How 'tiny steps' will improve on record 141.2mpg
The man responsible for the diesel engine that returned a phenomenal 141.2mpg says they still have room to improve.
But it will be through 'tiny steps, tiny steps' Francois Galliot, chief engineer 1.6BlueHDI told me in Graz, Austria.
And it very well may be that the next family of Blue HDi technology engines will be part of a 'light hybrid' system (alternators can help deliver an electric boost, for example).
That would mean still leaner diesels with overall consumption, and consequently emissions, being helped by an electric source.
He laughed when I asked him how long it would take for another significant increase in the number of kilometres a car could cover on a litre of fuel.
"Tiny steps," he courteously admonished as I attempted to reflect in my questions the high level of interest coming into Motors from readers.
For now, he said, the cost of developing the acclaimed 1.6-litre diesel has to be recouped.
That is before the following generation - to meet the next set of emissions regulations within a short few years - evolves and develops.
Msr Francois was responding to my queries about just how much more can be extracted from the internal combustion engine.
He reflected that what we will call the '141mpg engine' represented a significant advance (8pc) on what was their previous best,
But such a leap of achievement is unlikely to be repeated - hence his assessment that it will be 'tiny steps'.
He explained, in great detail, how they achieved the 141.2mpg. And that included getting right down to minute examination of the average 56kmh speed which, he revealed, was the optimum to get maximum return on the Peugeot 208 hatchback used for the test.
Just to remind you, the standard production 208 had the 1.6-litre BlueHDi 100 Stop/Start engine under the bonnet and an ordinary 5spd manual gearbox.
It covered 1,337.19 miles (2,152kms) on 9.45 gallons (43 litres) of fuel - 2litres/100km.
That is the equivalent of five Dublin/Galway round trips.
That's a lot of 'tiny steps'.
And no I didn't get anything like 141mpg when I drove it last week.