Fuel Energy consumption in a typical Gasoline vehicle

Fuel Energy consumption in a typical Gasoline vehicle

As we discussed in last article, in a typical Petrol (Gasoline) vehicle only ~15% of energy is utilized to drive the vehicle. As to understand where we can improve the energy efficiency it is important to know where we are having maximum losses. Once again we will go through where is the fuel energy consumed in a typical Petrol (Gasoline) vehicles.

 (Data source: U.S. Dept. of Energy)

Diesel engines generally achieve greater fuel efficiency than petrol (gasoline) engines because of high energy efficiency of Diesel engines and latest advancement in diesel technology.

 *Currently I am not having exact data for diesel engine from a reliable source. once available I will share it later.

Latest Technologies in the Automotive field 

The majority of the chemical energy of is lost by the engine and driveline inefficiencies. Current focus is on improving powertrain efficiency. In this article we will discuss what all are the upcoming technologies and how much fuel economy improvement it offers.

Most of the new technologies come in below two categories

-          Engine Technologies (which improves engine efficiencies)

-          Transmission Technologies (which improves transmission efficiencies)

Apart from these two categories there can be some more technologies such as Improved aerodynamic design, latest tires technology (to reduce rolling resistance), better alternator design to reduce loss in accessories etc. by which we can improve the fuel economy of the vehicle. 

Engine Technologies

Variable Valve Timing & Lift (5%)

Variable Valve Timing & Lift improve engine efficiency by optimizing the flow of fuel & air into the engine for various engine speeds. It is a generic term for an automobile piston engine technology. VVT allows the lift, duration or timing (in various combinations) of the intake and/or exhaust valves to be changed while the engine is in operation.

Cylinder Deactivation (7.5%)

Cylinder deactivation is used to reduce the fuel consumption and emissions of an internal combustion engine during light load operation. In typical light load driving the driver uses only around 30 percent of an engine's maximum power. During these conditions the full displacement of engine is not required, the displacement can be reduced the by deactivating some cylinders. Cylinder deactivation will reduce pumping losses and result in better fuel efficiency. It is achieved by keeping the intake and exhaust valves closed for a particular cylinder.

Turbochargers & Superchargers (7.5%)

Turbochargers and superchargers are fans that force compressed air into an engine's cylinders. A turbocharger fan is powered by exhaust from the engine, while a supercharger fan is powered by the engine itself.  Both technologies allow more compressed air and fuel to be injected into the cylinders, generating extra power from each explosion. This allows manufacturers to use smaller engines without sacrificing performance or to increase performance without lowering fuel economy.

Integrated Starter/Generator (ISG) Systems (8%)

Integrated Starter/Generator (ISG) Systems also known as Start-Stop system automatically turn the engine off when the vehicle comes to a stop and restart it instantaneously when the accelerator is pressed so that fuel isn't wasted for idling. In addition, regenerative braking is often used to convert mechanical energy lost in braking into electricity, which is stored in a battery and used to power the automatic starter.

Direct Fuel Injection (11-13%)

In conventional multi-port fuel injection systems, fuel is injected into the port and mixed with air before the air-fuel mixture is pumped into the cylinder. In direct injection systems, fuel is injected directly into the cylinder so that the timing and shape of the fuel mist can be precisely controlled. This allows higher compression ratios and more efficient fuel intake, which deliver higher performance with lower fuel consumption.

Variable Compression (9%)

A variable compression ratio (VCR) engine is able to operate at different compression ratios, depending on a particular vehicle's needs. Thus, a VCR engine is optimized for the full range of driving conditions, such as acceleration, speed, and load.

HCCI (15%)

Presently, the overriding ICE development goals are to make the diesel engine as clean as the gasoline engine, while making the gasoline engine as efficient as the diesel engine. HCCI (Homogeneous Charge Compression Ignition) engines combine elements of both.

Switching to Diesel (30%)

Diesel engines have better fuel economy per volumetric measure than typical gasoline engines by virtue of diesel's greater energy density. The fuel savings of diesel versus gasoline are typically in the 20-30% range.

 

Hybridization (5-30%)

A hybrid vehicle is a vehicle with at least two different energy converters and two different energy storage systems (on-board the vehicle) for the purpose of vehicle propulsion. Electric power is the mostly used as second source of population. So term Hybrid vehicle is mostly used for hybrid electric vehicle. Hybridization can play a major part in improving vehicles fuel efficiency.

Transmission Technologies

Continuously Variable Transmissions (CVTs) (6%)

Most conventional transmission systems control the ratio between engine speed and wheel speed using a fixed number of metal gears. Rather than using gears, the CVTs use a pair of variable-diameter pulleys connected by a belt or chain that can produce an infinite number of engine/wheel speed ratios.

Automated Manual Transmissions (AMTs) (6%)

Automated Manual Transmissions (AMTs) combine the efficiency of manual transmissions with the convenience of automatics (gears shift automatically).

Manual transmissions are lighter than conventional automatic transmissions and suffer fewer energy losses. However, most drivers prefer the convenience of an automatic. AMT operates similarly to a manual transmission except that it does not require clutch actuation or shifting by the driver. Automatic shifting is controlled electronically (shift-by-wire) and performed by a hydraulic system or electric motor. In addition, technologies can be employed to make the shifting process smoother than conventional manual transmissions.

Other Technologies

Vehicle Downsizing & Improving Aerodynamic

Meeting future emission standards will also impact vehicle design. The impact will likely be smaller, lighter vehicles that require less energy to operate. Also the aerodynamics will be improved to get better fuel efficiency as it can reduce air drag to significant limits.

We will cover each and every technology in details in future articles.

**Few of the above technologies are only applicable to one kind of engine Gasoline or Diesel while others are applicable to both. We will discuss about that later