Fuel consumption: advertised vs real world

Given that people are buying cars based on their advertised L/100km (MPG) I am curious how posters here fare.

My anecdotal evidence has larger engines stay closer to their advertised fuel consumption, wondering if that's true.

I've a 07 2.2CRDI Santa Fe advertised at a combined 7.6 L/100 km
I'm pulling 7.5L/100km so doing better than expected.

My old 2001 1.6 base Passat was thirstier based, I'm assuming, on being such a small power plant in a large body

NIMAN

Everyone knows that the manufacturers MPG figures are pie in the sky stuff. How they are allowed to get away with publishing them I'll never understand.

Most of these are achieved on a test track at a steady mph, one which produces the best efficiency for the engine. Plus all the unnecessary weight is taken out of the car, seats, stereos etc. Its basically stripped bare and they leave only a drivers seat and the shell. Plus they tape over all the areas of the car which can catch wind and create drag.

So as you can see, these are very 'real world' tests, absolutely like how we drive our cars!

I recently changed to a 1.6TDi Bluemotion Golf....God knows what they would say I'd get on that, but according to the cars computer, I'm getting just over 55mpg. My previous Ford Econetic was showing 61mpg, when I think Ford said it gets 72mpg.

They are mostly nonsense.

Steve

VW 2011 2.0 TDI/170 getting about 6.5 on trip 2 which has about 6500km on it..

Steve

NIMAN wrote: »

I'm getting just over 55mpg. My previous Ford Econetic was showing 61mpg, when I think Ford said it gets 72mpg.

What's that in real units?

pm.

2016 3.0 tdi A4 quattro 8.1 Ltr per 100km 😦

pred racer

If you look at the car ads closely, most of them do say that the L/100Km figures are not achievable in the real world and should only be used for comparison.

I dunno what the advertised figures for my car are (14 opel insignia CDTI 163) are but it did run at 6.1-6.2L/100KM. since the remap it 'says' its now running at 5.6L not sure I see any real difference tank to tank.

Edit: I just looked it up and the advertised figure is 4.5L/100Km which is impossible for that car.

bmwguy

NIMAN wrote: »

Everyone knows that the manufacturers MPG figures are pie in the sky stuff. How they are allowed to get away with publishing them I'll never understand.

Most of these are achieved on a test track at a steady mph, one which produces the best efficiency for the engine. Plus all the unnecessary weight is taken out of the car, seats, stereos etc. Its basically stripped bare and they leave only a drivers seat and the shell. Plus they tape over all the areas of the car which can catch wind and create drag.

So as you can see, these are very 'real world' tests, absolutely like how we drive our cars!

I recently changed to a 1.6TDi Bluemotion Golf....God knows what they would say I'd get on that, but according to the cars computer, I'm getting just over 55mpg. My previous Ford Econetic was showing 61mpg, when I think Ford said it gets 72mpg.

They are mostly nonsense.

As far as I know the test is done at a constant 39 mph on a rolling road.

CiniO

My car manufacurer spec is:

5.1 l/100km combined
4.3 l/100km extra urban
6.5 l/100km urban

In real life I get:

6.2 l/100km combined
5.5 l/100km extra-urban
7.5 l/100km urban

That's driving style without any fuel savings in mind - I just step on it as much as I wish (and I wish a lot).

Car is 2.2 civic diesel.

It is possible however to reach manufactuers spec (at least on quite road outside city).
When driving at 80km/h constantly without any sharp accelerations and planning ahead, I was able to get 4.0 l/100km on distance of over 100km so it's actually better than manufacturer's spec. This driving style however was absolute nightmare in longer run, but interesting experiment.

Steve

Same as mine, the torque is what you paid for, can't just not use it

CiniO wrote: »

My car manufacurer spec is:

5.1 l/100km combined
4.3 l/100km extra urban
6.5 l/100km urban

In real life I get:

6.2 l/100km combined
5.5 l/100km extra-urban
7.5 l/100km urban

That's driving style without any fuel savings in mind - I just step on it as much as I wish (and I wish a lot).

Car is 2.2 civic diesel.

It is possible however to reach manufactuers spec (at least on quite road outside city).
When driving at 80km/h constantly without any sharp accelerations and planning ahead, I was able to get 4.0 l/100km on distance of over 100km so it's actually better than manufacturer's spec. This driving style however was absolute nightmare in longer run, but interesting experiment.

pa990

Quote: NIMAN
I'm getting just over 55mpg. My previous Ford Econetic was showing 61mpg, when I think Ford said it gets 72mpg.

Steve wrote: »

What's that in real units?

Mpg is the only true unit

pa990

Since the dawn of the motor car, manufacturers have been faking mpg figures.

I can get 60+ mpg with a BMW f10 520d n27, if I reset the trip computer (after the engine is at operating temp) while driving at 50mph on level ground.

But that means cruise control, no overtaking, no hills, no head wind, and no traffic.

Not really, real world conditions

Isn't it the EU setting the tests?

NIMAN

Steve wrote: »

What's that in real units?

That is real units...you can keep your litres/100km nonsense.;)

R.O.R

Changes to how the co2 is measured are on the way later this year for new models and next year for existing models.

It's going to result in higher co2 ratings so higher costs and is also going to mean that options can increase the co2 of cars, making everything a nightmare to price accurately.

I can hit or get very close to manufacturers combined figures on my commute so it is possible in the real world, just not for that many people.

Recent rentals............ over a week...... motorway and short spins over 400 ish miles......... indicated mpg

Tipo 1.4 petrol 42mpg
Fiat 500l 1.3 diesel 50mpg
Focus 1.3 diesel 54mpg
Astra 1.4 turbo petrol 38mpg
C4 Picasso 1.6 petrol 35mpg

They were all driven similarly.

My diesel Lancer averages 48mpg over the last 3 ish years.

_Kaiser_

pm. wrote: »

2016 3.0 tdi A4 quattro 8.1 Ltr per 100km 😦

My 2010 3.0 TDI Quattro A6 does much the same... usually into the 7's/100 over a 100km run on the motorway. Depends on how heavy my right foot is

millington

E39 530d auto

Parkers says 34mpg, real world short journeys is a little over 30mpg so I imagine it would do 34 on longer journeys. Not too far off anyway!

E46 320d 6 speed manual: Parkers 49mpg, real world 44mpg
E46 330d 6 speed manual: Parkers 42mpg, real world 41mpg

I suppose all of these cars are from an era where fuel economy was important but probably not pushed as much as it is now hence actually being close to the figures.

Cee-Jay-Cee

pa990 wrote: »

Since the dawn of the motor car, manufacturers have been faking mpg figures.

I can get 60+ mpg with a BMW f10 520d n27, if I reset the trip computer (after the engine is at operating temp) while driving at 50mph on level ground.

But that means cruise control, no overtaking, no hills, no head wind, and no traffic.

Not really, real world conditions

Cruise control results in higher fuel consumption, in my experience.

biko

I get 7L/100km motorway which is pretty much as advertised

Armchair Andy

For me the comfort of cruise control negates any gains in fuel economy.drive Dublin to Cork regularly at 39mpg at over 120kmh plus on cruise control

the_pen_turner

Cee-Jay-Cee wrote: »

Cruise control results in higher fuel consumption, in my experience.

why is that. you would imagine the cruise control would reduce heavy accelorating and breaking

the_pen_turner

the_pen_turner wrote: »

why is that. you would imagine the cruise control would reduce heavy accelorating and breaking

It does the opposite of efficient driving. By keeping constant speed no matter what it accelerates up inclines and idles on dips

pred racer

Cee-Jay-Cee wrote: »

Cruise control results in higher fuel consumption, in my experience.

In my experience its the exact opposite. My cruise control is way more efficient than me

Steve

NIMAN wrote: »

That is real units...you can keep your litres/100km nonsense.;)

Maybe in 1904..

Newsflash, we don't buy fuel in UK gallons any more or measure distance in UK miles - we have our own country now

pa990

Steve wrote: »

Maybe in 1904..

Newsflash, we don't buy fuel in UK gallons any more or measure distance in UK miles - we have our own country now

Anyone for 0.568 L / a pint ?


454g / 1lb of butter

Steve

pa990 wrote: »

Anyone for 0.568 L of beer ?

I prefer a large beer in France, you get a litre..

pa990

pa990 wrote: »

Anyone for 0.568 L / a pint ?


454g / 1lb of butter

I buy my Bulmers and milk by the litre just like my fuel

Leonard Hofstadter

NIMAN wrote: »

That is real units...you can keep your litres/100km nonsense.;)

Exactly. I have no idea what litres/100 km are, there is no easy way to convert from mpg to it like there is with miles and kilometres. Even then, I always do a mental calculation every time I see a sign with kms in it so I get distance into a unit I understand. I grew up with mpg, and that's what I'm sticking with. My car has mph clocks and everything is in miles, so even if I wanted to use this new fangled method to work out fuel consumption, it would be quite a palaver to do so.

CiniO

captainspeed wrote: »

Exactly. I have no idea what litres/100 km are, there is no easy way to convert from mpg to it like there is with miles and kilometres. Even then, I always do a mental calculation every time I see a sign with kms in it so I get distance into a unit I understand. I grew up with mpg, and that's what I'm sticking with. My car has mph clocks and everything is in miles, so even if I wanted to use this new fangled method to work out fuel consumption, it would be quite a palaver to do so.

Miles, galons, pounds, etc, are some archaic units originating from British empire.
Vast majority of the world uses SI units (i.e. kilometres, litres, kilograms, etc) and that's what we should stick to, as they make the most sense.

Most people in Ireland now drive cars showing distance in km and speed in km/h.

If you know that your car does 50 mpg it says you nothing.
If you know it does 6 l/100km, then if you intend to travel 200km, you know you'll need to fill up 12 litres.

NIMAN

CiniO wrote: »

If you know that your car does 50 mpg it says you nothing.
If you know it does 6 l/100km, then if you intend to travel 200km, you know you'll need to fill up 12 litres.

Of course it does, it tells you exactly the same as your 2nd statement.

If my commute is 50miles, then I know I'll need a gallon of fuel. Exactly same as your calculation, except using different units, units many of us grew up with. If you tell me your car does 5l/100km, I haven't a baldies if thats good or bad, but tell me your car does 55mpg and I'll know.

You'd be surprised how many people still talk in those old (Brit) units. Ask someone how far Dublin is away, and they are very likely to quote you in miles and not km.

Except that your fuel is sold per litre, not gallons

slave1

Honda CRV 1.6l diesel, advertised average 60.1mpg, getting ~56mpg

Steve

NIMAN wrote: »

Of course it does, it tells you exactly the same as your 2nd statement.

If my commute is 50miles, then I know I'll need a gallon of fuel. Exactly same as your calculation, except using different units, units many of us grew up with. If you tell me your car does 5l/100km, I haven't a baldies if thats good or bad, but tell me your car does 55mpg and I'll know.

You'd be surprised how many people still talk in those old (Brit) units. Ask someone how far Dublin is away, and they are very likely to quote you in miles and not km.

How much is a gallon of fuel these days?

Even the Brits sell it in litres now.

Maybe you should think in terms of quarts per rood, or cups per furlong.. they make equally less sense nowadays. No offense, I'm old too but the l/100km system is much easier to understand and quantify.

NIMAN

Deleted User wrote: »

Except that your fuel is sold per litre, not gallons

In the vast majority of cases it is sold by money, not litres or gallons.

Most people put in €20, €50 whatever, they don't head off to the petrol station to put in 15.76 litres.

Steve

NIMAN wrote: »

In the vast majority of cases it is sold by money, not litres or gallons.

Most people put in €20, €50 whatever, they don't head off to the petrol station to put in 15.76 litres.

Normally, I fill it, it costs what it costs and I don't fret over it, life is too short.. I then rely on the car to tell me the consumption.

NIMAN

Steve wrote: »

Normally, I fill it, it costs what it costs and I don't fret over it, life is too short.. I then rely on the car to tell me the consumption.

Exactly, me too.

My 2 cars tell me the consumption, one in MPG and the other in l/100km. To be honest, the former tells me more, but maybe thats just cos I am old. All the distances between places I travel to, I know in miles as I learned them when I was young. I haven't learned those in KM off the top of my head, but of course if I was interested I could do a rough calculation.

If many people were being honest, they would admit that if you said to anyone "what sort of mileage are you getting out of your car", you'll get an answer in mpg first.

yannakis

My consumption stats:
Honda Fit 2008 (1.3 VTEC - not the 8 sparkplugs DSI one) - 6.7-7.5 l/100km
Toyota Prius 2010 - 4.7-5.2 l/100km

pa990

Steve wrote: »

Normally, I fill it, it costs what it costs and I don't fret over it, life is too short.. I then rely on the car to tell me the consumption.

I fill to the brim with diesel from the cheapest and most reputable station on my travels.

But the readout on the dash is always set to mpg, even though the odometer is in km.


Not that many years ago, our cars were in mph, speed limits were mph, and directional road signs were in km.

Merry Prankster

Steve wrote: »

Normally, I fill it, it costs what it costs and I don't fret over it, life is too short.. I then rely on the car to tell me the consumption.

Do you mean using the fuel mileage calculator on the car, or measuring it yourself? I've just bought a Civic and the car states that I'm averaging 5.8/100km for the Wexford to Dublin run, but the tank suggests I'm not actually getting this fuel economy.

Steve

Merry Prankster wrote: »

Do you mean using the fuel mileage calculator on the car, or measuring it yourself? I've just bought a Civic and the car states that I'm averaging 5.8/100km for the Wexford to Dublin run, but the tank suggests I'm not actually getting this fuel economy.

Yes , I'm quoting what the car says.

Mine has two calculations, one for the current trip and one since you last reset the stats. The latter is fairly accurate imo.

Leonard Hofstadter

NIMAN wrote: »

Of course it does, it tells you exactly the same as your 2nd statement.

If my commute is 50miles, then I know I'll need a gallon of fuel. Exactly same as your calculation, except using different units, units many of us grew up with. If you tell me your car does 5l/100km, I haven't a baldies if thats good or bad, but tell me your car does 55mpg and I'll know.

You'd be surprised how many people still talk in those old (Brit) units. Ask someone how far Dublin is away, and they are very likely to quote you in miles and not km.

Exactly, it's actually very easy to work things out with mpg. If you reset the trip computer and trip meter every time you fill up (which I do), then you just multiply the average fuel consumption quoted by a sensible number... so if a car has a 60 litre tank, that's about 13.2 gallons, you just multiply the average mpg by 12 to work out when to fill up. By multiplying by 12 you're leaving an allowance for an over optimistic trip computer as well as not making the car run on fumes and sending sediment into the engine.

So, if a car has a 13.2 gallon tank and it's doing 40 mpg, I know I've got a range of about 480 miles and I know I need to think about filling up when I get to 450 miles... simples.

If a car has an 11 gallon (50 litre) tank, it's even easier, just multiply the average mpg by 10 to work out a sensible time to fill the car up, so if I'm driving a car with an 11 gallon tank and I'm doing 44 mpg, I know I should put fuel in it when the trip computer says I've done 440 miles since the last refill.

By contrast despite the supposed superiority of it, using l/100 km is not so easy, if a car is doing 7.3 l/100 km (whatever that is) then on a 60 litre tank I need to divide 55 by 7.3 to work out the range.... anyone willing to do that without a calculator?

In any case, my car can't tell me the average fuel consumption in l/100 km (or show distance in km) without going to a dealer and being specially coded to do so, so I'm certainly not going to ditch using miles and mpg any time soon!

robbie99

My car has a fuel gauge that tells me when to fill up.

Steve

captainspeed wrote: »

In any case, my car can't tell me the average fuel consumption in l/100 km (or show distance in km) without going to a dealer and being specially coded to do so, so I'm certainly not going to ditch using miles and mpg any time soon!

As I'm sure you are are aware, the Queen is partial to some Spanish marmalade on her toast. I'm sure you can work out now many of her miles and gallons it takes you to bring it to her....

bmwguy

captainspeed wrote: »

Exactly, it's actually very easy to work things out with mpg. If you reset the trip computer and trip meter every time you fill up (which I do), then you just multiply the average fuel consumption quoted by a sensible number... so if a car has a 60 litre tank, that's about 13.2 gallons, you just multiply the average mpg by 12 to work out when to fill up. By multiplying by 12 you're leaving an allowance for an over optimistic trip computer as well as not making the car run on fumes and sending sediment into the engine.

So, if a car has a 13.2 gallon tank and it's doing 40 mpg, I know I've got a range of about 480 miles and I know I need to think about filling up when I get to 450 miles... simples.

If a car has an 11 gallon (50 litre) tank, it's even easier, just multiply the average mpg by 10 to work out a sensible time to fill the car up, so if I'm driving a car with an 11 gallon tank and I'm doing 44 mpg, I know I should put fuel in it when the trip computer says I've done 440 miles since the last refill.

By contrast despite the supposed superiority of it, using l/100 km is not so easy, if a car is doing 7.3 l/100 km (whatever that is) then on a 60 litre tank I need to divide 55 by 7.3 to work out the range.... anyone willing to do that without a calculator?

In any case, my car can't tell me the average fuel consumption in l/100 km (or show distance in km) without going to a dealer and being specially coded to do so, so I'm certainly not going to ditch using miles and mpg any time soon!

Sorry, what? Do you not have a fuel gauge?

Starscream25

Fiesta econetic petrol. 1 litre engine
Claimed- 65.7 mpg - 3.6l/100km
Actual average - 47.88mpg - 4.88l/100km
Highest - 51.54mpg - 4.56l/100km
Lowest - 45.72mpg - 5.14l/100km

Achieving 72.88% of claimed mpg..........bastards.
Dashboard usually gives a reading ~1-2 mpg off.
Motorway driving, usually around 110km/h, ~40 miles a day

Lantus

Skoda 1.2 petrol. I can get 5.3 without much trouble. Goes up when I push it on motorways and drops if I take it easy. You can get 4.7 hyper mileing so for a petrol very happy. I do 100km a day. Cruise control always gets better results if you can use it but traffic doesn't help.

Lantus

Lantus wrote: »

Skoda 1.2 petrol. I can get 5.3 without much trouble. Goes up when I push it on motorways and drops if I take it easy. You can get 4.7 hyper mileing so for a petrol very happy. I do 100km a day. Cruise control always gets better results if you can use it but traffic doesn't help.

What's the advertised?

Lantus

Deleted User wrote:

What's the advertised?

Combined 4.7 and extra urban 4.0. Urban 6.0. The diesel model at the time was 3500 more. As well as being a bit of a noisy 3 pot it would probably of delivered a 1l/100km improvement if my mates diesel Skoda is anything to by. (4.5l/100km.) That's about 8eu a week or 400eu a year. After 8 years I'd of broken even and be saving money with the fuel efficient diesel at 100km a day 5 days a week. The Fabia is unusual in that regard as other models don't see such a price difference.

CalamariFritti

BMW 320D (F31) open road driving, doddeling along speeds, parkers 4.9 real 5.3 l/100km.

9935452

Starscream25 wrote: »

Fiesta econetic petrol. 1 litre engine
Claimed- 65.7 mpg - 3.6l/100km
Actual average - 47.88mpg - 4.88l/100km
Highest - 51.54mpg - 4.56l/100km
Lowest - 45.72mpg - 5.14l/100km

Achieving 72.88% of claimed mpg..........bastards.
Dashboard usually gives a reading ~1-2 mpg off.
Motorway driving, usually around 110km/h, ~40 miles a day

Small bit confused here
You are using a conversation rate to US MPG not imperial MPG
3.6l per 100km is more like 78mpg

Starscream25

Small bit confused here
You are using a conversation rate to US MPG not imperial MPG
3.6l per 100km is more like 78mpg

Apologies, it's fixed now, mpg is in imperial figures

Fiesta econetic petrol. 1 litre engine
Claimed- 65.7 mpg - 4.3/100km
Actual average - 47.88mpg - 5.9/100km
Highest - 51.54mpg - 5.48/100km
Lowest - 45.72mpg - 6.18/100km

Achieving 72.88% of claimed mpg..........bastards.
Dashboard usually gives a reading ~1-2 mpg off.
Motorway driving, usually around 110km/h, ~40 miles a day