Citroen C5 2.0 Hdi Mpg Info Req

[darko1429]

Hi, 

     New member as of today, just purchased a 2003 Citroen C5 2.0 Hdi manual with 95k. Noticed the fuel is going down rather quickly. Computer says average 42 mpg on A roads but the car has only done 270 miles on half a tank. Is this normal? Also the coolant seems to be pressurising and when left overnight you still get a hiss from the coolant cap when released? Any help would be much appreciated.

Edited March 22, 2017 by darko1429

[paul.h]

Welcome to the forum.

 

You can reset the trip computer by holding in the button on the end of the wiper stalk since if not done it may reflect the driving style of the previous owner. In case the computer is not accurate you should check the mpg by filling the tank, then drive and then fill again and see how much needed to be put in, however, I have found on our cars it is near enough. The fuel tank is 15 gallons but the level gauge is not accurate enough to do mpg calcs and 7½ gallons for 270 miles is 36 mpg.

 

Official mpg from a 2003 sales brochure 2.0 hdi urban / extra urban / combined

- hatchback 90 hp engine manual 36.7 / 60.1 / 49.6

- hatchback 110 hp engine manual 38.2 / 61.4 / 50.4

- estate 90 hp engine manual 36.7 / 58.9 / 47.9

- estate 110 hp engine manual 37.2 / 61.4 / 49.6

Auto gearboxes are less but you have not said your car is an auto.

 

Winter fuel economy is not usually as good as summer but you should check if the brakes are a bit seized since this is a common thing that can reduce fuel economy - just see if the wheel hubs are hot after a run as a quick check before jacking up to spin the wheels. Also the temp gauge should be around the middle showing the engine is warming up properly. If you jack the car up the suspension should be first raised to max height to avoid possible suspension problems. Also do not go under the car without using axle stands since if a height sensor is caught the suspension can quickly drop to a low level. Also check if the air filter has been changed recently.

 

On any car the coolant expansion tank will pressurise as the coolant warms up and expands. Still having a bit of pressure the next day may be normal but I would keep an eye on the level just in case the head gasket is leaking and also look for bubbles in the tank when the engine is running.

 

Have a look at the C5 technical section pinned topic on Common Problems for things to check.

[darko1429]

Thanks, just bought the car and had it fully serviced as well as coolant change. Just worried that 270 miles on half a tank seems low. Had the computer re set when I filled the car up. I was expecting 50 mpg plus, also was hoping for much more than 270 miles on half a tank. What can I expect from a full tank?

[paul.h]

Depending on which engine and if it is a hatchback or estate, from the official figures you should be getting about 48 to 50 mpg, unless you are driving round towns, lots of short trips, driving fast, all of which will reduce it. I have found on the C5 on motorways if you keep to about 65 mph and not above, the fuel economy will be about 5 mpg higher than at 70 mph.

 

From a full tank if you use 12 gallons (54 litres) before refilling, at 50 mpg will give about 600 miles.

[darko1429]

Thanks Paul, I drive to work 20 mins away on A road at approx 50 mph it's a 2.0 Hdi Hatch, manual