Hi there
I live in South Africa and I own a 2006 Q7 with the 3,0 TDi motor
I bought the car when it had 94 000 km (abt 58 000 miles) on the clock and it has now done 140 000 km (abt 86 400 miles). I was never impressed with the fuel consumption, but I reckon I could always drive in a more civilised fashion...
According to the onboard computer, my average fuel consumption is is around 11,1 l/100km (abt 25,4mpg). I feel that the car weighs around 2,5 tonnes, is AWD and it stands fairly high off the ground, so it is more or less acceptable to me.
But I do know someone with an A6 with the same drivetrain and he gets in the region of 40-45 mpg.
On the open-road I manage to stick to the discipline of setting the speed control at a true 80mph, which keeps me out of harm's way with the speed traps - even if only just.
That just as an aside. I am actually looking for your sage advice. The car recently started smoking. I am used to a TDi smoking on heavy accelleration, but my car smokes at idle too.
The workshops I've been to tell me (after a check with the Bosch magical diagnostic machine) have the injectors have to be replaced and the cost ranges from ZAR5500 to ZAR7600 +14% vat. At almost ZAR to the GBP, you're looking at about GBP366 to 507. Each.
That is simply not an option for me at the moment. I understand that this problem is making the engine run richer than it should, but there will be no damage to the engine.
I have also been told that the injectors cannot be cleaned, "because it runs a secondary injection system". What-the-hell-ever that means in human.
As far as fuel is concerned, in South Africa we have 500ppm and 50ppm diesel, the latter being cleaner, having only 50 parts per million of heaven-knows-what - sulphur, lead, anthrax... But there is absolutely no difference between brands, because the fuels all come from the same refinery here.
And I only use the 50ppm. I do believe that diesel is even cleaner in the UK and Europe?
Anyways... I am hoping to get advice about some magic potion that you can add to a tank of fuel that will at least clean the injectors a little bit.
Please tell me I do not hope in vain...