As any one got a view on service interim oil changes? my new C4 1.6 HDI as now done 6K and I am considering an interim oil and filter change, obviously using a proper Citroen (Mahle I think) filter and the specified oil which is Total Quartz ineo ECS. Below is the wording of what supposedly was a technical bulletin issued by Citroen regarding the correct procedure for changing the oil on the 1.6 Hdi unit. It specifically states that suction methods should not be used. (I can't verify that this was a genuine, Citroen-issued Technical Bulletin.) OIL CHANGE PROCEDURE ON ALL DV6 ENGINES 怐TOP DEAL怑āš”ļø Order Oil filter for CITROŠN C4 II Hatchback 1.6 BlueHDi 100 99 hp easily at AUTODOC Fast delivery and low prices Discover now for yourself SHOP PARTNERS CLUB Info: CitroĆ«n C4 mk2 1.6 BlueHDi 100 Total QUARTZ 7000 10W40 is the recommended oil. Total INEO ECS 5W30 is also fine, slightly more pricey but perfectly OK for the HDi. You're right indeed that the oil is important on the 1.6HDi. If you use a big standard oil, you're likely to get soot from combustion forming around the EGR valve which eventually clogs it up. Model Motor Capacity / Capacity with liter filter Oil change interval; Grand C4 Picasso 1.6 VTi (2008 - 2013) E: 4.2: 30 km / 000 months: Grand C4 Picasso 1.6 THP (2008 - 2012) uZ70f.