CAR ENERGY EFFICIENCY - SAVING THE PENNIES

YOKOHAMA DNA EARTH 1

intelligent Dual and Sequential Ignition (i-DSI) engine

Diagram above showed car energy distribution

http://www.fueleconomy.gov/FEG/atv.shtml

1) AERODYNAMICS - DRAG COEFFICIENT

-Smoother vehicle shapes have already reduced drag significantly, but further reductions of 20-30% are possible.

2) AIR FUEL RATIO (AFR) = MAGIC FIGURE IS 14.7 TO 1

LESS THAN 14.7 TO 1 = RICH MIXTURE

MORE THAN 14.7 TO 1 = LEAN MIXTURE

in Naturally aspirated engines (powered by octane) Max power with AFR ranging 12.5 to 13.3

The main drawback of lean burning is the large amount of NOx being generated at relatively high air/fuel ratios.

CHOOSE the engine with lean burning potential.

3) LOWERING ROLLING RESISTANCE TIRE 

IDEALLY = smooth ride, minimize noise, & good traction in a variety of weather conditions. 

But they are rarely optimized for efficiency. Tires can cause a sginificant amount of drag while driving. Therefore in Hybrid cars, special tires that are stiffer and inflated to a higher pressure than conventional tires. The result is that they cause about half the drag of regular tires.

4) WINDOWS UP vs DOWN

Studies showed that low velocity, window down improve fuel efficiency

However, driving at high velocity (>90km/h), window up is better than window down due to aerodynamics and drag coefficient.

5) START STOP SYSTEM (integrated starter/generator)

Helps to cut energy loss during traffic jams. Stop the engine when brake is pressed, restarting it instantaneously when the accelerator is pressed.

Currently it is used in Volkswagen, BMW & Citroën models.

Toyota and Mazda will be introducing stop-start technology in 2009 year model.

Renault will introduce the technology in all of its European models by 2010.

6) DRIVELINE LOSSES

- Energy is lost in the transmission and other parts of the driveline. Technologies, such as automated manual transmission (AMT) and continuously variable transmission (CVT), are being developed to reduce these losses.

7) USE LIGHT WEIGHT MATERIALS

- Reducing the overall weight of a car is one easy way to increase the mileage.

Composite materials like carbon fiber or lightweight metals like aluminum and magnesium can be used to reduce weight.

Reference:-

1) http://auto.howstuffworks.com/ten-green-driving-tips.htm

2) http://en.wikipedia.org/wiki/Lean_burn

3) http://www.bkkautos.com/2009-Honda-City-Chalks-Up-4500-Sales-in-2-Weeks

4) http://en.wikipedia.org/wiki/Start-stop_system

5) http://www.fueleconomy.gov/FEG/tech_adv.shtml

6) http://en.wikipedia.org/wiki/Honda_L_engine

7) http://www.ukipme.com/engineoftheyear/

NOTES:-

1) 62% of the fuel's energy is lost in the internal combustion engine (ICE)

2) ICE engines are very inefficient at converting the fuel's chemical energy to mechanical energy, losing energy to engine friction, pumping air into and out of the engine, and wasted heat.

3) diesels are about 30-35% more efficient than gasoline engines, and new advances in diesel technologies and fuels are making these vehicles more attractive.

4) Honda’s new Advanced VTEC (AVTEC) engine combines continuously variable valve lift and timing control with the continuously variable phase control of valve timing to achieve a good combination of better performance, fuel economy, and lower emissions.

5) Conventionally, one spark plug per cylinder but the i-DSI engine uses a radical twin-spark ignition system with just two valves per cylinder.

6) At lower velocity, spark plug nearest the inlet valve is fired much earlier than usual while the plug nearest the exhaust valve is fired later than usual.

7) At higher velocity, the sparks are fired simultaneously.In a normal engine, fuel and air enters the cylinder of an engine through the inlet valve, designers concentrate on optimizing the swirl of the mixture to ensure fuel is atomized thoroughly and evenly.

8) The 1NZ-FXE Hybrid Synergy Drive in the Toyota Prius has won several International Engine of the Year awards

9) 1NZ-FXE based on Atkinson cycle rather than the conventional Otto cycle.

10) Michelin XM1 vs Yokohama DNA EARTH 1 - which one better???