CRD high fuel consumpition, 11L/100km 21mpg

[TePe]

I recently bought a 2006 300C CRD Touring. Based on what I've read on the forum and the official figures I think my CRD likes to drink a lot more fuel than it should.

11L/100km (21mpg) is a lot worse than I expected, especially as I drive about 30% on the highway, 30% motorway, and only 40% in town.

What could cause such a rise in fuel consumption? Injectors, thermostat, ...? There are no trouble codes, the engine seems as powerful as it should, and the brakes don't seem to drag. Everything seems just fine, except for the high fuel consumption. Any suggestions?

[paul@thecustom300cshop]

Hi has it been Serviced??





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[TePe]

Originally Posted by paul@thecustom300cshop

Hi has it been Serviced??

Hi Paul,

Yes, I had the engine oil & filter, air filter, coolant fluid and transmission fluid changed and the A/C serviced when I bought it. Is there anything else that should be serviced? The car has done 149.000km / 92.500 miles.

[paul@thecustom300cshop]

2.41 gallon over 62 miles ??? = 25.72 not that bad seen worse

[Boro al]

Originally Posted by TePe

I recently bought a 2006 300C CRD Touring. Based on what I've read on the forum and the official figures I think my CRD likes to drink a lot more fuel than it should.

11L/100km (21mpg) is a lot worse than I expected, especially as I drive about 30% on the highway, 30% motorway, and only 40% in town.

What could cause such a rise in fuel consumption? Injectors, thermostat, ...? There are no trouble codes, the engine seems as powerful as it should, and the brakes don't seem to drag. Everything seems just fine, except for the high fuel consumption. Any suggestions?

You have presumably taken the 21mpg from the evic and yours will be registering in US gallons that are smaller, you have to add 20% to the reading and that will equal 25.2 mpg.

[Simon@thecustom300cshop]

It does sound like your evic has old software in it. 11 litres is almost 26 UK mpg as already mentioned. Not great but have seen worse on mine. Do you know if the car has been remapped or has got a tuning box fitted?

Worth checking for fuel leaks around the fuel filter pipes and the joints up above the alternator, also make sure your tyre pressures are not a bit low.

[TePe]

Thanks for all your comments!

Actually the evic shows 10.8 L/100km, but I've calculated the actual fuel consumption to be a bit over 11 L/100km. I took the mpg from Google converter. So it's 11 L/km, 21 US mpg, 26 UK mpg.

Anyway, talking to other Finnish owners the car should do at least 35 UK mpg as I'm driving mainly on highways. I'll check it for fuel leaks, but I think there's more to it than that. Could it be something MAF sensor or temperature sensor related? The ECU thinks it's running cold or lean and injects more fuel? The weird thing is that there are no fault codes..

There's no tuning box, and I'm pretty sure it hasn't been mapped. Yet.

[Simon@thecustom300cshop]

It could be, if it thinks the engine is cold the idle will be a little higher all the time. I wonder if its been remapped, no way of telling unless you can get a tuner to download and look at your current map.

[pesty]

Seems low to me. I do mainly motorway miles and if i behave I get 35mpg.

Goes down to 30/31 if I am impatient to get home.

[jeyaar789]

35 miles per UK gallon averagely , I've had it up to 53 mpg on a long motoway slog at a modest 60mph.