Reducing greenhouse gas emissions

For every litre of petrol used in a motor vehicle, 2.3 kilograms of carbon dioxide (CO2 ), a major greenhouse gas, is released from the exhaust. The Australian transport sector accounts for around 76 million tonnes of Australia's total net greenhouse gas emissions, representing 13.5 per cent of Australia's total emissions.

Emissions from different fuels

Fuels differ in the amount of carbon and energy they contain as well as other characteristics, with implications for fuel economy and greenhouse emissions. The table below lists the amount of CO2 emitted from the exhaust for each litre of a particular fuel covered by the calculator.

CO2 Tailpipe Emissions/Litre of Fuel Consumed

Fuel Type CO2 Emissions

Petrol 2.3 kg
LPG 1.6 kg
Diesel 2.7 kg

It might seem odd that a greater weight of emissions is produced than the weight of a litre of fuel, but this is because of the addition of oxygen from the atmosphere to the fuel during combustion to form CO2.

This is not the end of the story because it also matters how much fuel is consumed to travel a given distance. LPG has lower greenhouse emissions per litre of fuel consumed than petrol, but also has a lower energy content. Therefore equivalent vehicles tend to consume more of LPG than petrol to travel a given distance. In the case of diesel, its greenhouse emissions per litre are higher than petrol, but engines designed to operate on diesel tend to be far more fuel-efficient than petrol engines. To be sure that one vehicle has lower greenhouse emissions than another use the calculator provided.

You can make a difference

Purchasing a vehicle with low fuel consumption and driving it efficiently can make a real difference to the amount of greenhouse gas emissions it produces. The following table gives an indicative guide to annual CO2 tailpipe emissions from petrol vehicles travelling 15,000 kilometres annually.

CO2 Tailpipe Emissions from Petrol Vehicles

Fuel Consumption Annual CO2 Emissions

6 L/100km 2160 kg
8 L/100km 2880 kg
10 L/100km 3600 kg
12 L/100km 4320 kg

Money Doesn't Grow on Trees, But Gasoline Might

Researchers have made a breakthrough in the development of "green gasoline," a liquid identical to standard gasoline yet created from sustainable biomass sources like switchgrass and poplar trees.

George Huber poses with a vial of green gasoline compounds.

Reporting in the cover article of the April 7, 2008 issue of Chemistry & Sustainability, Energy & Materials (ChemSusChem), chemical engineer and National Science Foundation (NSF) CAREER awardee George Huber of the University of Massachusetts-Amherst (UMass) and his graduate students Torren Carlson and Tushar Vispute announced the first direct conversion of plant cellulose into gasoline components.

In the same issue, James Dumesic and colleagues from the University of Wisconsin-Madison announce an integrated process for creating chemical components of jet fuel using a green gasoline approach. While Dumesic's group had previously demonstrated the production of jet-fuel components using separate steps, their current work shows that the steps can be integrated and run sequentially, without complex separation and purification processes between reactors.

While it may be five to 10 years before green gasoline arrives at the pump or finds its way into a fighter jet, these breakthroughs have bypassed significant hurdles to bringing green gasoline biofuels to market.

"It is likely that the future consumer will not even know that they are putting biofuels into their car," said Huber. "Biofuels in the future will most likely be similar in chemical composition to gasoline and diesel fuel used today. The challenge for chemical engineers is to efficiently produce liquid fuels from biomass while fitting into the existing infrastructure today."

For their new approach, the UMass researchers rapidly heated cellulose in the presence of solid catalysts, materials that speed up reactions without sacrificing themselves in the process. They then rapidly cooled the products to create a liquid that contains many of the compounds found in gasoline.

The entire process was completed in under two minutes using relatively moderate amounts of heat. The compounds that formed in that single step, like naphthalene and toluene, make up one fourth of the suite of chemicals found in gasoline. The liquid can be further treated to form the remaining fuel components or can be used "as is" for a high octane gasoline blend.

"Green gasoline is an attractive alternative to bioethanol since it can be used in existing engines and does not incur the 30 percent gas mileage penalty of ethanol-based flex fuel," said John Regalbuto, who directs the Catalysis and Biocatalysis Program at NSF and supported this research.

"In theory it requires much less energy to make than ethanol, giving it a smaller carbon footprint and making it cheaper to produce," Regalbuto said. "Making it from cellulose sources such as switchgrass or poplar trees grown as energy crops, or forest or agricultural residues such as wood chips or corn stover, solves the lifecycle greenhouse gas problem that has recently surfaced with corn ethanol and soy biodiesel."

Beyond academic laboratories, both small businesses and Fortune 500 petroleum refiners are pursuing green gasoline. Companies are designing ways to hybridize their existing refineries to enable petroleum products including fuels, textiles, and plastics to be made from either crude oil or biomass and the military community has shown strong interest in making jet fuel and diesel from the same sources.

"Huber's new process for the direct conversion of cellulose to gasoline aromatics is at the leading edge of the new ‘Green Gasoline' alternate energy paradigm that NSF, along with other federal agencies, is helping to promote," states Regalbuto.

Not only is the method a compact way to treat a great deal of biomass in a short time, Regalbuto emphasized that the process, in principle, does not require any external energy. "In fact, from the extra heat that will be released, you can generate electricity in addition to the biofuel," he said. "There will not be just a small carbon footprint for the process; by recovering heat and generating electricity, there won't be any footprint."

The latest pathways to produce green gasoline, green diesel and green jet fuel are found in a report sponsored by NSF, the Department of Energy and the American Chemical Society entitled "Breaking the Chemical and Engineering Barriers to Lignocellulosic Biofuels: Next Generation Hydrocarbon Biorefineries". In the report, Huber and a host of leaders from academia, industry and government present a plan for making green gasoline a practical solution for the impending fuel crisis.

"We are currently working on understanding the chemistry of this process and designing new catalysts and reactors for this single step technique. This fundamental chemical understanding will allow us to design more efficient processes that will accelerate the commercialization of green gasoline," Huber said.

"Gas-Saving" Products: Fact or Fuelishness?

Gas prices are up, and so is the volume of advertising for "gas-saving" products. When gasoline prices rise, consumers often look for ways to improve fuel efficiency. Although there are practical steps you can take to increase gas mileage, the Federal Trade Commission (FTC) warns you to be wary of any gas-saving claims for automotive devices or oil and gas additives. Even for the few gas-saving products that have been found to work, the savings have been small.

"Gas-Saving" Advertising Claims

Be skeptical of the following kinds of advertising claims.

• "This gas-saving product improves fuel economy by 20 percent."
  
  - Claims usually tout savings ranging from 12 to 25 percent. However, the Environmental Protection Agency (EPA) has evaluated or tested more than 100 alleged gas-saving devices and has not found any product that significantly improves gas mileage. In fact, some "gas-saving" products may damage a car's engine or cause substantial increases in exhaust emissions.
  The gas-saving products on the market fall into clearly defined categories. Although the EPA has not tested or evaluated every product, it has tried to examine at least one product in each category. See "Devices Tested by EPA" at the end of this brochure for category descriptions and product names.
  
• "After installing your product on my car, I got an extra 4 miles [6.4 kilometers] per gallon [3.8 liters]."
  
  - Many ads feature glowing testimonials by satisfied customers. Yet, few consumers have the ability or the equipment to test for precise changes in gas mileage after installing a gas-saving product. Many variables affect fuel consumption, including traffic, road and weather conditions, and the car's condition.
  For example, one consumer sent a letter to a company praising its "gas-saving" product. At the time the product was installed, however, the consumer also had received a complete engine tune-up - a fact not mentioned in the letter. The entire increase in gas mileage attributed to the "gas-saving" product may well have been the result of the tune-up alone. But from the ad, other consumers could not have known that.
  
• "This gas-saving device is approved by the Federal government."
  
  - No government agency endorses gas-saving products for cars. The most that can be claimed in advertising is that the EPA has reached certain conclusions about possible gas savings by testing the product or by evaluating the manufacturer's own test data. If the seller claims that its product has been evaluated by the EPA, ask for a copy of the EPA report.

Product Complaints and Refunds

If you're dissatisfied with a gas-saving product, contact the manufacturer and ask for a refund. Most companies offer money-back guarantees. Contact the company, even if the guarantee period has expired.

If you're not satisfied with the company's response, contact your local or state consumer protection agency or the Better Business Bureau.

Shifting Gears: Real Money-Saving Steps

There are numerous no- or low-cost steps you can take to combat rising gas prices. The most important place to start is at the gas pump; buy only the octane level gas you need. All gas pumps must post the octane rating of the gas under the FTC's Fuel Rating Rule. Remember, the higher the octane, the higher the price. Check your owner's manual to determine the right octane level for your car.

Here are some additional tips to help you get better gas mileage.

Drive more efficiently

• Stay within posted speed limits. The faster you drive, the more fuel you use. For example, driving at 65 miles per hour (mph), rather than 55 mph, increases fuel consumption by 20 percent. Driving at 75 mph, rather than 65 mph, increases fuel consumption by another 25 percent.
• Use overdrive gears. Overdrive gears improve the fuel economy of your car during highway driving. Your car's engine speed decreases when you use overdrive. This reduces both fuel consumption and engine wear.
• Use cruise control. Using cruise control on highway trips can help you maintain a constant speed and, in most cases, reduce your fuel consumption.
• Anticipate driving situations. If you anticipate traffic conditions and don't tailgate, you can avoid unnecessary braking and acceleration, and improve your fuel economy by 5 to 10 percent. In city driving, nearly 50 percent of the energy needed to power your car goes to acceleration. Go easy on the gas pedal and brakes. "Jack-rabbit" starts and sudden stops are wasteful.
• Avoid unnecessary idling. Turn off the engine if you anticipate a lengthy wait. No matter how efficient your car is, unnecessary idling wastes fuel, costs you money and pollutes the air.
• Combine errands. Several short trips taken from a cold start can use twice as much fuel as one trip covering the same distance when the engine is warm.
• Remove excess weight from the trunk. Avoid carrying unneeded items, especially heavy ones. An extra 100 pounds in the trunk reduces a typical car's fuel economy by one to two percent.

Maintain your car

• Keep your engine tuned. Studies have shown that a poorly tuned engine can increase fuel consumption by as much as 10 to 20 percent depending on a car's condition. Follow the recommended maintenance schedule in your owner's manual; you'll save fuel and your car will run better and last longer.
• Keep your tires properly inflated and aligned. Car manufacturers must place a label in the car stating the correct tire pressure. The label usually is on the edge of the door or door jamb, in the glove box, or on the inside of the gas cap cover. If the label lists a psi (pounds per square inch) range, use the higher number to maximize your fuel efficiency. Underinflated tires cause fuel consumption to increase by six percent.
• Change your oil. Clean oil reduces wear caused by friction between moving parts and removes harmful substances from the engine. Change your oil as recommended by the vehicle manufacturer.
• Check and replace air filters regularly. Your car's air filter keeps impurities in the air from damaging internal engine components. Not only will replacing a dirty air filter improve your fuel economy, it also will protect your engine. Clogged filters can cause up to a 10 percent increase in fuel consumption.
• Consider buying a fuel efficient vehicle. Deciding which vehicle to buy may be the most important fuel economy decision you make. The difference between a car that gets 20 MPG (miles per gallon) and one that gets 30 MPG amounts to $3,125 over 5 years, assuming gas costs $2.50 per gallon and you drive 15,000 miles a year.

Efforts

The EPA evaluates or tests products to determine whether their use will result in any significant improvement or detriment to fuel economy. However, the EPA cannot say what effect gas-saving products will have on a vehicle over time because it hasn't conducted any durability tests. It's possible that some products may harm the car or may otherwise adversely affect its performance. In fact, today's vehicles' emission control systems are very sophisticated and complex. They have On Board Diagnostic features that alert the driver to problems associated with the emission control and fuel delivery systems. Retrofit products may have an adverse effect on these systems.

Devices Tested

The following list categorizes various types of "gas-saving" products, explains how they're used and gives product names. Those with asterisks may save measurable, but small, amounts of gas. All others have been found not to increase fuel economy.

Air Bleed Devices. These devices bleed air into the carburetor. They usually are installed in the Positive Crankcase Ventilation line or as a replacement for idle-mixture screws.

Vapor Bleed Devices. These devices are similar to the air bleed devices, except that induced air is bubbled through a container of a water and anti-freeze mixture, usually located in the engine compartment.

Liquid Injection. These products add liquid into the fuel/air intake system and not directly into the combustion chamber.

Ignition Devices. These devices are attached to the ignition system or are used to replace original equipment or parts.

Fuel Line Devices (heaters or coolers). These devices heat the fuel before it enters the carburetor. Usually, the fuel is heated by the engine coolant or by the exhaust or electrical system.

Fuel Line Devices (magnets). These magnetic devices, clamped to the outside of the fuel line or installed in the fuel line, claim to change the molecular structure of gasoline.

Fuel Line Devices (metallic). Typically, these devices contain several dissimilar metals that are installed in the fuel line, supposedly causing ionization of the fuel.

Mixture Enhancers (under the carburetor). These devices are mounted between the carburetor and intake manifold and supposedly enhance the mixing or vaporization of the air/fuel mixture.

Mixture Enhancers (others). These devices make some general modifications to the vehicle intake system.

Internal Engine Modifications. These devices make physical or mechanical function changes to the engine.

Accessory Drive Modifiers. These devices reduce power to specific auto accessories.

Fuels and Fuel Additives. These materials are added to the gas tank.

Oils and Oil Additives. Usually these materials are poured into the crankcase.

Driving Habit Modifiers. These are lights or sound devices to tell the driver to reduce acceleration or to shift gears.

Car Sharing

The primacy of car-based mobility has become a widespread problem in most cities in the world. In Australia, the situation is no different, as the car has an even more dominant role than in European cities. In most of the countries, transport is the fastest growing sector contributing to greenhouse gas emissions. Emissions from transport are second in magnitude only to the stationary energy sector. Enormous amounts of land and capital are bound up with cars, roads and parking space. This is a result of high levels of private car ownership. Although in medium and high-density urban areas many people walk, cycle and use public transport, there are occasions when they still see a need for some car travel. This is the 'mobility gap' that car sharing seeks to all.


This report describes the concept of car sharing. Its purpose is to identify car sharing organisations in other countries and to examine the preconditions required to establish and run a car sharing organisation (CSO) in order to examine the countries conditions as a basis on which to encourage local initiatives. At an anecdotal level, car sharing is known to exist in a number of cities. For example, approval was granted to a high-rise residential development to operate a car sharing scheme through a local car provider as a substitute for not providing on-site car parking. Other CSOs are small-scale and none is known to be linked formally to public transport providers.

Car sharing is one of a number of mobility strategies, which solves some car ownership problems and problems associated with high car-reliance.

In the primary layer, individuals gain the benefits of private cars without the costs and responsibilities of ownership. Specifically, car sharing allows a member (such as a household or business) to access a meet of shared cars and other types of motor vehicles as needed, paying a usage fee each time. This removes high fixed costs such as registration and third-party insurance, as most costs become both variable and lower. Vehicles are available to members more or less as required for any length of time (from one hour, up to several weeks or more) and at many points (dozens of locations in a city or even in other cities). So, instead of buying a car, people and/or companies, share a meet of vehicles with usage costs dependent on the kilometres travelled and the period of time for which the vehicle is booked. In the second layer, car sharing helps the community reduce the number of trips and distances travelled by private cars. In the third layer, urban communities gain space for productive uses when space currently occupied by roads and parking is not expanded and communities also experience less air and noise pollution.


Car sharing should not be confused with car pooling, which is more accurately termed 'ride-sharing'. In car pooling, owners of cars provide rides to other passengers in a more or less organized way, on a regular or irregular basis. It requires mutual agreement and trust and is generally not suitable for organising as a for-profit business.

The opportunity remains, however, to systematically develop appropriate indicators and an agreed methodology to compare different car sharing schemes.

Some potential indicators include:

• number of vehicles/members (total members)
• reduction in private motor vehicle kilometres travelled (VKT)
• CO2 emissions reduced
• number of cars replaced
• increase in public transport use
• increased time walking and cycling
• area/kerbside distance of parking saved with opportunity for improved re-use, e.g. as dedicated cycleway, parkland and/or open space
• more affordable housing or other savings in developments, e.g. saving space and costs of parking and improving amenity.

Benefits to individuals involved in car sharing :

The following are some of the key reasons individuals may choose to be involved in a car sharing organization:

• Economic : significant reduction of costs as opposed to owning a motor vehicle, including no need for private parking space and the opportunity to redeploy household expenditure that would typically have been devoted to the sunk costs associated with motor vehicle ownership.
• Convenience : no administrative effort or time expenditure on insurance, purchase and sale, repairs, permits etc.
• Improved access: enhanced mobility options, including access to multiple types of vehicle resulting in a choice of the most economically sensible transport mode.

CAFE

Corporate Average Fuel Economy (CAFE) is the sales weighted average fuel economy, expressed in miles per gallon (mpg), of a manufacturer's fleet of passenger cars or light trucks with a gross vehicle weight rating (GVWR) of 8,500 lbs. or less, manufactured for sale in the United States, for any given model year. Fuel economy is defined as the average mileage traveled by an automobile per gallon of gasoline (or equivalent amount of other fuel) consumed as measured in accordance with the testing and evaluation protocol set forth by the Environmental Protection Agency (EPA).

The Secretary of Transportation has delegated authority to establish CAFE standards to the Administrator of the National Highway Traffic Safety Administration (NHTSA). NHTSA is responsible for establishing and amending the CAFE standards; promulgating regulations concerning CAFE procedures, definitions and reports; considering petitions for exemption from standards for low volume manufacturers and establishing unique standards for them; enforcing fuel economy standards and regulations; responding to petitions concerning domestic production by foreign manufacturers and all other aspects of CAFE, including the classification of vehicle lines as either cars or trucks; collecting, recording and cataloging Pre- and Mid-model year reports; adjudicating carry back credit plans; and providing program incentives such as credits for alternative fueled vehicle lines.

EPA is responsible for calculating the average fuel economy for each manufacturer. CAFE certification is done either one of two ways:

1) The manufacturer provides its own fuel economy test data,
2) the EPA will obtain a vehicle and test it in its Office of Transportation & Air Quality facility in Ann Arbor, MI.

EPA will do actual tests on typically about 30% of the existing vehicle lines, using the same laboratory test that they use to measure exhaust emissions. The entire certification test procedure, including the vehicle test preparation, the actual running of the test on the dynamometer, the recording of the data, etc.

Congress specified that CAFE standards must be set at the "maximum feasible level". Congress provided that the Department's determinations of maximum feasible level be made in consideration of four factors:

(1) Technological feasibility;
(2) Economic practicability;
(3) Effect of other standards on fuel economy; and
(4) Need of the nation to conserve energy

Manufacturers can earn CAFE "credits" to offset deficiencies in their CAFE performances. Specifically, when the average fuel economy of either the passenger car or light truck fleet for a particular model year exceeds the established standard, the manufacturer earns credits. The amount of credit a manufacturer earns is determined by multiplying the tenths of a mile per gallon that the manufacturer exceeded the CAFE standard in that model year by the amount of vehicles they manufactured in that model year. These credits can be applied to any three consecutive model years immediately prior to or subsequent to the model year in which the credits are earned. The credits earned and applied to the model years prior to the model year for which the credits are earned are termed "carry back" credits, while those applied to model years subsequent to the model year in which the credits are earned are known as "carry forward" credits. Failure to exercise carry forward credits within the three years immediately following the year in which they are earned will result in the forfeiture of those credits. Credits cannot be passed between manufacturers or between fleets, e.g., from domestic passenger cars to light trucks.

Authority to establish vehicle classifications for the purposes of calculating CAFE was delegated to NHTSA. Specifically, the definitions are as follows:

1. Passenger Car – any 4-wheel vehicle not designed for off-road use that is manufactured primarily for use in transporting 10 people or less.

2. Truck – A vehicle can be classified as a truck if it meets one of the following criteria:

• It is 4-wheel drive or it is rated at 6,000 pounds gross vehicle weight AND has at least four of the following characteristics:

1. Approach angle of not less than 28 degrees
2. Breakover angle of not less than 14 degrees
3. Departure angle of not less than 20 degrees
4. Running clearance of not less than 20 centimeters
5. Front and read axle clearances of not less than 18 centimeters each

• It can perform at least one of the following functions:

1. Transport more than 10 people;
2. Provide temporary living quarters;
3. Transport property in an open bed;
4. Permit greater cargo-carrying capacity than passenger-carrying volume;
5. Can be converted to an open bed vehicle by removal of rear seats to form a flat continuous floor with the use of simple tools.

Tips for greener motoring

Your driving habits, the type of vehicle you drive and the conditions under which you drive will affect your vehicle's environmental performance. Follow these tips for greener driving.

Minimize your vehicle use :
Think about your travel needs prior to your travel. Planned travel decisions will result in fewer trips and more efficient/cheaper travel than unplanned decisions made 'on the go'. Some travel planning tips:

• Plan to do a number of errands in one trip rather than several trips and save both time and fuel (for the first couple of minutes of a car trip the engine is cold and this results in an increase in fuel consumption per kilometer).
• Patronize shops near to you whenever possible to reduce the distances you travel by car. Walk or cycle to your local shops if you can.
• Avoid peak-hour traffic whenever possible.
• Use alternative transport, eg. public transport (bus, train, tram or ferry), walking or cycling. These alternative methods of travel are often cheaper, and may provide other benefits including increased fitness.

Drive in high gear :
The engine runs most efficiently between around 1,500 and 2,500 rpm (lower in diesels). To maintain these low revs you should change up through the gears as soon as practical and before the revs reach 2,500 rpm. Automatic transmissions will shift up more quickly and smoothly if you ease back slightly on the accelerator once the car gathers momentum.

Drive smoothly - avoid unnecessary acceleration :
Drive at a good distance from the car in front so you can anticipate and travel with the flow of traffic. You will be able to see such things as traffic lights changing or cars turning and minimise your fuel use through braking and accelerating back up to full speed.

Minimize fuel wasted in idling :
Minimize fuel wasted in idling by stopping the engine whenever your car is stopped or held up for an extended period of time. By having the engine switched off, even for a short period, you will save more fuel than is lost from the burst of fuel involved in restarting the engine. The net increased wear and tear from this practice is negligible.

Speed kills economy :
High speeds result in high fuel consumption. At 110 km/h your car can use up to 25% more fuel than it would cruising at 90 km/h.

Minimize aerodynamic drag :
Additional parts on the exterior of a vehicle such as roof racks and spoilers, or having the window open, increases air resistance and fuel consumption, in some cases by over 20%.

Look after your vehicle's tyres :
Inflate your vehicle's tyres to the highest pressure recommended by the tyre manufacturer and make sure your wheels are properly aligned (remember to keep your spare tire inflated as well). Looking after your tyres will not only reduce your fuel consumption it will also extend tyre life and improve handling.

Use air conditioning sparingly :
Air conditioners can use extra fuel when operating. However, at speeds of over 80 km/h, the use of air conditioning is better for fuel consumption than an open window.

Travel light :
Don't carry more people or cargo than you have to. The more a vehicle carries the more fuel it uses; an extra 50kg of weight can increase your fuel bill by around 2%.
Service your vehicle regularly

Keeping your vehicle well tuned will minimize its environmental impact.