MPG... What's the problem?

Td4, since 12.12.12, 3000km done so far,
fuel consumption ok:
8,7l/100km On motorways with cruising Speed of 100km/h in average;
driving 140-160km/h it takes 12l/100km

SD4 Auto, 3500 miles (in 6 weeks!!!!!)

36mpg overall average, rising to 41 mpg on motorway at 75mph.

Happy enough with that as its about the same as our AWD Kuga which is a manual.

Cheers

Mark H

(04-01-2013 03:42pm)Zesty314 Wrote:  SD4 Auto, 3500 miles (in 6 weeks!!!!!)

36mpg overall average, rising to 41 mpg on motorway at 75mph.

Happy enough with that as its about the same as our AWD Kuga which is a manual.

Cheers

Mark H

If I set the cruise control at 75 I don't get anywhere near 36, I'm lucky to get over 32.

(05-01-2013 05:12pm)wavey.dave Wrote:  If I set the cruise control at 75 I don't get anywhere near 36, I'm lucky to get over 32.

Yep I get about 33-34 at 75... I know there's quite a difference in wind/conditions etc etc but still seems odd others can get over 40 !?!?

Typically 37-39mpg when on cruise at 75mph. Doing a trip south today on M6 so will reset it and see what I get

Managed to see 43.5 mpg on the dash readout over Christmas, but then I had been driving at 70 mph for a short while then a long stretch at 60mph and a slow 40mph to centre of London on the M4 in relatively quiet traffic. If I could have stopped I'd have taken a momento picture of the dash! Doubt I'll see that figure again though....back in real world driving I'm getting 27mpg in heavy stop start traffic and around 31 mpg in town where traffic is flowing....reaching heady heights aof 33/34 on motorways usually. Not what I had expected from this vehicle. Shame really, it takes the edge of what is a superb car.

it all depends on the pressure you put on the gas-pedal...
Constructors do not now how you drive the car, i only filled up mine twice so i really can't
tell for the moment but my jeep grand cherokee drinks 14l/100km when my wife drives it
and he drinks 11l/100km when i drive it.
But my wife drives like schumacher and i drive lets say normally...

---

our fiat twin air 900cc should consume 4,9l/100km on paper but with my wifes foot it takes 8,5l/100km easily

Wavey.Dave,

It is well known that using cruise control is actually incredibly fuel inefficient and will significantly increase consumption over if you drive yourself. This is to do with the logic that is set into the transmission when cruise control is active. It keeps gears in place even when it isn't the most fuel efficient gear to avoid excessive up and down shifting while tying to maintain a speed. Try the same drive without cruise control and i guarantee you will notice better mileage.

(05-01-2013 05:12pm)wavey.dave Wrote:  If I set the cruise control at 75 I don't get anywhere near 36, I'm lucky to get over 32.

I drive quite regularly from Suffolk to Geneva via the Tunnel in an SD4 automatic. Once in France I cruise at between 75 and 80 mph for around three hours at a time; this type of driving returns 33 to 34 mpg. I occasionally use cruise control and find it makes no noticeable difference to fuel consumption. I can return close to 40 mpg but only by not exceeding 55-60 mph unless going down a hill. I do wonder over what distance some of these high figures are obtained; 500 miles of traffic free motorway is a good distance over which to measure consumption. The UK motorway leg which is around 120 miles and on which I keep close to 70 mph usually returns 36/37 mpg.

When very new coming south on M6 in 60mph traffic I got the trip up to 47mpg!!! having filled up literally on the slip road.. but the minute I hit an upward slope toward the M6 Toll it dropped to 42, the minute I sped up to 70mph on the toll it dropped to 38... since I actually had to press the throttle pedal!