Hi all,
I have just registered to help on this question.
This is the kind of discussion that often irritates me.
So many factors but mostly it is the quality of the driver these days !
One place you can find some hard numbers on any car is here :
https://www.spritmonitor.de/en/overview ... owerunit=2
On this site many car owners religously enter fuel used at each tank and record over time.
I have been doing this for decades and many of my cars are here. Many of the "best owners"
(the most frugal) see this as a challenge to get the best numbers. So many cars and engines
it really gives you an idea of what can be achieved before buying (new or used).
I have systematically achieved over many many years and models fuel consumption
numbers that achieve over a full tank the average official number (mixed town and road),
and over say 40000 miles this number + 0.3l/100km (I am in France and do it the
continental way in litres per 100km). Both petrol and diesel. Its easier with diesel...
I have just bought a new polo and so far (300 miles) I am at 60mpg (still to be "run in").
Previously I owned a Golf estate (2016) with the 1.0tsi 115hp engine and dsg7 gearbox.
During 3 years and 26500 miles I managed an average of 57.5mpg, all driving conditions
distances and weather...
The problem wil downsized turbo petrol engines is you can achieve good and abysmal
numbers. By design my 1.0litre gives the possible power of a 1.5litre, torque of a 1.8litre,
and fuel consumption of a 1.0litre depending on turbo "on" or "off". If you drive with turbo
"on" (ie power and torque) you get the fuel figures of a 1.5 to 1.8litre engine.... On or off
arises from the wastegate valve open or closed depending on throttle usage. Mostly I drive
"off" and get excellent fuel economy, and only when needed turn it "on".