Some of the new engine complexity involves emission control systems that require electronic monitoring and adjustment of engine performance under different operating conditions. Several devices are added to the engine to handle air flow in, fuel delivery and exhaust out. Computers have been added to monitor and control engine performance. Most car engines designed after 1996 have a standard port that allows a diagnostic computer access to information about engine performance.
Driving a car is the most polluting act an average citizen commits. Emissions from passenger vehicles are increasing in Canada and the US despite attempts to make engines more fuel efficient and despite the addition of antipollution devices. The two main reasons are: 1. vehicle use has increased; 2. cars were getting bigger and pick-up trucks, vans and sports vehicles often replaced smaller, lighter passenger cars.
The average new vehicle in 2003 consumed more fuel that its counterpart in 1988. In the USA in 1987 cars averaged 25.9 miles to the gallon. Fuel efficiency dropped to 24.6 miles/gallon by 1998 and is dropping further as larger vehicles replace smaller ones.
Despite scientific evidence of climate change, governments in most affluent countries have avoided their responsibility to reduce emissions of greenhouse gases. The USA is the biggest emitter of greenhouse gases