A Comfortable Car & Cheap To Run

in Guy King

Lol. Fair enough.
I'm unclear about exactly what point 'slow' becomes 'gentle', so if that
happens at the point of best economy, then I retract what I said

 

In message <m9Hoe.2261$>

Well, the instantaneous readout on the trip computer certainly gives
that impression. Fuel consumption jumps up to 999mpg.

And the 407 is a heavy car. But I understand that the new Passat will
be even heavier.

More apparent on some cars than others. My old 306 XUD 1.9 didn't
seen anything like so sensitive to driving style. Nor, I am told, is
the 130 pd powered Passat. My colleague with a Passat claims that he
gets consistent mpg almost indenpendent of driving conditions and
style.

Good. I haven't done 3000 miles yet, and I am already seeing
spectacular improvements. I was disappointed at first as you may have
gathered.

I hadn't expected this. Peugeot say that the engine doesn't need
running in because it has been "bench run". I'm, happy to be proved
wrong.

But for a heavier vehicle, I would expect the effect to be more
noticable. It takes more energy to accelerate a larger mass, as
Newton showed.

I have occasionally turned off the dual zone climate control in the
407. But never for long enough to see its effects on fuel
consumption. But presumably with climate control, more fuel will be
used in hot weather, when cooling is needed. This has only been
necessary in the last 3 weeks or so. And as I said, consumption is
getting better rather than worse.

Martin

 

In message <42a36164$0$25424$>

You could have fooled me. I doesn't feel like it. It doesn't look
like it either.

 

They're right in that it doesn't *need* running in - ie, you don't need to
keep below 3000rpm in the first 1000 miles etc.

But as you cover more miles, things will loosen up as the friction surfaces
wear etc. - note that as you cover more miles, this trend will reverse.
You'll make less power and give less economy when you're upto 150,000 miles

 

150k? Bah. That's barely run in for a PSA TD/HDi lump!

 

Martin Dixon wrote:

[...]

Friend of mine just did a return trip Rosyth - Rotterdam - 'Ring in a
chipped 330d with 280bhp at an average of 37mpg /including/ five laps of
the 'Ring (9'55" best lap) and cruising at ~120-150mph through most of
Germany...

Jings!



A

 

In message <[email protected]>

Well, what I meant is not flooring the accelerator or revving the
engine unduly. Changing up early. Avoid braking as much as possible
by anticipating when you will need to slow down, bearing in mind that
in 6th grear a 407 loses speed very slowly indeed, or not at all on
even a slight downhill slope. With the 407 i can keep below 2000 RPM
all the time for example, if I drive within the legal limit.

It doesn't mean driving slowly at all, within reason. 2000 RPM is
peak torque, so you can still accelerate well when you need to.

Martin

 

That's because it's almost certainly still squirting in a meaningful amount
of fuel into the engine. It's only because of tall gearing that it does
this...

With the air conditioning system compressor running, most ECUs* continue to
squirt fuel into the donk, so you can extend your deceleration distance over
a considerable distance.

The technique is the same for all cars, it just feels easier in some. With
ours, we don't have such tall gearing but I can achieve the same effect as
you by giving the engine a bare sniff of power, thus extending my
deceleration over a considerable distance. It achieves the same thing. You
just have to think about it more.

*in my experience at least.