Driving More Efficiently

Drive Sensibly
Aggressive driving (speeding, rapid acceleration and braking) wastes gas. It can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town. Sensible driving is also safer for you and others, so you may save more than gas money.
Fuel Economy Benefit : 5-33%
Equivalent Gasoline Savings : $0.08-$0.55/gallon

Observe the Speed Limit
While each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 60 mph.
You can assume that each 5 mph you drive over 60 mph is like paying an additional $0.24 per gallon for gas. Observing the speed limit is also safer.
Fuel Economy Benefit : 7-23%
Equivalent Gasoline Savings : $0.12-$0.38/gallon


Remove Excess Weight
Avoid keeping unnecessary items in your vehicle, especially heavy ones. An extra 100 pounds in your vehicle could reduce your MPG by up to 2%. The reduction is based on the percentage of extra weight relative to the vehicle's weight and affects smaller vehicles more than larger ones.
Fuel Economy Benefit : 1-2%/100 lbs
Equivalent Gasoline Savings: $0.02-$0.03/gallon

Avoid Excessive Idling
Idling gets 0 miles per gallon. Cars with larger engines typically waste more gas at idle than do cars with smaller engines.

Use Cruise Control
Using cruise control on the highway helps you maintain a constant speed and, in most cases, will save gas.

Use Overdrive Gears
When you use overdrive gearing, your car's engine speed goes down. This saves gas and reduces engine wear.

what are HEVs?

Hybrid-electric vehicles (HEVs) combine the benefits of gasoline engines and electric motors and can be configured to obtain different objectives, such as improved fuel economy, increased power, or additional auxiliary power for electronic devices and power tools, also known as HEVs or hybrids. Present-day hybrids are equipped with ICEs and electric motors. A hybrid's ICE engine, as in any ICE-powered car, produces power through continuous, controlled explosions that push down pistons connected to a rotating crankshaft. That rotating force (torque) is ultimately transmitted to the vehicle's wheels.

A hybrid's electric motor is energized by a battery, which produces power through a chemical reaction. The battery is continuously recharged by a generator that—like the alternator of a conventional car—is driven by the ICE.

Hybrids can have a parallel design, a series design, or a combination of both:

• In a parallel design, the energy conversion unit and electric propulsion system are connected directly to the vehicle's wheels. The primary engine is used for highway driving; the electric motor provides added power during hill climbs, acceleration, and other periods of high demand.
  
• In a series design, the primary engine is connected to a generator that produces electricity. The electricity charges the batteries, which drive an electric motor that powers the wheels. HEVs can also be built to use the series configuration at low speeds and the parallel configuration for highway driving and acceleration.

Some of the advanced technologies typically used by hybrids include

• Regenerative BrakingThe electric motor applies resistance to the drivetrain causing the wheels to slow down. In return, the energy from the wheels turns the motor, which functions as a generator, converting energy normally wasted during coasting and braking into electricity, which is stored in a battery until needed by the electric motor.
  
• Electric Motor Drive/Assist
  The electric motor provides additional power to assist the engine in accelerating, passing, or hill climbing. This allows a smaller, more efficient engine to be used. In some vehicles, the motor alone provides power for low-speed driving conditions where internal combustion engines are least efficient.
  
• Automatic Start/Shutoff
  Automatically shuts off the engine when the vehicle comes to a stop and restarts it when the accelerator is pressed. This prevents wasted energy from idling.

Biodiesel

Auto mobile automover car shipping parts transport engine system

Biodiesel is a form of diesel fuel manufactured from vegetable oils, animal fats, or recycled restaurant greases. It is safe, biodegradable, and produces less air pollutants than petroleum-based diesel.

Biodiesel can be used in its pure form (B100) or blended with petroleum diesel. Common blends include B2 (2% biodiesel), B5, and B20. B2 and B5 can be used safely in most diesel engines. However, most automobile vehicle manufacturers do not recommend using blends greater than 5%—using higher blends will void some automobile engine warranties. Check with your owner’s manual or vehicle automobile manufacturer to determine the right blend for your automobile vehicle.

Advantages

* Domestically produced from non-petroluem, renewable automobile resources
* Can be used in most diesel engines, especially newer ones
* Less air pollutants (other than nitrogen oxides) and greenhouse gases
* Biodegradable
* Non-toxic
* Safer to handle

Disadvantages

* Use of blends above B5 not yet warrantied by automobile parts makers
* Lower fuel economy and power (10% lower for B100, 2% for B20)
* Currently more expensive
* More nitrogen oxide fuel emissions
* B100 generally not suitable for use in low temperatures
* Concerns about B100's impact on engine cooling system durability

Biodiesel prices vary across the country and tend to be slightly higher than those for petroleum diesel. Visit DOE's Alternative Fuel Station Locator for locations of service stations selling biodiesel.