On 23/10/2012 19:56, Dave Liquorice wrote:
On Tue, 23 Oct 2012 16:58:54 +0100, Arfa Daily wrote:

They said that it was called an "Eco-trailer" because being some 2
metres longer than a standard' trailer, it would be able to carry nine
more cages of Tesco goods, which would mean less lorries on the road
leading to a fuel and pollution saving.
snip
I started to think about the 'not getting owt for nowt' principle, and
started to doubt whether there really is any 'free lunch' to be had
here.

Very wise, and you highlight a lot of the variables that come into play.

I know that diesels aren't the cleanest of engines, but as far as
I am aware, they produce little or no carbon dioxide,

Er no, burning a carbon based fuel like diesel produces mostly CO2 and
H2O...

so is this just another case of adding the word "Eco" to the front
of some existing item, to justify getting what might be a contentious
change to that item, accepted ?

Possibly. I would expect the truck maker to have the official MPG figures
for that model on their website(*). IMHO what really matters is how much
is delivered for how much fuel consumed

Or am I just being cynical in thinking that if Stobarts got the
approval to roll this out across their fleet of curtain-siders, they
would save the wages of one sixth of their drivers ...

The might be able to reduce the work force a little but these big trucks
won't be able to get everywhere. Some places there is no access for even
a "standard" acrtic...

I suspect the drivers wages are small in comparison to the trucks fuel
bill. Lets say 10mpg (real mpg is probably lower) 1 hour at 56 mph is 5.6
gallons @ £6.30/gallon about £35/hour. I'd expect the drivers to get less
than half that rate, may be less than 1/3.

If you can deliver 20% more for the same fuel costs or even 20% more
goods for 15% more fuel it would still be "green"...

(*) Can't find it with a quick google. But didi find and interesting
document "EFFECTS OF PAYLOAD ON THE FUEL CONSUMPTION OF TRUCKS". That
gives a range fro about 15 mpg down to 6 mpg, unladen to fully laden.

If they end up needing to send smaller trucks to some locations, that
also needs to be factored into the overall "savings". Ah! - the ten
stores we deliver to saves 10% but the extra one we can't get into needs
a special trip by a lorry for that place only - which wipes out all savings.

--
Rod