[AusKiwi]

I just found this forum, and as I was independently doing some economy driving of my own, I thought I'd join up and share what I'm doing. I bought a 2003 Citroen C5 2.0HDi turbodiesel last year. This is already an amazingly economical car, due to the diesel engine and the reknowned Citroen aerodynamic shape. I get about 6.9 litres/100km running to and from work every day. What I am currently testing, to see if the claims made about these products are true, is the range of oil and fuel additives from Pro-Ma Performance. I added their MBL8 oil additive to the engine on my last fill, so will find out next week if the claimed 5% fuel savings eventuates. After that I will add some DT5 Plus Diesel Treatment to the fuel tank, and run a tankful through the car to see if the 12% savings other diesel users are experiencing, is something I can get too. Will update this post when I have results.

Update 28/8/14 The fuel consumption has dropped from 6.89 to 6.21 l/100km now that both the MBL8 oil additive, and the DT5 Plus Diesel Treatment are being used. This is a combined improvement of about 9.9%. I am very happy with this result, and am hoping that as the Pro-Ma products continue to work their magic on the internal parts of the engine and fuel system, fuel economy may even improve further.

Update 12/8/14 The fuel consumption dropped from 6.89 to 6.81 l/100km after the MBL8 oil additive was used. This is only a 1.16% improvement, however I didn't plan this test very well, as my wife and I holidayed in Surfers Paradise for a week during the test. This involved a lot of stop-start city driving whereas normally my daily commute is mostly on the freeway. So the data is probably a little skewed.

Anyway, I hope to complete the next phase of the test (the DT5 Plus fuel additive) in a few weeks. I'll be happy to see a combined improvement of 10%. So far my trip computer says the car is averaging 5.7 l/100km however the trip computer has always been more optimistic than my own calculation based on litres filled at first click of the pump divided by km since the last fill. Still, given that the trip computer showed 6.5l/100km on the last tank, 5.7 is a 12.4% improvement which is consistent with what others have reported with DT5 Plus. I'll just have to see if those figures stay the same over a tankful of fuel.