Total consumption distribution table

[tollo]

What do you think about this kind of table? done allready ? I think that it would help to see the big picture.

Assume that speed is 65km/h / 40mph and "typical car" (unmoded)

Aerodynamics (50%) (0.3 drag factor):

Optimal shape 15,00%
Rear 11,00%
Bottom 7,50%
Mirrors 1,50%
Front 6,00%
Sides 3,00%
Tyres 2,00%
Antenna 0,25%
door handles 0,25%
Wipers 0,25%
Wheel covers 0,25%
Wheel skirt rear 1,00%
Wheel skirt front 1,00%
Front Grill 1,00%

Others (50%):

electricity = alternator 10,00% 0.2liter/100W
Gears 10,00%
Tyrerollingresistance 5,00%
Oil- and waterpump 10,00%
Motor friction loses 7,50%
termodynamic loses 7,50%

I made an openoffice-table from these, but I can't post links. Table is just rough and needs much development.

[Daox]

How would you ever measure all that stuff for a vehicle?

[tollo]

There is no need to do any new measurements. This site is full of measurements and just keep the total percents at 100% (check sum) At speed of 40mph it's about 50-50 aerodynamic - other loses. (according story from front page: "214 mpg with DIY aerodynamic fairings on a Honda 125cc motorbike" )

I would try to send more exact table in couple of days. I'll also add some source of informations.

[Wonderboy]

You didn't get the PM Daox? He's the omniscient grand master of information - he sees not in colors, hues, and light but in raw, tabular data about everything. If you saw what he sees, you'd go completely insane.


j/k. A general table of this nature with very general numbers may be helpful to identify the "lowest hanging fruit" but these numbers look far too round to be useful - I could be wrong though. Someone crazy enough to do all the testing (like Randy's accessory wattage draw data in Darin's alternator article) might take a crack at what you're trying to do here. Good luck and welcome. Sorry to poke some fun

[gone-ot]

...also, that "general table" data can be "scaled" UP & DOWN (linearly or exponentially) to approximate other vehicle speeds.

[Big Dave]

You've underestimated engine frictionalosses and overestimated gear losses.

At freeway engine speeds engine frictional HP rivals aero HP.

[tollo]

Here is little bit more stuff. I have lot of stuff to explain, so I start with something.

First this link:
Advanced Technologies & Energy Efficiency

Like you can see, that total energy efficiency of the cars is very poor. Only 2.6% of the energy goes for example to aerodynamical drag. Driveline losses are about 30% of the motor output power. How this is possible ? How it's easy to get 10% fuelconsumption improvement with small aerodynamical mods even though only 2.6% of the total energy goes to aerodynamical drag ? (good thing to think through)

In energy calculations is important to know that what you are calculating. So reason why driveline loses are small in my table, is that aerodynamical loses and percents include its part of driveline loses. Energy comes from fuel and all loses that come on the way to aerodynamical drag are included to aerodymamical drag percents (50%).

Aerodynamical and alternator part looks like ok. I trying to think way to divide others. (I can list only "end users of energy" and that's why the other section is harder) Table could be much more complicated but try start with quite simple (if this kind of table can be simple )

Here is the table at the moment in open office format:
www.student.oulu.fi/~torvinen/consumption.ods

We'll see if this is going to be totally useless... I try to show that it's not