Sasol 50ppm diesel vs Engen 50ppm
An update, since I now have more data from my logbook over a period of almost 18 months and 30 000km:
Sasol: 8.36 l/100km. Std dev 0.82 l/100km
Engen: 7.90 l/100km. Std dev 0.25 l/100km
5.5% drop in consumption with Engen.
I changed from Sasol to Engen in April 2014, after I logged a formal complaint regarding an inaccurate pump. Still awaiting feedback on that one. Very average customer service. As I mentioned previously, this may also be indicating that Engen's pumps are more accurate (hence the lower standard deviation values) as opposed to fuel quality and/or variability. Graphical plots of the data suggest this rather strongly. I'm just reporting what I'm seeing.
The above data is based on:
Sasol: 12934 km, 18 fill-ups Aug 2013 to Apr 2014, 1117.11 litres at a cost of R15 172.67
Engen: 16589 km, 21 fill-ups May 2014 to Jan 2015, 1308.667 litres, at a cost of R17 104.64
Actual consumption calculated when filling up, not based on OBC values.
Out of interest, the onboard computer values have dropped from an average of 7.9 to 7.6 l/100km. The computer consumption under-reads by around 3% on my vehicle.
Virtually identical daily vehicle usage throughout this period, mostly highway, with some city traffic. 2009 E83 2.0d MSport manual.
The vast majority of the fill-ups were at one Sasol garage and one Engen garage in PE. During this period there were only 4 sporadic fill-ups at other garages (2 x BP, 1 x Total and 1 x Caltex).