Fuel Economy, what am I doing wrong?
Discussion
Recently brought a incredibly "sensible" car to enable me to do a 2 hour daily commute in comfort and great MPG.
It's a 2009 citroen c5 2.2 Diesel
I mainly do motorway cruising at 75-80 and a few little back roads and do about 120 miles a day.
I was expecting to be getting about 50mpg average ideally! However, no matter how I drive it I cannot get the avegare mpg above 34.2!
Even cruising along the motorway at 65 mph in 6th gear with cruise control I'm only getting 42 mpg!
What is going on?
It's a 2009 citroen c5 2.2 Diesel
I mainly do motorway cruising at 75-80 and a few little back roads and do about 120 miles a day.
I was expecting to be getting about 50mpg average ideally! However, no matter how I drive it I cannot get the avegare mpg above 34.2!
Even cruising along the motorway at 65 mph in 6th gear with cruise control I'm only getting 42 mpg!
What is going on?
Edited by sidekickdmr on Monday 5th March 15:20
I think your first mistake was buying a car that achieved 43mpg on the combined cycle test and excepting it to get 50mpg in the real world.
Between 75-80 I'd expect mid to high 30's so its not doing much worse than expected tbh. If you wanted to save lots of money you probably should have bought a fuel efficient diesel.
Between 75-80 I'd expect mid to high 30's so its not doing much worse than expected tbh. If you wanted to save lots of money you probably should have bought a fuel efficient diesel.
.its a fairly heavy car, but that wont matter too much when cruising, just accelerating. It looks fairly sleek so I wouldn't of expected it to have lots of aero drag to make the engine work harder.
Have you checked tyre pressures? What fuel station do you use?
You should check on spritmonitor.de to see what others get from their cars. They post in l/100km so you need to find an imperial converter to get the right MPG (careful of ones converting to US MPG).
Have you checked tyre pressures? What fuel station do you use?
You should check on spritmonitor.de to see what others get from their cars. They post in l/100km so you need to find an imperial converter to get the right MPG (careful of ones converting to US MPG).
Otispunkmeyer said:
They post in l/100km so you need to find an imperial converter to get the right MPG (careful of ones converting to US MPG).
Just use google, eghttp://www.google.co.uk/search?q=24l%2F100+miles+i...
or
http://www.google.co.uk/search?q=24l%2F100+km+in+m...
My use of heated seats/rear screen, lights, winter tyres over the winter has dropped my typical mpg by almost 10.
Hopefully you'll get better as it warms up. In the meantime might be worth checking the tyre pressures, treating it to a service, a tank of decent fuel and a good Italian tune up.
Hopefully you'll get better as it warms up. In the meantime might be worth checking the tyre pressures, treating it to a service, a tank of decent fuel and a good Italian tune up.
If you really want to get those high mpgs...
1. Don't use cruise - it's too heavy footed. Use your foot lightly.
2. Accelerate at the lowest rate that's acceptable. Under 2k is my glacially slow acceleration rpm for a petrol Primera (not always sensible to do this though).
3. Drive at 55-60mph.
4. If you have instant mpg readout, use this to keep it in target range.
5. Sit behind a big flat backed lorry. Not tailgating, but bang on the 2 second rule. Use their turbulence to reduce your wind resistance.
Doing the above I've got 45mpg out of a petrol Primera estate.
1. Don't use cruise - it's too heavy footed. Use your foot lightly.
2. Accelerate at the lowest rate that's acceptable. Under 2k is my glacially slow acceleration rpm for a petrol Primera (not always sensible to do this though).
3. Drive at 55-60mph.
4. If you have instant mpg readout, use this to keep it in target range.
5. Sit behind a big flat backed lorry. Not tailgating, but bang on the 2 second rule. Use their turbulence to reduce your wind resistance.
Doing the above I've got 45mpg out of a petrol Primera estate.
Slow down. Its easy. 75-80 should be more like 65.
Bit of a change to make, but it's perfectly possible. It's so easy tooltip that speed, relaxing, laughing at those in the brake check lane. And it really does make barely bugger all difference to your journey time once averaged out a bit.
Bit of a change to make, but it's perfectly possible. It's so easy tooltip that speed, relaxing, laughing at those in the brake check lane. And it really does make barely bugger all difference to your journey time once averaged out a bit.
Don't forget 2.2 litres is still 2.2 litres even in a Diesel.
43mpg on a motorway sounds about right to me. As others have said cruise control actually uses more fuel. Think about it the car goes up a hill loses speed so the ECU floors it to get the speed back up. Whereas a driver can anticipate the hill and accelerate slightly to compensate for the upcoming hill. You might not realise you do it but trust me you do.
If you really want to try and improve it, I'd try putting premium Diesel from Shell for a month or so. It might give it a good clear out. Might not work but worth a try.
Nice car by the way, like the C5 a lot and I'd choose it over a Mondeo or 3 series any day.
43mpg on a motorway sounds about right to me. As others have said cruise control actually uses more fuel. Think about it the car goes up a hill loses speed so the ECU floors it to get the speed back up. Whereas a driver can anticipate the hill and accelerate slightly to compensate for the upcoming hill. You might not realise you do it but trust me you do.
If you really want to try and improve it, I'd try putting premium Diesel from Shell for a month or so. It might give it a good clear out. Might not work but worth a try.
Nice car by the way, like the C5 a lot and I'd choose it over a Mondeo or 3 series any day.
I wanted to see what the Saab would do if driven with an eye on fuel economy, so I reset the trip computer on Saturday (it was showing 26mpg after my wife had been commuting in it). I then drove from my house near Swindon to Goring in South Oxfordshire and back and then the next day to Calne and back, in each case with the car parked for a few hours at the destination. Total, about 60 miles of motorway/dual carriageway done at 70 in cruise and about 50 miles of A and B roads. At the end of this, it was claiming 34mpg. That's in a 2.3 litre 250bhp petrol estate that weighs over 1700kg.
The MG (2.0 cdti diesel) in winter and doing short urban journeys, averages about 38mpg and goes up to mid 40's on a run. The Saab 9-3 1.9 TiD I was driving last winter averaged around 43-45mpg with a mix of driving (but never too gently).
I'd say that with the type of driving you're doing, you're at least 7 or so mpg down on what you should expect.
I'd certainly check all filters have been recently replaced and for the sake of 30 mins, jack each corner and check for free movement.
I'd say that with the type of driving you're doing, you're at least 7 or so mpg down on what you should expect.
I'd certainly check all filters have been recently replaced and for the sake of 30 mins, jack each corner and check for free movement.
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