New quiet lifters,
AO Silver Member
Join Date: Feb 2012
Location: United Kingdom
County: Greater London
It's complicated. There's a large carbon and energy cost from producing any new car, including EV. Estimates vary but most assess manufacture as half of the lifetime cost, with the fuel used accounting for the other half including the carbon cost of extracting, manufacturing, infrastructure and transport of the fuel itself.
EV's are not that different. The carbon and energy cost of manufacture is similar, and can be higher. The carbon cost of electricity production and delivery is very variable. BEV shows a net advantage over a comparable ICV within 3 years, in California where nearly all generation if from renewables, mostly solar. In US states with more mixed generation, it takes 5 years or so, but in some states where coal and oil are the main fuels, the BEV will take more than the likely life of the vehicle before it becomes 'cleaner'.
The UK's current (sorry!) mix of gas, nuclear, oil, wind, hydro probably puts BEV in front by the time it's 5-6 years years old.
BUT scrapping perfectly usable vehicles, whose carbon cost of production has already been amortised, in order to build new ones that incur a whole new cost but are net only marginally cleaner, is really silly. Unless you're a manufacturer, or a government wanting to support the industry, eg the scrappage scheme of the GFC period, when they advised everybody to buy diesel because the greater fuel efficiency produced lower CO2.
It's pretty funny to see that is now old hat, and diesel is the pariah fuel, so we should all buy small, lean-burn direct-injected, turbo petrols. They approach the fuel efficiency of diesel. They also produce more PM and NOx, because of the higher combustion temps. So EGR and, now, particulate filters are appearing on petrol. It's almost as if there is no such thing as a free lunch... Personally even if I could, I wouldn't buy a new car. It's a racing certainty government will change its advice, destroy residual values prematurely, and tax the crap out of small, lean-burn, direct-injection turbo petrols as soon as the industry needs another leg-up.
I know this is cynical, but DEFRA's own air quality survey shows that even if every single petrol and diesel car, bus, lorry and motorcycle was banned and crushed, we'd only see 18% less CO2, NOx and PM. Actually not even that, the recycling would use colossal amounts of energy. Keeping existing vehicles running and using them as little as possible, is the best way to reduce emissions. All those folk with Bussos that they can't afford to use much are in fact saving the planet.
Last edited by halftone; 26-05-19 at 08:34.