Archive for April, 2009

Some ideas for low energy and efficient cars

What is a more efficient car ?

A car that has a low cost, is reliable, is light-weight, has good performance and high mpg.

More Lightweight and Secure Cars

  • F=m.a, the smaller the mass the higher the acceleration for a given power.
  • Avoid not needed stuff, there is lot…

More Efficient Motors

Mechanical Devices

  • Turbo charging: reuse energy from exhaust gas to compress inlet air, less pollution and more power. ( Difficult to apply on motor bikes, due to so called lag but should work. Water intercoolers help to limit turbo lag due to their size.
  • Multi-Stage turbo charging for diesel: small turbo followed by a bigger one. Given a small displacement motor it is possible to achieve very high power output, 200 BHP/liter is achievable. Water intercoolers are very helpful in such case to limit lag.
  • Compounding: takes kinetic energy from exhaust gas using a turbine and gears reduction to crank-shaft  (, about 20 to 25% more torque (and thus power). Can be use on motor bikes, there is no lag as for a turbo.
  • Kinetic Energy Recovery: takes energy when braking to spin quickly a disc, helps to have some amounts of torque for acceleration.  Better power/weight ratio than batteries, that why it is used in Formula 1. ( I think it is also very useful on motor bikes with a tiny hydraulic motor on the front wheel.
  • Variable Compression Ratio: more efficient motor on low and mid range. ( For gasoline engine, water injection can be used to  save precious gasoline while achieving more power.
  • Constant Variable Transmission: can replace a whole gearbox and is lighter (


  • Electric water pump: low and mid-range needed coolant flow is bigger than high rpm. Most mechanical water pump are over designed. This is very useful for trucks and heavy duty motors.
  • Alternator/Starter Motor: limits weight and can be used to put additional power on low to mid range revs.
  • Higher voltage: cost saving for copper and save weight.(Power=Voltage.Intensity)
  • Compounding, Kinetic Energy Recovery: can be used to generates electricity, to refill batteries.
  • Thermal Energy from Motor: takes thermal energy and generates electricity, helps to refill batteries.
  • Supercapacitor: a reserve of electric power to smooth power demand on batteries. It allows faster acceleration. (

More efficient cars need more efficient traffic lights control !

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