Official vs Real World Fuel Economy

Jonnycoupe · 10 Mar 2011 at 11:40

eatcustard said:
Over inflated tyre pressures is a myth, your car will run worse.

It will reduce rolling resistance.

Ive seen coast down loss results that prove this.

Finglonga · 10 Mar 2011 at 12:06

BMW E92 335i Auto been on 27.9 for s few months now, combined is 33.6 for the 2011 model but sure it was around 31 for the 2009 but can't find the figures.

[TW]Fox · 10 Mar 2011 at 12:07

Finglonga said:
BMW E92 335i Auto been on 27.9 for s few months now, combined is 33.6 for the 2011 model but sure it was around 31 for the 2009 but can't find the figures.

30.7mpg.

What sort of driving do you do?

EddScott · 10 Mar 2011 at 12:13

DiamondMark said:
12 to the gallon, you can have mine now

Only slight worserer than mine.

Completely town driving for the last tank the average says 13.4mpg. Jeep official urban MPG is 16. Not far off and not entirely sure whether we are talking UK or US gallons. I think its all US gallons.

Got 175 miles from the last £80 fill up all urban.

gt_junkie · 10 Mar 2011 at 12:16

2003 Focus 1.6 petrol.

Actual is between 40-43mpg (over the past five tank fills)

Only official combined figure I can find is 40.9mpg

gt

mattyprice4004 · 10 Mar 2011 at 13:42

Damn, just filled up after a trip over the last couple of days... 19mpg. Claimed 30mpg from the manufacturer. Oops!

Kenai · 10 Mar 2011 at 13:48

Lucero said:
In order for this test to be anywhere near conclusive, we must all have the ability to drive as they do on the test, with overinflated tyre pressures. If you expect me to drive normally, the results will always be as everyone expects.....wrong!

The tests are done on a rolling road anyway, with simulated resistances, so you're never going to manage to repeat those conditions on the road, it's too artificial.

LizardKing · 10 Mar 2011 at 14:22

Official stats - Golf 2.0 tdi 140

EC Urban (mpg) 46.3
EC Extra Urban (mpg) 68.9
EC Combined (mpg) 58.9

I tend to get ~45mpg. Thats 90% spent on duel carriageway as well.

The GTO's official figure is 18mpg for combined, I dont work out what i get but I'm sure its a lot less than that!

Finglonga · 10 Mar 2011 at 16:55

[TW]Fox;18640503 said:
30.7mpg.

What sort of driving do you do?

Not been on motorways since last reset, mainly A&B road hooning and commuting is not in the rush hour and dual carriageway so no sitting in traffic for long.

[TW]Fox · 10 Mar 2011 at 16:57

Finglonga said:
Not been on motorways since last reset, mainly A&B road hooning and commuting is not in the rush hour and dual carriageway so no sitting in traffic for long.

Very impressive

lukechad · 11 Mar 2011 at 22:50

I wasnt convinced that after some 20,000 miles without resetting the average MPG on my car that I was getting a more "new me" figure when it comes to my driving style. So, I reset it some 500 miles ago now...

Previous average - 32.4MPG

New average - 29.4MPG

Manufacturers claim is about 35mpg on a combined cycle.

BeatMaster · 11 Mar 2011 at 23:03

2004 Ford Focus 1.6 Edge
Combined 40.9 MPG

[TW]Fox · 11 Mar 2011 at 23:06

What sort of driving is that? I see figures like 38mpg from a 1.6 petrol and wonder whether these eco-cars are worth the bother

If thats all town then fair enough I guess..

Jonnycoupe · 11 Mar 2011 at 23:11

2004 1.6 Focus isnt really an eco special though. I wish my Focus 1.8 got near that! Especially if its a tank average as oppose to an M5 jaunt

Eco side is the cost of changing tyres. Ive seen you pistonheads blog, and I converselt have to wonder if these older premium saloons are worth the bother.

Pretty poor aerodynamics on that shape though and the older Zeta engine on the larger = fail.

[TW]Fox · 11 Mar 2011 at 23:14

Jonnycoupe said:
Ive seen you pistonheads blog, and I converselt have to wonder if these older premium saloons are worth the bother.

Probably not to be honest. You know they are a waste of time when you run the numbers on replacing it with with something worth 7 times as much and it works out to cost barely anything extra to run...

Gaijin · 11 Mar 2011 at 23:18

BeatMaster said:
2004 Ford Focus 1.6 Edge
Combined 40.9 MPG

What app is that?

lordrobs · 12 Mar 2011 at 00:52

Cripple said:
Presuming you have the non-turbo Grande Punto?

Yeah non turbo Eleganza.

Economy even on longer trips is disappointing if I'm honest.

viper_2003 · 12 Mar 2011 at 07:24

2005 Volvo S60 D5

Claimed is 43.5 mpg combined, in the last week on a new commute to work (30 miles each way, across country) I have been getting 48 mpg (display shows 54.3 mpg but over reads by exactly 6 mpg).

BeatMaster · 12 Mar 2011 at 09:06

[TW]Fox;18652751 said:
What sort of driving is that? I see figures like 38mpg from a 1.6 petrol and wonder whether these eco-cars are worth the bother If thats all town then fair enough I guess..

It's a mixture of all sorts of driving, however 60% is A and B roads with a good 20% town driving. The high of 45 was on a long run down to Alton Towers from Newcastle. The lows were during the winter months.

I'm hopefully going to be getting a facelift Focus ST in the coming months. 15MPG less but 225bhp

Gaijin said:
What app is that?

Road Trip LE

Fusion · 12 Mar 2011 at 09:22

Ford Fiesta 1.25 Finesse MK6

Official:

Fuel consumption (urban) 32.8 mpg
Fuel consumption (extra urban) 57.6 mpg
Fuel consumption (combined) 45.6 mpg

Real world:

Over a tank I got ~37 mpg, and this was mostly shorter trips/urban driving. A long motorway trip will yield about 48 mpg at 65/70 mph.

Not really that economical when compared with some figures here. A 1.6 Focus seems to return similar figures. My driving style could be smoother, on motorways and dualled A-roads I tend to overtake a fair bit. If I stuck more firmly to a constant speed then I could get 50 mpg most likely.

A recent trip from near Sutton-in-Ashfield, Notts to Duxford (near Cambridge) and back only gave me 45-46 mpg but the A1 is so cramped, congested and badly designed in the non-motorway parts that it's harder to maintain your speed than on a higher capacity, free-flowing motorway.