The carbon footprint calculation made by the Renewable Fuels and Sustainable Transportation Branch of the American Solar Energy Society after taking into account all the external factors of manufacturing and refueling shows that a small car can travel 30 miles on 1gal gasoline, and the tailpipe emits a carbon footprint of CO2 3.5t per year. This figure should also take into account the 4.5t 'upstream' external emissions carbon footprint of car production, for a total of 8t. In addition, solar- and wind-charged electric vehicles have also been calculated to be 60 to 3,000 times more efficient than biofuel engines. This will make zero-emission electric vehicles and plug-in hybrids more attractive.
For electric vehicles powered by batteries, the actual range of traditional lead-acid batteries is limited to 20~30mi, and modern lithium-ion batteries can increase the range to 40mi or even 200mi. For conventional hybrid vehicles, the battery is used for low power operation and the internal combustion engine power is used for acceleration. The IC motor stops when the car is parked, and drives when it is loaded. Heavy-duty hybrids have no efficiency advantage over conventional IC vehicles, and when driven over long distances, hybrids lose their efficiency advantages. A plug-in hybrid is a hybrid vehicle that uses a large battery stack that can be charged from the grid. In a typical situation, it can travel about 40mi on battery power alone. CNG vehicles are typically used in fleets, but the lightweight Honda Civic GX is also available in the utility market. In some major metropolitan areas, CNG fuel is supplied from filling stations, but the scope of supply is limited by the need for enhanced high-pressure fuel tankers. Its main advantage is low greenhouse gas emissions: about 0.53lb of CO2 per mile. 16 states in the United States have CNG filling stations for private vehicles. According to local pricing, the fuel cost can be reduced by about $2/gal equivalent.
Turbocharged diesel internal combustion engines have more energy due to the use of diesel fuel, which contains more energy than gasoline. They can operate at maximum duty cycle conditions without modification for operation with any biodiesel blend. Fuels using oils with high biomass content, however, condense at low temperatures, and for this reason these engines are often powered by fossil diesel in winter and vegetable oil in summer.
1. The use of different fuels has different carbon footprints
The relevant data are as follows:
Gasoline burning in the carbon footprint of a piston engine produces about 19.561b CO2/gal (2.34kg/L);
Diesel fuel carbon footprint produces approximately 22.38lb CO2/gal (2.68kg/L);
Biofuel carbon footprint (vegetable oil and ethanol) yields about 3.31b CO2/gal (0.39kg/L);
Burning coal with a carbon footprint in modern power plants produces about 1.371b CO2/(kW•h) (0.62kg/(kW•h)).
2. Low carbon footprint of using biofuels (E85 or B100)
The carbon footprint of any electric vehicle powered by a non-carbon source (photovoltaic, wind, nuclear) is: 01b CO2/mi.
3. Carbon emissions of any PHEV (eg Prius PHEV, Volt PHEV) driven in electric mode only
The carbon footprint of the Honda Insight car is 0.061b CO2/mi;
Volkswagen TDI car has a carbon footprint of 0.071b CO2/mi;
Toyota Prius, Honda Civic Hybrid or PHEV with a carbon footprint of 0.091b CO2/mi in hybrid drive mode;
A typical old motorcycle or small car runs at 42mi/gal and has a carbon footprint of 0.091b CO2/mi;
Mercedes Smart has a carbon footprint of 0.11b CO2/mi;
Nissan Altima Hybrid/Toyota Camry Hybrid (drive train) has a carbon footprint of 0.121b CO2/mi;
Various small cars (30mi/gal) have a carbon footprint of 0.131b CO2/mi;
Honda Accord Hybrid has a carbon footprint of 0.151b CO2/mi;
The carbon footprint of the Chevy Malibu RO powered/Saturn Aura Green Line car is 0.151b CO2/mi;
The Lexus GS450h has a carbon footprint of 0.17lb CO2/mi;
Ford Escape Hybrid/Toyota Highlander Hybrid SUVs have a carbon footprint of 0.171b CO2/mi;
The Lexus LS600HL has a carbon footprint of 0.191b CO2/mi.
4. Minimum carbon footprint for using fossil fuels (gasoline, diesel, natural gas or coal-fired electricity)
Honda Insight car with a minimum carbon footprint of 31b CO2/mi;
Electric vehicles or PHEVs driven only in electric mode, with a minimum carbon footprint of 341b CO2/mi; Toyota Prius, with a minimum carbon footprint of 431b CO2/mi;
Honda Civic Hybrid or PHEV driven in hybrid mode with a minimum carbon footprint of 471b CO2/mi;
A typical old motorcycle or small car (42mpg) with a minimum carbon footprint of 471b CO2/mi;
Mercedes Smart cars with a minimum carbon footprint of 491b CO2/mi;
Volkswagen TDI car (or similar) with a minimum carbon footprint of 51b CO2/mi;
Honda Civic GX with a minimum carbon footprint of 531b CO2/mi;
Nissan Altima/Toyota Camry hybrid with a minimum carbon footprint of 591b CO2/mi;
The minimum carbon footprint of any small car (30mpg) is 651b CO2/mi;
Chevy Malibu/Saturn Aura hybrid with a minimum carbon footprint of 721b CO2/mi;
Honda Accord Hybrid with a minimum carbon footprint of 751b CO2/mi;
Lexus GS450h with a minimum carbon footprint of 821b CO2/mi;
Ford Escape/Toyota Highlander hybrid SUVs with a minimum carbon footprint of 851b CO2/mi;
Lexis LS600HL with a minimum carbon footprint of 93Lb CO2/mi.
Under the shadow of the global economic crisis, EU member states announced in early November 2008 to reset the 2015 vehicle CO2 emission limits. The 27 member states have unanimously agreed to defer the CO2 emissions target for new cars by three years to 2015. With the same environmental goals, the carbon footprint of new cars sold in the EU will be no greater than 130g CO2/km. The Volkswagen Golf ranks among the most popular cars in Europe and currently emits between 119 and 174g CO2/km, depending on engine type and size. For all cars, the carbon footprint now averages 158g CO2/km. Limiting CO2 emissions to 130g CO2/km by 2015 is the goal of the entire European automotive industry. In Italy, Fiat is targeting 122g CO2/km, while in France the Renault and Peugeot-Citroen will achieve 126g CO2/km and 127g CO2/km respectively. For Volkswagen, the limit will be 132g CO2/km.