Car gets 20mpg less urban than specified, 30mpg less mpg extra urban, ( manufactur mpg ) normal ?

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Insignius

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I bought a 2014 Facelift Vauxhall Insignia 3 weeks ago. 2.0 CDTI Ecoflex.

Fuel

Urban
62.8 mpg ////// I m seeing 40 - 45 mpg

Extra urban
88.3 mpg /////// I'm seeing 58 -60 mpg ( 100 percent solely motorway use )

Combined
76.3 mpg /////// I'm seeing 50 mpg


So basically I am not seeing even above urban mpg alone, most I think I have seen out of it was about 58 mpg which was an all motorway run. 200 miles ( 58 mpg doesn't even exceed the urban mpg figures )


I wasn't expecting for it to achieve the manufacturer specified figures but I am very disappointed for it to be 20mpg less mpg than specified for urban driving and 30 mpg less than specified for extra urban it seems very wrong to me,
All of my previous cars got only about 7 mpg lower than the manufacturer specified mpg, nowhere near as much as 30 mpg less !!

I used the online mpg calculator, enter in how many miles, litres used and price per litre and refill to the brim each time.



( note )
Mine is the engine that is supposed to get higher mpg, some other 2.0 cdti insignias are only listed as getting 51 mpg urban instead of 62.8 urban mpg my model is said to get
 
Last edited:
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Apart from manufacturers figures being done in a wind tunnel or on rollers, those figures were based on a new car 9 years ago. I’m assuming it’s done a few miles since then so a bit worn maybe.
 
Mottie said:
Apart from manufacturers figures being done in a wind tunnel or on rollers, those figures were based on a new car 9 years ago. I’m assuming it’s done a few miles since then so a bit worn maybe.
Click to expand...

The car is 6 years, 9 months old ( 2014 ) covered 82,000 miles

Before this I had a 2007 Vauxhall with 215,000 miles on the clock and it was getting good mpg, only 7 mpg below manufacturer figures, yet this Insignia is showing 20mpg less for urban use and 30mpg less extra urbasn mpg, that's a gross miscalculation by Vauxhall ?
 
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Your actual fuel consumption figures are just fine for a two litre diesel......claimed manufacturers figures are a complete waste of paper.
John :)
 
Mottie said:
Apart from manufacturers figures being done in a wind tunnel or on rollers, those figures were based on a new car 9 years ago. I’m assuming it’s done a few miles since then so a bit worn maybe.
Click to expand...
n
Assuming everything is as it should be with the car, mpg tends to improve as a car gets a few miles under its belt, simply because it loosens up.

As others suggest, you can never achieve the manufacturers ideal conditions figures, but -25% is excessive. I would be checking injectors, watching for smoke from the exhaust, checking for binding brakes etc..
 
Insignius said:
I bought a 2014 Facelift Vauxhall Insignia 3 weeks ago. 2.0 CDTI Ecoflex.

Fuel

Urban
62.8 mpg ////// I m seeing 40 - 45 mpg

Extra urban
88.3 mpg /////// I'm seeing 58 -60 mpg ( 100 percent solely motorway use )

Combined
76.3 mpg /////// I'm seeing 50 mpg


So basically I am not seeing even above urban mpg alone, most I think I have seen out of it was about 58 mpg which was an all motorway run. 200 miles ( 58 mpg doesn't even exceed the urban mpg figures )


I wasn't expecting for it to achieve the manufacturer specified figures but I am very disappointed for it to be 20mpg less mpg than specified for urban driving and 30 mpg less than specified for extra urban it seems very wrong to me,
All of my previous cars got only about 7 mpg lower than the manufacturer specified mpg, nowhere near as much as 30 mpg less !!

I used the online mpg calculator, enter in how many miles, litres used and price per litre and refill to the brim each time.



( note )
Mine is the engine that is supposed to get higher mpg, some other 2.0 cdti insignias are only listed as getting 51 mpg urban instead of 62.8 urban mpg my model is said to get
Click to expand...


Manufacturer figures are inflated, some more so than others,

If it seems to be running as it should then nothing to worry about.

What speeds are you doing on the extra urban run? The manufacturer figures are done at 55mph.

The book figures are obtained in test conditions in doors usually on a rolling road, this creates headline hitting mpg figures due to there being less resistance.

In real world you have much more resistance with all sorts of variables, wind, rain, to hot, tyre pressures weight, etc all have a part to play.

The reason they use the method they do for mpg figures isnsonthey are repeatable (in a lab) and compare to different manufacturers all knowing that the test conditions are the same
 
Re your extra urban figures, a member on a boat forum claimed +80mpg on a 200 miles mostly motorway trip recently in the same car, admittitly the car is newer with less miles though and I don`t know the average speed.
 
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