Aerodynamics?

[dustboy]

What aerodynamics?

From the factory my truck got 24 mpg on the highway. Now I'm down to about 19, mostly because of the extra weight. Thinking about a fairing above the cab, because if you open the cab rear window at speed there is a ton of air getting pushed by that flat face on the box. It's not so much the few extra dollars it costs to run, but the fact that my fuel range is much shorter.

I've heard that above 45 mph, almost all of the extra fuel spent to go faster goes into pushing the air. Think about this: The Bugatti Veyron only needs 270 HP to go 150 MPH, but to reach its top speed of 250 MPH it needs the remaining 730 HP.

[burn_e]

What aerodynamics?

From the factory my truck got 24 mpg on the highway. Now I'm down to about 19, mostly because of the extra weight. Thinking about a fairing above the cab, because if you open the cab rear window at speed there is a ton of air getting pushed by that flat face on the box. It's not so much the few extra dollars it costs to run, but the fact that my fuel range is much shorter.

I've heard that above 45 mph, almost all of the extra fuel spent to go faster goes into pushing the air. Think about this: The Bugatti Veyron only needs 270 HP to go 150 MPH, but to reach its top speed of 250 MPH it needs the remaining 730 HP.

You must have a pair of strong arms to get the highlift down from there




Jokes aside, you are opening up a valid point - the range of the car. The concern about fuel consumption to save a few bucks/euros/dirhams whatever it is - seems to be a bit misplaced in our hobby which is quite a money pit in the first place.

But the range of the car is something really essential to talk about! My car (RRC) is mildly said a serious drinker. In daily use the average consumption is somewhere at 18-20 liters/100km (mixed use and almost always with AC) and jumps to 30+ in the dunes - which is our offroading. So the range of the car (without safety reserve) goes down to about 200km. :-(

This needs compensation with jerry cans, which are bulky and heavy again. So quickly the need of a roof rack comes up. This again increases the consumption...ahhh its vicious!

[JIMBO]

Heh Heh, I think he put it there, because the little holes in the HiLift shaft, bleed off air pressure buildup at the face of the cab!!

JIMBO

[chasespeed]

In some cases, as far as range, which is really more important, an aux tank would be better served, than, trying to make a brick slicker........

In the case of that cab over.... You could make a small frame, out of something stout, and a little light... maybe some hard EMT. add some lights, and then, a piece of lexan over those, with a rubber section between that and the cab.... wouldnt add much weight, but, would smooth the air flow out, which should help some. I would imagine, it would also be quieter at highway speeds. Its the same principle as fairing the roof racks... just, instead of having dead space, you have some lights in there as well... Just a thought....

Other wise, I approach the range issue, by add capacity. In my case(my cummins get 19mpg), I go 500 miles on the hwy before I start looking... but, I fill at 300 miles(approx half tank), regardless. If I am towing... then, I play it by ear so to speak....

Habits are easier to change, than the drag coefficient of your truck....

Chase

[Jnich77]

Aerodynamics??? HA. My truck has the aerodynamics of a refrigerator......

Ya know, surprisingly the first generation tundra's are relatively aerodynamic for a truck. I was shocked when i looked up the drag coefficient for it.

[Jnich77]

In the case of that cab over.... You could make a small frame, out of something stout, and a little light... maybe some hard EMT. add some lights, and then, a piece of lexan over those, with a rubber section between that and the cab.... wouldnt add much weight, but, would smooth the air flow out, which should help some. I would imagine, it would also be quieter at highway speeds. Its the same principle as fairing the roof racks... just, instead of having dead space, you have some lights in there as well... Just a thought....

I think that would be a great idea.

[Jnich77]

Habits are easier to change, than the drag coefficient of your truck....

Chase

See with me, I have the habits down..other than going much slower on the highway...aerodynamics is what I am left with.

When I do my timing belt I am going to do a under drive crank pulley and electric fans. The havey helped on previous trucks..so even if I don't get better mileage, I am sure the but dyno will approve...lol

[Jnich77]

I think its a rule of physics that you're not allowed to use the words aerodynamic and Land Rover in the same sentence. To even think about that word when you're driving something with a flat windshield is delusional.

I almost fell out of my chair laughing...lmao

[ChrisInVT]

My truck is about as aerodynamic as a plane hanger on wheels.

[sjk99]

There's an interesting thread about aerodynamic modifications for a Jeep (not all that much that isn't obvious) but the concepts should transfer to other vehicles.


http://ecomodder.com/forum/showthrea...deas-1517.html


The whole site looks pretty interesting.

Build an aerodynamic fiberglass shell.

http://ecomodder.com/forum/showthrea...ring-1175.html