Re-reading the 20mph city article (The Argus, June 15), I see that there’s a sentence suggesting pollution may be reduced. How might that be?

At 30mph, I can drive my car comfortably in fourth gear, with the engine running at about 1300rpm and a feather-light touch on the throttle. At 20mph the car has to be in third gear, with a greater throttle pressure and an engine speed of 1400rpm. That’s an increase in emissions of about 10%.

But that’s only part of the story, of course. Travelling at 20mph instead of 30mph, I’ll be pushing out those extra emissions for 50% longer.

I reckon that’s a total increase in emissions of around 60% in my case, and I doubt if my car is much different to many others. I can recall an Argus headline of not so long ago, bemoaning the fact that Brighton was being choked by traffic fumes, yet lower speed limits look certain to make things worse.

Whilst any effort to reduce road deaths is laudable in itself, I have to wonder if the blanket 20mph speed limit is the right way to go about it.

Just how much future trouble might we be stoking up in lung-related illness and possible resultant deaths?

Andy Gilbert
Tarring Close, Newhaven