2.0T FSI Engine??

[[TW]Fox]

There is a big difference between achieving 47mpg and averaging 47mpg and VW don't quote 47mpg as an average they quote 35.3

Read the OP of this thread

He was citing 47mpg as a benefit of the engine for him

 

[Dr Who]

Read the OP of this thread

He was citing 47mpg as a benefit of the engine for him

I read the OP, wouldn't it have been better to inform him of the fact he has misunderstood the MPG figures rather than pages of "you will never achieve that" which he actually could in isolation?

Sure he would have been better wording his post as "upto 47mpg economy in some circumstances" but people chose to question the accuracy of the manufacturers testing figure, rather than point out he had used the wrong one in his assumptions.

Then there was pages of rambling about how other people couldn't achieve manufacturers figures for their cars.

 

[[TW]Fox]

He presumed 47mpg is attainable because previously, you used to be able to attain manufacturers quoted extra urban figures on Motorway runs. The Extra Urban figure for my car, for example, is about 38mpg - which is acheiveable on a long Motorway run at the speed limit.

However the quoted extra urban figure for a 2009 530i is quite a bit higher, and I dont think they'd be attainable under the same circumstances.

 

[clv101]

He presumed 47mpg is attainable because previously, you used to be able to attain manufacturers quoted extra urban figures on Motorway runs. The Extra Urban figure for my car, for example, is about 38mpg - which is acheiveable on a long Motorway run at the speed limit.

However the quoted extra urban figure for a 2009 530i is quite a bit higher, and I dont think they'd be attainable under the same circumstances.

Yeah, this is the crux of the matter. I haven't driven a modern car for a while, I'll like to drive a ~2009 BMW and see just how things have changed.

 

[Jonnycoupe]

The Extra Urban figure for my car, for example, is about 38mpg - which is acheiveable on a long Motorway run at the speed limit.

However the quoted extra urban figure for a 2009 530i is quite a bit higher, and I dont think they'd be attainable under the same circumstances.

See that's impressive as extra urban is something like 37mph average with the motorway speed limit only touched on for 4 seconds.

Extra urban on mine is 94 IIRC.

 

[[TW]Fox]

See that's impressive as extra urban is something like 37mph average with the motorway speed limit only touched on for 4 seconds.

Extra urban on mine is 94 IIRC.

I think in the days before manufacturers began tuning engines so they'd perform exceptionally well for CO2 emissions on the test a happy coincidence existed whereby the results from the test matched what you could expect on a Motorway run.

Now everything is all about doing well on the test I dont think this is the case. Stop start for example makes a huge difference on the test yet no difference at 70mph..

 

[Sin_Chase]

Talking of tests.

*Looks at his cold start air pump*



I've never paid attention to quoted MPG figures, you'll get what you get and that will largely be dictated by driving style and where you are driving. No printed number on a piece of paper will get around the fact you either have a sippy cup 1litre or a 3litre.

 

[Dr Who]

He presumed 47mpg is attainable because previously, you used to be able to attain manufacturers quoted extra urban figures on Motorway runs. The Extra Urban figure for my car, for example, is about 38mpg - which is acheiveable on a long Motorway run at the speed limit.

However the quoted extra urban figure for a 2009 530i is quite a bit higher, and I dont think they'd be attainable under the same circumstances.

IIRC the predecessor to extra urban was constant 56mph?

 

[[TW]Fox]

That was absolutely years ago though - before any of the cars most of us drive, anyway.

 

[v0n]

Average of 63 km/h on 7 km run is the current EU extra urban cycle. But you can measure it from any point, it doesn't have to be cold start.

 

[Dr Who]

That was absolutely years ago though - before any of the cars most of us drive, anyway.

Don't think it was that long ago, late 90's? the other lower figure I think you may be referring to is the constant 75 mph? That was certainly achievable on a motorway drive.

The point is, the Urban and extra-urban tests are meant to account for typical journeys not constant speeds. They only allow for 4km and 7km distances being travelled, urban, being with a cold engine. Sure they arent going to cover every eventuality, and in some circumstances you can beat the quoted figures. If you drive at 56ish on a 60mph A-road you can batter the official consumption figures out of sight.

You pass comment about tests being about CO2 emissions, MPG is inextricably linked to CO2 emissions. If you make good MPG from an efficient engine, your CO2 emissions will be lower than a car with lower MPG. Engines aren't tuned for low CO2 emissions, they are tuned to be efficient during normal driving, and a lot of that does not include motorway driving. If you manged to achieve the constant 75mph fuel consumption figure, you can bet it was a lot worse than the constant 56 mph figure. Current extra Urban test is peak 75mph and average 39mph for 7km over half of which is conducted at a stead 56mph. It isn't meant to represent motorway driving, hence why you wont match it on a 75mph blast up the M5.

In summary, the figures are accurate, if you drive a journey like that simulated. If you expect to drive in a different fashion, you can expect better or worse, and with the way most people driver, it's usually worse.

 

[Dr Who]

Average of 63 km/h on 7 km run is the current EU extra urban cycle. But you can measure it from any point, it doesn't have to be cold start.

Urban cycle
The urban test cycle is carried out in a laboratory at an ambient temperature of 20°C to 30°C on a rolling road from a cold start where the engine has not run for several hours. The cycle consists of a series of accelerations, steady speeds, decelerations and idling. Maximum speed is 31 mph (50 km/h), average speed 12 mph (19 km/h) and the distance covered is 2.5 miles (4 km). The cycle is shown as Part One in the diagram below.

Extra-urban cycle
This cycle is conducted immediately following the urban cycle and consists of roughly half steady-speed driving and the remainder accelerations, decelerations, and some idling. Maximum speed is 75 mph (120 km/h), average speed is 39 mph (63 km/h) and the distance covered is 4.3 miles (7 km). The cycle is shown as Part Two in the diagram below.

 

[mjt]

would you care to provide a source?
not because i don't believe you, but i want to see the diagrams

why is extra-urban an average speed of 63km/h?
no wonder i get nowhere near this figure on the motorway. complete toss

 

[Dr Who]

would you care to provide a source?
not because i don't believe you, but i want to see the diagrams

why is extra-urban an average speed of 63km/h?
no wonder i get nowhere near this figure on the motorway. complete toss

http://www.vcacarfueldata.org.uk/information/fuel-consumption-testing-scheme.asp

That was my point all along, trying to compare the old Urban and constant 56/75 tests with the current Urban/Extra Urban figures is comparing apples and pears.

 

[mjt]

i wasn't comparing it to the old one, as it was before my time

now i understand why the extra-urban figure is a myth
the only way i can achieve it is by sitting at 40mph in 5th on a flat road for an infinate period of time.

 

[[TW]Fox]

That was my point all along, trying to compare the old Urban and constant 56/75 tests with the current Urban/Extra Urban figures is comparing apples and pears.

Nobody is trying to do that.

I was just saying that simply because he has been able to recreate manufacturers figures in the past does not mean he can count on 47mpg from a 2.0T.

 

[s0ck]

crap like a 170bhp diesel wont do 47mpg, i KNOW it will, ive done it!

I had to drive mine like a granny to get anything near that. I'd say my average was mid/high 30s. I've seen a few of the 140s hit their quoted with ease.
DPF to blame I suspect.

 

[Dr Who]

Nobody is trying to do that.

I was just saying that simply because he has been able to recreate manufacturers figures in the past does not mean he can count on 47mpg from a 2.0T.

I think tbh we are making the same point, I am saying you have to drive it extremely cautiously, and you are saying not with everyday useage.

As for 2.0 TDI's we are easily averaging over 50 with everyday use on the A3

 

[Dolph]

I think you are right to a degree, that some people do slow down to do other tasks such as answer the mobile, look at a map book, apply make up, but these are often the same people that usually drive at 80mph+ "they feel safer and pay less attention at lower speeds" is something we all have to contend with. However, knowing everyone else is a pillock is the first step to driving defensively, and that knowledge is power.

Whatever you may think about safety, the fact is, an accident at 60 will result in a lot less dmage than at 80. You have more observation time at 60mph and can take in more about the drivers around you IF you use that time effectively and dont lay back and think you are safe.

I think only something like 3-4% of accidents involving injury occur on motorways, they are already the safest roads to travel on. Statistically you are way less likely to be injured in an accident on a motorway at 60mph than you are at any speed on other types of roads.

I think we can all point out examples of bad road behaviour to prove our points or disprove each others, however, neither of us can argue the raw data or the physics involved with a crash at the 2 relative speeds.

No, but we can take it back to the correct point in the equation, which is not the risk of injury once the accident is in progress, but the changes in risk of an accident actually occuring, which is what we should be looking at.

Increasing speed from 60mph to 80mph does not increase the risk of being involved in an accident, as government funded studies continually show. Arguing that we should slow down as an alternative to actually tackling the causes of accidents makes no sense at all.

You as an aware driver, I am confident will spot the issues surrounding you and be able to take action in plenty of time and laugh them off. Others will be too busy on their hands free, eating a pie, balancing a coffee while they look for something to write on.

Quite, but that is not a reason to demand everyone slow down, but a reason to take action against those who are actually causing accidents. Place the blame where it is due and the problem will actually change, continue to place the blame on a false cause, and road safety will not really improve at all.

 

[Dr Who]

No, but we can take it back to the correct point in the equation, which is not the risk of injury once the accident is in progress, but the changes in risk of an accident actually occuring, which is what we should be looking at.

Increasing speed from 60mph to 80mph does not increase the risk of being involved in an accident, as government funded studies continually show. Arguing that we should slow down as an alternative to actually tackling the causes of accidents makes no sense at all.



Quite, but that is not a reason to demand everyone slow down, but a reason to take action against those who are actually causing accidents. Place the blame where it is due and the problem will actually change, continue to place the blame on a false cause, and road safety will not really improve at all.

Where exactly have I demanded everyone slow down?

No and being at 60 instead of 80 does not increase the risk of accidents either, so your arguement is invalid.

Therefore, if you are at 60, you have the same chance of an accident and the potential for less damage, ergo it is safer than 80.

I am not arguing people should slow down, I am saying, if you want to achieve better economy it is your choice, so please, just state you aren't willing to slow down, and let that be an end to a pointless arguement you created out of assumptions with no basis on fact. Depart the tall equine now.