Why do utes use more fuel than sedans?

[falcon convert]

Just been checking out the 50th Anniversary range at my local dealer. Very nice.
I noticed that the sedan fuel sticker was 9.9l/100kms, whereas the ute was rated at 10.6.
Wouldn't the sedan be heavier than the ute and therefore use more fuel rather than less? I guess a sedan would be more aerodynamic, but surely enough to make that much difference. Surely weight is a bigger factor in this case.
Do the utes have different gear or diff ratios?
Can some of you Falcon experts out there please explain why is it so.

[XR Martin]

Ute is heavier.
Seperate rear chassis, and also longer.

[GS608]

Larger tank though

[cedric]

cause there full of tools,esky,dog,gum boots and gravel and leaves that you didn't quite clean out last time you loaded it up

[JC807]

the utes square *** would be as aerodynamic either.

[BENT_8]

Final Drive...?

[f1tzy]

same final drive they are just heavier and probably less aerodynamic

[ute83]

Tuned a bit richer i suppose, because of the work it would do.

[falcon convert]

You're right - the ute is heavier, but only just - 1685 for the sedan v 1745 for the ute - a difference of 60 kgs or about 3.5% heavier.
But the fuel use is about 7% more.
So it still doesn't add up to me based soley on weight.
Any other theories?

[Full Noise]

Originally Posted by falcon convert

Any other theories?

I’ve got a theory. They’re driven harder.

[Burnout]

Originally Posted by Full Noise

I’ve got a theory. They’re driven harder.

Mmmm, sounds good!

[Romulus]

Originally Posted by Full Noise

I’ve got a theory. They’re driven harder.

Damn right, much harder, and faster :

My SP tips the scales at 1920kgs wet without driver or cargo. ATM it's probably weighing in at 2200kgs. 12.6l/100km is good economy though.

[Resurrection]

Originally Posted by falcon convert

You're right - the ute is heavier, but only just - 1685 for the sedan v 1745 for the ute - a difference of 60 kgs or about 3.5% heavier.
But the fuel use is about 7% more.
So it still doesn't add up to me based soley on weight.
Any other theories?

Aerodynamic drag caused by vertical rear window.

[DeviousKim]

ute drivers have a heavier foot?
Glad you started this topic, I had always thought my ute uses more fuel

[Swordsman88]

Yes, there is a weight difference. But really, this is all about aero, aero, aero. Illustrates just how much gain manufacturers have put into this area in the last 5-10 years especially. The sedan may have a bigger cab but its much superior aerodynamics mean it burns less esp on the highway. Its all about 'boundary layer' air etc. Bit beyond my understanding but basically behind the ute cab is a large rolling mass of air (think of an edy behind a wave at the beach or jetty) which in itself imparts drag. The sedan has a smooth cabin/boot in this area and the air just sticks to the body of the car till it smoothly exits behind the rear. Hence no imparted drag. Therefore lower fuel burn...

[MaTTe]

put the tailgate down and the economy should improve a little, either that or get a soft/hard lid for the tray.
But yeah, basically comes down to aero, if the ute were lighter it'd probably still use more fuel..

Isn't that why holden fans put big wings on the back of commonwhore utes? to take full advantage of any tail winds?

[balthazarr]

Originally Posted by MaTTe

put the tailgate down and the economy should improve a little, either that or get a soft/hard lid for the tray.
But yeah, basically comes down to aero, if the ute were lighter it'd probably still use more fuel..

Isn't that why holden fans put big wings on the back of commonwhore utes? to take full advantage of any tail winds?

According to Mythbusters, tailgate down is worse for fuel economy: http://www.youtube.com/watch?v=r3aqHbD-O9E

[XRSEX]

Originally Posted by balthazarr

According to Mythbusters, tailgate down is worse for fuel economy: http://www.youtube.com/watch?v=r3aqHbD-O9E

Was just about to say that! :P

[castellan]

I would say that there is really bugger all in it, sedan vs ute. but the tray back is were they use a lot more fuel on the highway.

[aussie muscle]

Originally Posted by MaTTe

put the tailgate down and the economy should improve a little,

Not according to Mythbusters. they found that the vehicle they had was 'designed' with the tailgate in mind and actually reduced efficiency with it down because it breaks the 'air bubble' that forms in the tray.

[grey_esp]

Originally Posted by aussie muscle

Not according to Mythbusters. they found that the vehicle they had was 'designed' with the tailgate in mind and actually reduced efficiency with it down because it breaks the 'air bubble' that forms in the tray.

Well i can say BA's were not designed that way. My old XLS with soft cover, out on the highway you could see the wind push the cover down into the tray just in front of the tailgate.

I know with the BA series there was defianetly different Diff ratios between sedan and XL ute which will contibute to economy differences, also up until recently the bases model utes were only available with the 4spd auto not the 6 so perhaps thats also a contributing factor.

[DeviousKim]

I have always got my toneau cover on and its just as bad really.
Sooooo would that mean the power bulge hard covers would improve the fuel efficiency or even a canopy?

The horrible aerodynamics makes a lot of sense now, more fuel is simply required to move the vehicle through the air. *goes off to look for wind tunnel tests*

edit: found something on this forum
http://www.fordforums.com.au/showthread.php?t=11237213

[henryox]

my 77 F250 4x4 averages 11.5 / 100, hwy plus city, it has a style side and canopy

[JK EX CHASER]

They carry a lot more tons,that is the reason it uses 0.7L\100km more fuel.

[1TUFFUTE]

my guess is the extra percentage un accounted for with the weight gains is made up with the heavier foot...or more confident drivind style of a ute with so much more vision available. Dont forget the ford guys who worked these numbers out test drove them aswell...lol

[04baford]

i can pull better full economy out of my ute than a sedan ive got 04 ba xls with a cannopy on the back ive had it around .08/100ks loaded

[dole bludger]

Does the ute sit higher off the ground(aero drag)? or maybe they test the ute with a load in the tray? plus do the utes still have the radio antenna on the roof(aero drag)?
sorry I can't answer any questions, just making more.

[GYRKIN GT]

The fuel consumption tests are carried out in a Lab by the vehicle's manufacturer and the data is then passed onto the relevant government authority, The Dept of Transport and Regional Services. The "urban" part of the test is simulated by stop - start type driving as you would expect in any city type driving. The "Extra Urban" (Highway) part is simulated by a constant smooth type of driving as you would expect on any motorway. Environmental factors play no part (wind etc), nor do aerodynamic features (Eg. tailgate down) factor into the test. Picture your car sitting in a workshop being driven on a device similar to a dyno (but not a dyno) and that is how the test is conducted. With that in mind, barring any gearing differences between the ute and the sedan, I imagine you'd have to look at the different weight issues. Maybe this can explain the economy differences?

The other possibility/variable would be the manufacturer's standard tune for the ute compare to the standard tune for the sedan?

[Antwon]

Are you looking at N/A or turbo? Becuase as far as im aware in the N/A's the sedan comes in both 5 and 6 speed auto, and the ute only comes in 5 speed auto. This could be why? Your looking at the specs for a 6 speed sedan and a 5 speed ute? I could be wrong though.

[falcon convert]

I was comparing a 50th anniversary XR6 normally aspirated six speed auto ute with a 50th anniversary XR6 normally aspirated six speed auto sedan. The only difference was one was a ute and one was a sedan. Heck they were even the same colour!!!!(so no one come back and tell me the red one uses more fuel because red cars go faster)