Scandinavian research finds that in many cases, where you think you might be helping the environment with your ‘clean’ car, you could be damaging it in other ways you’ve not considered.
It all comes down to measurement again – how do you measure the eco-impact of an engine and its fuel? Miles-per-gallon? Carbon footprint?
Well Høyer and Holden concluded that if you try to save in one area, such as CO2 or miles per gallon, you lose out somewhere else:
“It must be emphasised that no single chain comes out with the best score on all impact categories. There are always trade-offs involved. Thus, there are no obvious winners; only good or bad trade-offs between different impact categories.”
Interestingly, they found petrol cars and hybrid-petrol to be the worst in terms of CO2 emissions and fuel efficiency. The natural gas-based hydrogen fuel-cell option, on the other hand, came top of the list.
“We have to move quite far down the list [of fuels] to meet the first renewable alternative: biological methanol applied in fuel cell vehicles.”