"David Spiro" wrote in message
...
"Martin Underwood" wrote in message
...
Certainly the high fuel prices in Britain (and to a lesser extent in the
rest of Europe) have been the reason for the smaller proportion of cars
with
automatic transmission (less fuel-efficient) and the higher proportion of
cars with diesel engines (more fuel-efficient) than in the US.

I agree that diesel is more fuel efficient, but, IIRC, it also tends to be
more of a pollutant that regular gasoline. Has there been any improvement
in
Europe in combating this problem?

A lot of modern diesel cars have "particulate filters" which trap the PM10
carbon particles and then burn them to produce CO2 which may fuel the
greenhouse effect but at least don't cause asthma. Unfortunately my car is a
couple of years too old to have a particulate filter. However I think the
design of modern diesel engines, especially those with very high-pressure
direct injection, burns the fuel more completely, leading to greater power /
lower fuel usage and also less PM10 emission. The one thing we've not seen
much in the UK is bio diesel - produced from biological sources such as rape
seed - or recycled diesel which processes waste cooking oil to produce
diesel. For some reason, the rises in the price of fuel over the past few
months have affected diesel prices more than petrol: going back a few years,
diesel used to be slightly cheaper than petrol, then it drew level and
became 1-2 pence/litre more expensive, but stilll cheaper than leaded or
lead-replacement petrol; now it's consistently the most expensive fuel on
the forecourt, typically 5 pence/litre more than unleaded. Since the fuel
duty (a fixed rate that's not dependent on the raw material cost) hasn't
changed, I'm not sure what's happened.

Still, as long as my trusty Peugeot continues to do 50 miles/gallon (that's
about 40 miles per US gallon), I'm happy. At the time of the fuel strikes in
2000, I was commuting about 90 miles a day until I moved closer to where I
work and a colleague was doing a similar distance. The difference was, my
car did 50 mpg and had a range of about 650 miles between fillings, whereas
he had an imported Buick or Cadillac which did about 15 mpg. Many people
(such as him) were having to take days of work because they were about to
run out of fuel and even the trains and buses were cutting their services to
conserve fuel, whereas I managed (just) to find sufficent garages that were
open so I could keep going.

The fuel strikes actually raised an interesting legal issue: diesel for
off-road use (eg heating oil, generators, farm vehicles etc) is taxed at a
much lower rate. It is dyed red to distinguish it from DERV (diesel engined
road vehicle) diesel, and it is a serious offence to use red diesel in cars
and lorries. At the time of the strikes, these rules were relaxed because
fuel was in such short supply and you were allowed to use red diesel if you
could find it. The red dye stains the parts of the engine - even if the
police don't find red fuel in the tank, they can still (in extreme cases)
take the engine apart to look for tell-tale staining. But once you allow
cars to use red diesel legally for a while, you can't rely on that ever
again to prove whether a car has been illegally using red diesel - anyone
caught (as long as they don't actually have the fuel in the tank) can say
"oh, that's from when I was allowed to use it during the fuel strike".

As for automatic transmissions, they are
better at being fuel efficient on the highway, if there is a c"cruise
control" feature built in. (Which has become almost standard here in the
U.S.) While this feature is primarily for highway driving, it allows the
vehicle to go at a constant speed for longer periods of time, and in my
experience, has been able to inprove fuel efficency at least at highway
speeds. Automatics are probably less fuel efficent in city driving though,
and of that, I have no doubt.

Ring road? Is that the M25? (Same as the North Circular you mentioned?)I
seem to remember driving on that at some point. I hear that is a bitch of
a
road to use.

There are two ring roads around London. The M25 motorway is roughly 15-20
miles away from the centre of London. It's at least 3-lane and in the
busiest section to the south-west of London it's 4-lane. However it's become
a victim of its own success: so much traffic uses it that in busy periods it
becomes clogged with traffic so you need to drive slower - in fact many
sections have variable speed limits which come into force to slow traffic
down when it gets busy. Since these are stringently enforced, you get the
absurd situation of 4 lanes of traffic all doing 50.0 mph with one lane not
moving relative to another, which makes it virtually impossible to move to
Lane 1 when you want to leave the motorway; many times I've stayed in Lane 1
if I'm only going a few junctions because before now I've got trapped in a
further-right lane with no-one letting me in (even though I indicate a mile
before the junction) to start moving left to exit. Also, at busy periods,
people think the laws of physics don't apply and don't leave enough stopping
distance between them and the car in front: if you leave a sensible space,
someone nips in and you have to brake to re-create a gap which someone then
takes - and so on ad infinitum.

Then there's the North- and South-Circular roads (A406 and A205
respectively) which are about 5-10 miles from the centre and consist of what
used to be ordinary single-carriageway roads which have been widened in
places where there's space but in other places remain one lane in each
direction (the notorious Hanger Lane section between the M4 and the M40
springs to mind) so that too gets very congested and leads to
bumper-to-bumper stop-start traffic jams. It also has frequent traffic light
junctions which further slow the traffic down.

When I was going to London I went straight through the middle; when I was
coming back I went via the North Circular which was a good 20 miles further
and didn't seem to take any less time because of avoiding the city centre.
My experience with driving in London is that in the centre it's very busy
but traffic keeps moving - sometimes you can reach 30, a lot of the time
your at about 20, but as long as you look a long way ahead and don't get
stuck behind a row of parked cars in the left lane, waiting till some kind
person lets you pull out, then you keep moving. The worse congestion is in
the suburbs a few miles out of the centre (Shepherd's Bush, Willesden,
Streatham etc) where even in quiet times you usually end up stationary for
fairly long periods of time. I've not driven in London since the Congestion
Charge was introduced, so I don't know whether it's led to an increase of
traffic on the roads just outside the zone which are diverting to avoid
paying the charge.