Ford Focus aerodynamics question

[trikkonceptz]

CHeck out the last generation Mazda Protege's. They have plenty of pep, are stylish,functional and who knows maybe better FE?

Do a comparison to find out...

[Formula413]

Originally Posted by trikkonceptz

CHeck out the last generation Mazda Protege's. They have plenty of pep, are stylish,functional and who knows maybe better FE?

Do a comparison to find out...

Little lower FE than the Focus. And they only made the hatchback in '02 and '03. Basically the same drvietrain and similar weight, but about 2 less m's per g.

[akcapeco]

Kind of a dead thread, but for the record I thought this drawing could be useful; these aerodynamic discussions aren't going away.

(edit: The ZX3 is shown here overlaying the ZXW, the ZX3 and ZX5 being largely identical save for the side door configuration).

[NeilBlanchard]

Hi,

My previous car was a 2005 ZX-5, and my wife drove a 2000 wagon. The engine in the ZX-5 is/was the higher output 16 valve 2.0 jobbie, and the wagon had/has a choice of engines (my wife's was a 16 valve 1.8L). Also, the ZX-5 tires were 16" 205 width 50 series -- they handled great, but were poor at coasting; and worse yet were very sensitive to inflation level.

The aero Cd of the hatchback is 0.36, IIANM -- not great.

[lunarhighway]

side views aren't everything

the rear angle of the c pillars is important as are the sides. the c pillars on the hatch are more angles than the wagon wich means they're more likey to generate bad vortices.

the wagon might have some more boattailing in top view, and the underbody airflow might intaract with the extended body in a more aero friendly way.

anyway that would explain better aero if that is a fact

a collegue had a wagon untill he crashed it into a car that was parked behind a bend. car was written off but he was fine and he now has a hatch.

don't think he keeps a fuellog and it was a diesel anyway, but i think he's generally happy wich the car...the hatch doesn't have that much trunkspace so if you want that go for the wagon

[cfg83]

akcapeco -

Originally Posted by akcapeco

Kind of a dead thread, but for the record I thought this drawing could be useful; these aerodynamic discussions aren't going away:

...

I love it when people make the effort to do these overlays, but isn't that the smaller 3-door Focus ZX3? Don't you want to compare the wagon to the ZX5?

CarloSW2

[QuickLTD]

The first gen US Focus all have the same WB. the only difference is the sedan and wagon are longer behind the rear wheels. The ZX5 is essentially a ZX3 with the front shorter front doors.

2003 Ford Focus - Specs

It appears they have the length wrong on the sedan. Edmunds has it listed as 174.9 But the ZX3 and ZX5 are listed the same as the link above at 168.1

[akcapeco]

I happened across the drawings in a PDF of the owners manual and remembered this thread, so hence the overlay... there was much to it at all.

For the record, the ZX3 and ZX5 are the same under their respective roofs, except for the side doors -- i.e., The platform, wheelbase, hatch and roof as with everything ahead of the a-pillar, are all identical.

[cfg83]

akcapeco -

Originally Posted by akcapeco

I happened across the drawings in a PDF of the owners manual and remembered this thread, so hence the overlay... there was much to it at all.

For the record, the ZX3 and ZX5 are the same under their respective roofs, except for the side doors -- i.e., The platform, wheelbase, hatch and roof as with everything ahead of the a-pillar, are all identical.

Ok, I didn't know the wheelbase was the same. Thanks for the correction.

CarloSW2

[aerohead]

Originally Posted by Formula413

I'm looking at (eventually) getting a 2005-2007 Ford Focus to replace my Escort. I want either a ZX5 (4 door hatchback) or a wagon. According to Edmunds.com both cars carry the same fuel economy ratings, but I tend to doubt this. In my eyes the ZX5 with it's sloping roofline is much more aerodynamic than the wagon with it's squared off rear. Am I correct in thinking the ZX5 would be likely to see higher highway fuel economy? Personally I like the look and added space of the wagon more but I do a lot of highway driving so highway fuel economy is important. For reference:

Shooting from the hip,I'd say the hatchback has more potential,as the roofline begins it's downward slope forward on the car and would allow more extension and wake reduction per length.I'd say that the flow separates at the little upsweep just above the lights.Continuing the curvature of the roof along MetroMpg's aerodynamic template line,to any point of your choice would guarantee separation-free flow.------- The wagon has same drag as hatch because it's roof is longer and separation-free,although ends in a larger potential wake do to the lack of body curvature.