On Sunday, 11 March 2018 01:09:16 UTC, Bill wrote:
In message , "Dave Plowman (News)"
writes
In article ,
tabbypurr wrote:

Hybrid technology gets round the problem of poor efficiency in stop start
conditions.

does it? The Toyota Priapus gets worse combined cycle mpg than a
straight engine.

You don't seriously believe official tests?

All hybrids do well in stop start conditions. The whole reason for them.
They're totally pointless at cruise.

I have no experience with hybrids, but something with a reasonable sized
battery and on-board diesel engine to charge it seems possible way to
go. The diesel could perhaps be designed to run at a constant maximum
efficiency and have appropriate cleaning add-ons if necessary.

At max efficiency it's far from max output, so the engine would have to be excessively large. Everything in car design is compromises & tradeoffs.

All I know is that my diesel vehicles use massively less fuel under
long-stop start conditions than any petrol vehicles I've had. It's a
huge difference and I do wonder what the petrol engines were throwing
out in the way of un or partly burnt fuel when cold.

Lower compression is the problem with petrol, it means less of the motive energy is harvested.

The evidence seems to be that particulates are mainly from tyres, brakes
etc. and these are about 10 times the quantity produced by engines.

It seems to me that many people, even the ones here, are gradually being
brainwashed by the drip of anti-diesel propaganda, much of which seems
based on hearsay.

interesting how we don't hear more about tyre particulates.

When a town near me bans or charges for diesels, I will simply never go
or spend money there again. Shame about the shops and businesses, but my
policy has worked with parking charges, and has been adopted by others
judging by the increasingly ghostly local shopping areas.

Sadly councils show no sign of learning from such cockups. That's the problem with putting people in charge that pay no price for screw ups.

Petrol, diesel & hybrid technologies are all much improving. To act heavy handedly against any one of them merely wipes out a large chance for a better future. So that's what politicians will do.


NT