Quoted MPG vs real world figures: BMW and Audi

[mrrossi]

Hi all

I'm trying to find the most economical, practical car (preferably a hatchback) for around £5K and have pretty much narrowed it down to a BMW 1 series or an Audi A3. It seems the competitors (Seat, Volvo, Skoda etc) can't quite produce as much power for the MPG.

Or at least according to official figures... the BMW 118d (older 122bhp version) supposedly gets 62mpg - the newer 143bhp should obtain the same figures but would be a bit out of my price range. Audi alledgedy can get 63mpg out of the 'eco' version of the A3 1.9TDI but I can't see many of them about - seems to be unclearly badged - and the standard model only gets 55bhp. As it's only got 105bhp too then surely I would be better off going for the BMW...

But then my girlfriend checked a Polish site she knows which lists 'real world' consumption figures in litres per 100km. I have converted to MPG and the results are:

BMW 118d (122bhp) 6.4l/100km 44.1mpg (average from 18 people)
BMW 118d (143bhp) 5.8l/100km 48.7mpg (average from 23 people)

Audi A3 1.9TDI (105bhp) 5.6l/100km 50.4mpg (average from 28 people)
Audi A3 1.9TDIeco (105bhp) 5.6l/100km (average from 6 people)
Audi A3 2.0TDI (140bhp) 6.3l/100km 44.8mpg (average from 66 people)
Audi A3 2.0TDI (170bhp) 6.7l/100km 42mpg (average from 11 people)

That wasn't expected! This suggests that the BMW figures are over optimistic and the Audi figures pessimistic.

The real world figure for the '62mpg' BMW is a dispointing 44mpg and the real world value for the '55mph' Audi is 50mpg, i.e. better than the beamer...?!?

If these figures are true then I might as well have the 170bhp Audi!!

Has anyone found this to be the case, that BMW figures are over optimistic and the Audi figures pessimistic?

Or could it just be chance that the 18 people driving the beamer are just all doing short distances, and that over a steady run (Nottingham to Coventry and back every day - 50 miles each way, mostly at 70mph, probably 20 mins at 40-50mph) I would be able to achieve the quoted 62mpg?

Cheers

Ross

[Dave Hedgehog]

there is a big website with 1000s of people logging their daily mpg, its dull so i do not remember the name thou

[Krikkit]

Dave Hedgehog said:

there is a big website with 1000s of people logging their daily mpg, its dull so i do not remember the name thou

Fuelly.

[anonymous-user]

In my experience, the car means virtually nothing and the driver everything...........

[P-Jay]

My Seat Exeo is meant to get 57mpg 'extra urban' whatever that is - gets 53-54 on a flat bit of motorway at a constant 70mph without roof racks on - also, despite what you might read online the trip computer is accurate to 'real world' usage +/- 0.5%.

So I'd suggest VAG cars are pretty honest.

I have heard most performance / efficiency stats for BMW's were to be taken with a bucket of salt?

[james_tigerwoods]

It's all about how you actually drive - I've got a 13 plate A3 2.0 diesel - I forget the quoted figures but in reality if I drive it in what I call a normal fashion and do about 80 on the motorway, 43-45 mpg is what I see on the trip computer.

Lately I've been showing a LOT of restraint and limiting myself to an indicate 74 mph, being a lot lighter on the pedal and keeping revs down as much as possible and 55-56 mpg is possible. Albeit dull.

On the plus side, I'm getting through my unabridged Lord of the Rings Audio book - now that's dull...

[gizlaroc]

UK FUEL FIGURES ARE TOTALLY AND UTTERLY FUNKING POINTLESS!

They mean nothing!

Not even good as a comparison against other cars.*

• Unless you drive everywhere at 33mph as they do in the test.

[xxChrisxx]

BMW put on a lot of technology to cycle beat, and in my experience it works relatively well in the real world.

Also BMWs typically have a relatively linear power delivery. The DERVs have been much nicer to drive than the old 1.9 VAG unit.

However the A3 is a more practical car than the 1 series.


At the end of the day, why are you bothering to base this decision on some numbers. Both are approximately the same size, do approximately the same economy, have approximately the same performance.

Drive both, buy the one you prefer.

[gizlaroc]

This is my 320d M-Sport Touring with 19" BBS CH wheels fitted and an auto gearbox.
It averaged 39.6 mpg pretty muhc every tankful.

As an experiment I decided to use a whole tankful sitting at 39mph to replicate the offical UK test.
I got 3/4 through the tank and had had enough, couldn't take it anymore, so took this pic to show what happens if you follow the test.




So, you need to try the car you want with you driving it how you drive it, offical fiugures mean fk all if you don't replicate the test.

X1 20d vs 18d.
The gearing is different but the same 2 litre diesel engine.

18d at 40mph sees 69mpg.
20d at 40mph sees 61mpg.

18d at 80mph sees 41mpg.
20d at 80mph sees 52mpg.

looking at the official figures the person who drives at 40mph is probably pleased with their 18d, the person who drives at 80mph is probably well and truly miffed.

[kambites]

In my experience, BMW are the best manufacturer at tailoring cars to the NDEC test.

[kambites]

gizlaroc said:

UK FUEL FIGURES ARE TOTALLY AND UTTERLY FUNKING POINTLESS!

They mean nothing!

Not even good as a comparison against other cars.*

• Unless you drive everywhere at 33mph as they do in the test.

What are "UK fuel figures"? And what part of the test is run at 33mph?

[gizlaroc]

Ren Esis said:

Surely that's around 500 miles for your 3/4 of a tank. How the hell did you manage that sort of distance at a constant 39mph

I was going back and forth to our place at the cost, it is 96 miles there and back using the cross country route, and I had to make 3 trips each day for 3 days moving stuff. So I thought that was a good time to try.
That was the second from last run and I had had enough by then!!
But better than being in the office.

[gdelargy]

mrrossi said:

Hi all

I'm trying to find the most economical, practical car (preferably a hatchback) for around £5K and have pretty much narrowed it down to a BMW 1 series or an Audi A3. It seems the competitors (Seat, Volvo, Skoda etc) can't quite produce as much power for the MPG.

Or at least according to official figures... the BMW 118d (older 122bhp version) supposedly gets 62mpg - the newer 143bhp should obtain the same figures but would be a bit out of my price range. Audi alledgedy can get 63mpg out of the 'eco' version of the A3 1.9TDI but I can't see many of them about - seems to be unclearly badged - and the standard model only gets 55bhp. As it's only got 105bhp too then surely I would be better off going for the BMW...

But then my girlfriend checked a Polish site she knows which lists 'real world' consumption figures in litres per 100km. I have converted to MPG and the results are:

BMW 118d (122bhp) 6.4l/100km 44.1mpg (average from 18 people)
BMW 118d (143bhp) 5.8l/100km 48.7mpg (average from 23 people)

Audi A3 1.9TDI (105bhp) 5.6l/100km 50.4mpg (average from 28 people)
Audi A3 1.9TDIeco (105bhp) 5.6l/100km (average from 6 people)
Audi A3 2.0TDI (140bhp) 6.3l/100km 44.8mpg (average from 66 people)
Audi A3 2.0TDI (170bhp) 6.7l/100km 42mpg (average from 11 people)

That wasn't expected! This suggests that the BMW figures are over optimistic and the Audi figures pessimistic.

The real world figure for the '62mpg' BMW is a dispointing 44mpg and the real world value for the '55mph' Audi is 50mpg, i.e. better than the beamer...?!?

If these figures are true then I might as well have the 170bhp Audi!!

Has anyone found this to be the case, that BMW figures are over optimistic and the Audi figures pessimistic?

Or could it just be chance that the 18 people driving the beamer are just all doing short distances, and that over a steady run (Nottingham to Coventry and back every day - 50 miles each way, mostly at 70mph, probably 20 mins at 40-50mph) I would be able to achieve the quoted 62mpg?

Cheers

Ross

I use spritmonitor.de/en, a German website which can be tailored to your local settings. It seems to have a larger database than whatever the Polish one is, and the figures are:

BMW 118d (122hp): 164 users, avg. 45.64mpg
BMW 118d (143hp): 619 users, 47.88mpg
Audi A3 TDi (105hp): 429 users, 50.04mpg
Audi A3 TDi (140hp): 699 users, 45.56mpg
Audi A3 TDi (170hp): 195 users, 42.85mpg

Despite all this eco technology, stop/starting etc, the size and weight of the car, and the approach of the driver are the biggest factors. All of these class of cars, whether they're Audis, BMWs, Kias, Fords, or whatever, will average 45-50mpg. You'll get anecdotal evidence to the contrary from individuals (i.e. someone getting 85mpg in their remapped 535d while lapping the Nordschleife in under nine minutes, until some PH diesel-hater comes along to say they got 90mpg in their 540i and a sub-8'30"), but with large sample sizes these are always the results you get.

[gizlaroc]

kambites said:

What are "UK fuel figures"? And what part of the test is run at 33mph?

Extra Urban.

Car fully up to temperature.
Ambient temp of between 18-26°c
4.5miles.
Accelerate to 70mph once and then slow down to average 39mph over the 4.5 miles, which means you need to slow tro around 32/34mph on 99.9999% of cars.

The combined figues is then worked out as a mean average of the above and the urban figure.

That is why, some people get batter figures round town than they do when sat on a motorway at 80mph.

Toyota Aygo - we got 50+ round town but sat at 80mph it was in the mid 40s revving its nuts off.


You have to buy a car that is geared to your driving if you are chasing MPG.


It's all bks though anyway.
I have gone from 40k miles a year to 20k miles a year and the difference between my 320d and the equivalent 330i was nothing, genuinely nothing. The 330i would do 38mpg on my run to the coast, the 320d would do 46mpg sat at the speeds I sit.

£119 week for the 330i
£102 week for the 320d

£1.30 petrol
£1.35 diesel.


That is a grand saving for £17 a week doing 40,000 miles a year.

If you only do 20k miles or even worse 10k miles is it really worth it?

[kambites]

My point was that they aren't "UK figures" except in that our government happens to use them for its taxation; and the car is very rarely run at 33mph.

To be fair to the NDEC cycle, it wasn't that unrepresentative until manufacturers started exploiting it. In most cars more than about ten years old, matching the official figures isn't particularly hard.

Edited by kambites on Thursday 17th July 15:51

[gizlaroc]

Now the USA is getting more diesels I look on their site for their City and Highway figures, these seem pretty bang on, when you convert back to UK gallons of course.

Take the Mercedes E250cdi

USA says 33mpg City and 50mpg Highway (converted to UK)

UK says 48mpg Urban and 66mpg Extra Urban.


Now which customer will be pretty pleased with his MPG figures and which one will come on PH asking "Is there something wrong with my car? Mercedes say that MPG is all I can expect in the real world."

[gizlaroc]

Interesting that the E400, the 3.5 litre V6 turbo gets 28mpg City and 36 Highway.

You can see why not many in the USA choose diesel when the official figures are that honest and not promising much more than a 10-20% by going for a 4cyl diesel.

[anonymous-user]

Have a look here:
http://www.honestjohn.co.uk/realmpg/

Real-world UK data submitted by owners.

[simo1863]

gizlaroc said:

I was going back and forth to our place at the cost, it is 96 miles there and back using the cross country route, and I had to make 3 trips each day for 3 days moving stuff. So I thought that was a good time to try.
That was the second from last run and I had had enough by then!!
But better than being in the office.

Much like the gentleman in The Lounge who performed the scientific test with frozen sausages in his lawn you have my complete respect.

Bet you annoyed loads of motorists though!

[gizlaroc]

simo1863 said:

Much like the gentleman in The Lounge who performed the scientific test with frozen sausages in his lawn you have my complete respect.

Bet you annoyed loads of motorists though!

Haha, the roads were empty the way I went, and no one really goes passed 40-45mph anyway.