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chunderground · Apr 25th, 2010, 18:47

I get 23.5 average journey 5 - 10 miles not really heavy footed. Was only getting 21.8 in winter with heated seats on and colder starting. I have heard they improve gradually until they reach 10,000 miles
New 185 bhp d5 with particulate filter are much heavier on fuel than pre 2007 models despite the manufacturers claims
The particulate filter on all modern diesel engines needs a 20 min motorway blast every 300 - 400 miles to burn off the soot otherwise the engine runs with a richer mixture to increase the exhaust temperature to clear the soot filter. Read blogs from all other makes of car you will see the same story. The AA made a report on this subject because some makes of diesel engine will go into limp mode if the filter becomes clogged. Not such good news for school run users but that eu regs for you. Saves couple of hundred on road tax but we lose on fuel consumption. I have tried really light driving and it makes no difference , but I love the car and so am prepared to put up with higher than expected running cost (bit like my woman I suppose). Any way keep me posted if things improve but I think your consumption is par for the course.
So in summary the lower co2 emissions do not come from increased efficiency but from a filter which increases load on the engines so the engine has an increased power output to overcome this and inevitably uses more fuel. Sorry its bad news !!!

Apr 25th, 2010, 18:47	#11
chunderground xc90 exec black+privacy Last Online: Jul 12th, 2012 17:45 Join Date: Feb 2010 Location: london	xc90 2009 d5 exec with 4500 miles I get 23.5 average journey 5 - 10 miles not really heavy footed. Was only getting 21.8 in winter with heated seats on and colder starting. I have heard they improve gradually until they reach 10,000 miles New 185 bhp d5 with particulate filter are much heavier on fuel than pre 2007 models despite the manufacturers claims The particulate filter on all modern diesel engines needs a 20 min motorway blast every 300 - 400 miles to burn off the soot otherwise the engine runs with a richer mixture to increase the exhaust temperature to clear the soot filter. Read blogs from all other makes of car you will see the same story. The AA made a report on this subject because some makes of diesel engine will go into limp mode if the filter becomes clogged. Not such good news for school run users but that eu regs for you. Saves couple of hundred on road tax but we lose on fuel consumption. I have tried really light driving and it makes no difference , but I love the car and so am prepared to put up with higher than expected running cost (bit like my woman I suppose). Any way keep me posted if things improve but I think your consumption is par for the course. So in summary the lower co2 emissions do not come from increased efficiency but from a filter which increases load on the engines so the engine has an increased power output to overcome this and inevitably uses more fuel. Sorry its bad news !!! Last edited by chunderground; Apr 25th, 2010 at 18:53.