DervMan wrote:
"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...

If those 40 runs all come within 1% of 0.77 gallons/hour, and the BP
ordinary ones do too, but the premiums always come out within 1% of 0.74
gph then the 3 runs can be significant. (Tesco is OK on a closer look).