation at mine, upper left corner

I tried to paint them black. It looked great until the first rain storm.
Take the small diameter ones, the big ones are easily too big.
Some come with an adhesive strip, that might help you to keep them attached.
I had no strips on mine and lost one (but I had a stack of them).

I run my lower grill block all year, no problem (though it has been close to overheating once last year when stuck in a traffic jam during a record heat spell)