Prius secundus

Bit of a hybrid vehicle theme this week...

I had known there was a Toyota Prius serving as a taxi in Bath but was confused; sometimes it appeared to have 2006 plates; sometimes 2008. Then, for the first time I saw the two together here in the Orangery, in the centre of Bath (the tower of Bath Abbey is hidden by the natural foliage and the Guildhall appears to have acquired some artificial foliage).

To make the distinction easier, one taxi driver had helpfully acquired a dent in his vehicle's front nearside wing.

One thing I like about the Prius and similar cars is that their computers switch off their petrol engines when they're not needed. Some non-hybrids now do that too, though the hybrid is also able to move off using battery power instead of re-starting the engine (and of course fully electric vehicles have no internal combustion engine to start up at all).

So when a hybrid queues in urban congestion, as like as not its engine is switched off, reducing traffic fumes and particulate emissions significantly. And you can smell the difference in town.

I would rather local councils mandated taxis be replaced by hybrid vehicles when they grow too old to serve than, for instance, insisting that all local taxis be painted black - or blue.

Taxi, van and bus drivers are notorious for leaving their diesel engines idling while waiting for fares, delivering, etc. Any engineer will tell you an idling engine is running inefficiently compared to one delivering its optimal power, and therefore is relatively more polluting than might be expected going by its fuel consumption alone.

If we cannot learn good practice (as is enforced by those Little Old Ladies in Black Widows' Weeds who leap out at you if you leave your engine running at Swiss traffic lights) then perhaps a technological solution to the problem of unnecessary emissions is secundus best.