Quote Originally Posted by Rjk View Post
there is less pollution per journey at 20 compared to 30
How do you work that out? Car revs are roughly the same using 3rd at 20mph as 4th gear at 30mph. I find I switch down more to 2nd gear at 20mph, meaning higher revs and using more fuel.

A regular journey of mine has taken me 5 minutes longer both yesterday and today. I reckon that if I'm driving for 5 minutes more I'm using more fuel and creating more pollution.