55 Ford Focus 1.8 tdci - 55 Focus tdci Bad Fuel Economy

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Thu 20 Jan 2011 20:23
55 Ford Focus 1.8 tdci - 55 Focus tdci Bad Fuel Economy - bobby1ster

I used to get around 550 miles to a full tank although I have noticed over the last month or two it seems to be drinking fuel. I now seem to be getting around 400 to 450 miles out of a full tank even though around 90% of my driving is on the motorway I have dropped my speed down to 55 - 60 mph over the last few weeks to see if that helps but to no avail.

On my old Vectra (1996) diesel I used to put redex in now and again and this certianly helped is this a wise thing to do with the tdci? The manual certainly seems to suggest you avoid it.

Is there anything else that could be wrong? The clutch isn't slipping so I don't think that is a problem and the tyres are at the correct pressure. I have read that a sudden loss of fuel economy can be down to a failing turbo unit?

Any ideas anyone?

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Thu 20 Jan 2011 22:02
55 Ford Focus 1.8 tdci - 55 Focus tdci Bad Fuel Economy - Peter.N.

Not knowing how big your tank is I can't work out the mpg but at 60 mph you ought to be getting at least 50 mpg if driven with a little restraint. Is it smoking at all, is there any loss of performance, is the engine running at normal temperature?

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Thu 20 Jan 2011 23:07
55 Ford Focus 1.8 tdci - 55 Focus tdci Bad Fuel Economy - mikej

The petrol tank for the mk1 was 55 litres, so the mk2 is probably the same ?

I used to get up to 400 miles from a tank in my 1.8 petrol which is around 32-33mpg, so it sounds like you've got a problem somewhere.

Edited by mikej on 20/01/2011 at 23:08

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Fri 21 Jan 2011 10:11
55 Ford Focus 1.8 tdci - 55 Focus tdci Bad Fuel Economy - bobby1ster
I think the tank is 52.7 mikej but your right something is up not sure if its safe to put some redex in to clean the system with these modern diesels.
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Fri 21 Jan 2011 10:09
55 Ford Focus 1.8 tdci - 55 Focus tdci Bad Fuel Economy - bobby1ster
Thanks Peter I'll have to dig the manual out for the tank size although I believe most models are 52.7 liters - 11.59 gallons so it should be around 579 miles at 50mpg although of course under most driving conditions you would not achieve this. I have certainly in the past made 550 although i was getting to empty which you really should not do.

There isn't any loss of performance and the engine is running at the correct temperature (although I do have the erratic temp gauge which seems to a software problem that has plagued many people) and its not smoking.
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Fri 21 Jan 2011 12:13
55 Ford Focus 1.8 tdci - 55 Focus tdci Bad Fuel Economy - Peter.N.

The only way you can accuratly check is by filling the tank to the brim, noting the mileage and then again the next time you fill up, not perfect but as near as you will get.

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Fri 21 Jan 2011 13:16
55 Ford Focus 1.8 tdci - 55 Focus tdci Bad Fuel Economy - madf

The explanation is called Winter.

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Fri 4 Feb 2011 21:00
55 Ford Focus 1.8 tdci - 55 Focus tdci Bad Fuel Economy - dh1983
I recently had a major service and instead of 550 miles pre tank its down to 420 once I filled up.
I assumed this was because they've changed all the filters! Although I thought I would get more miles out my car for the filters being clean and engine working more efficiently???

Saying that ive driven down south today 300mls and avg 58 mpg according to the car. Which isnt bad for my 2.0 tdci. Fuel gauge is halfway so I will see how it plays out.
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