Hi ......... I have had my C4 Grand Picasso 1.6 Hdi manual 2009 for about 2 years.
It hadn't been serviced in that time unfortunately but it was returning approximately 50 mpg, also .
for each of the 12 notches on the fuel gauge it was getting around 50 miles.
Recently I booked the vehicle into a Halfords Autocentre locally for a major service and asked for them to keep my old pollen and air filters.
New Mobil 1 ESP was also used to replace the old black oil.
Now I am finding that my fuel economy has been severely affected returning 103 miles each 3 notches instead of around 150 miles.
HOW CAN THIS HAPPEN? Any ideas what might have caused this? I thought with clean quality oil and new filters it would slightly do better on fuel, not a lot less! Hoping anybody can advise me on this and if I emailed a complaint to Halfords H O what could I say?
Thanks in anticipation.