Reducing the speed of a typical car from 30 mph to 20 mph decreases its mpg by 35%
Having lived in London since I was 6, I have lost a significant fraction of my life to politicised road regulation. This state control ideology endeavours to force us all onto public transport rather than into privately owned vehicles: “You will own nothing and be happy” was not invented by Klaus Schwab.
It is way past time for the absurdity of UK road regulation to be exposed for the scam, for the fraud, for the toxic and destructive racket, that it truly is. And it is my great pleasure to have a part in that Exposé. So on behalf of the drivers of this Great Great United Kingdom with the richest and most diverse culture in the entire world, together with the most incompetent ascientific arrogant ossified and destructive bureaucracy in the West – here goes…
Cars are at their most efficient and therefore their least polluting (best mpg) when they are running at around 40-45 mph. They are less efficient, more polluting, more carbon burning (lower mpg) at 20 mph than they are a 30 mph. Therefore reducing the speed limits in cities from 30 to 20 causes more pollution and obviously more congestion since each car spends a longer period of time on the roads.
Here are the figures for a 1986 VW Golf GTi noting the gear changes. The GTi achieves 40 mpg at 30 mph and 30 mpg at 20 mph a reduction of 25% in fuel efficiency caused by the 20 mph speed limit.
Here are some examples from a graphic found on Google images sourced from David Miller on Quora. They show the Honda Civic (which is close to the average in the comparison) achieving 33 mpg at 30 mph and 23 mpg at 20 mph. This is a reduction of 30% in fuel efficiency caused by the 20 mph speed limit.
Read More: ULEZ: The 20 mph speed limits INCREASE pollution by 35%