wrote:
On 18 May, 08:38, "Depresion" 127.0.0.1 wrote:
"DervMan" wrote in message

...





"Nick Finnigan" wrote in message
...
DervMan wrote:
Brand Type Fills MPG MPH
ASDA Supermarket, 3 fills, 50.2 mpg, 39.0 mph
BP Ordinary, 8 fills, 50.2 mpg, 38.9 mph
BP Premium, 6 fills, 51.0 mg, 38.1 mph
Shell Ordinary, 44 fills, 49.8 mpg, 37.9 mph (my control fuel, 'cos I use
Shell the most often)
Shell Premium, 8 fills, 49.7 mpg, 36.5 mph
Tesco Supermarket, 3 fills, 48.8 mpg, 37.3 mph
Total Ordinary, 3 fills, 47.4 mpg, 36.2 mph
The data above might suggest that Shell V-Power Diesel is slow and
thirsty. It just means that over these tanks the Saab spent longer in
the city.
I would look at you Shell Ordinary fills and see if they do support the
apparent trend that your mpg is proportional to your mph. And then you can
conclude that Tesco has too much bio, and the premiums are better.
Maybe: but three runs isn't enough to be statistically significant. 40
runs, maybe...
Looking at your figures, try averaging 100mph for a while, will save you a
fortune.

Slower average speed suggests more stop-start driving.

For the record, I've had a notable improvement in the MPG from my
Passat since the weather has warmed up, and this seems to have been
the case with most of the diesels I've had over the past few years.

I believe they have to blend diesel to a different formula to ensure
it doesn't solidify in colder weather so this might partly explain why
I've generally seen less MPG in winter time than in summer... although
the need for things like the lights / rear heated screen / heater fan
etc, to be on more in the winter months might be a factor as well.

--
JackH
Well, that's exactly what I've found before now.