Are diesel’s days numbered? This has been the question that people have been asking in the last few weeks since the Volkswagen scandal. People in Europe (not the US sales are very low there) were persuaded to buy diesel cars for a couple of reasons. Lower CO2 emissions and much better economy. These were reinforced by tax breaks on the fuel. Essentially what happened is this; the French government decided to support its carmakers by getting then to develop diesel cars after the first oil crisis. The same thing happened in the US but after some real clunkers America gave up (which affects US thinking on diesel cars until today). The French and then other European manufacturers persevered. The early models were poor, I remember as a child a friends mother giving me a lift home in French one. We had to sit in the snow for 5 minutes while the fuel warmed up. It was also difficult to buy diesel fuel, only filling stations used by trucks sold it.
However, in recent years the technology has improved. Glowplugs mean no waiting for warmup, turbochargers mean its not like driving a taxi and diesel fuel is available everywhere. There is just one problem NOx (nitrogen oxides). Nitrogen gas is a triple bonded molecule formed of two nitrogen atoms. Breaking it takes a lot of energy, combustion supplies that energy and for some reason diesel cars produce more NOx than petrol cars. NOx forms acid rain, exacerbates asthma and other lung pathologies and causes stomach cancer. Its also a greenhouse gas.
We like many others switched to diesel for the reasons above, but have recently switched back (before all this broke so for unrelated reasons). I miss the power of the diesel car, which always had grunt however loaded up and its economy. Our petrol car is a bit underpowered and needs a larger engine (sometimes lack of power this is dangerous – I’m not a speed freak). However I’m glad we switched. Whilst it looked like petrol cars were going the way of the dodo round here I have read today (completely coincidently apparently) that car manufacturers have been working on petrol cars. There are now models coming out with turbochargers (ironic since they were developed for petrol) and achieve 100mpg, in the same range as diesel cars.
Of course a couple of things need to be said. First, however economical our cars are we need to cut down on their use for reasons regular readers of this site will be familiar with. Second, there is at least a possibility that real world data may have been doctored and these cars are not as good in real life as they are made out. Nevertheless the fact that manufacturers are working on petrol models and they are getting “greener” is encouraging.