Old, old news.
That the "EU Mandated" tests are virtually meaningless as a measure of polution and CO2 has been known by analytical chemists and engineers for years.
Taxing cars on CO2 output measured by these tests is totally unfair. Which is why the new UK car tax system is good.
The only value the standard tests have is to allow a crude comparison between vehicles, but even that is risky.
Internal combustion engine burn hydrocarbons which produce CO2 and other pollutants. Petrol engines are cleaner than diesel, but not as efficient at burning fuel. Because turbo diesels burn at high temperature and pressure they are more efficient, but produce oxides of nitrogen, which are hard to remove. There are no easy answers.
Short term small petrol engined hybrid motors are a good substitute for diesel, but they still burn hydrocarbons and I'm not convinced batteries are green enough through their product lifecycle.
Hydrogen power, anyone?
