real world vs ADR 81/02 fuel use over 8500kms

[Simonr23]

This isn't focussed on the tiguan, as opposed to all cars. it's only here, because my tiguan is the first car where i have actual data to reference against vs the little label on our windscreens (when new at the dealer anyway)

so my car is apparently 6.9l/100km @ 19kmh avg speed 'urban-. the test is 8mins with 13 stop/start instances, spending 30% of the time idling the rest slow accel and slow braking- to mimic peak hour traffic.

For the highway or ‘extra urban’ testing, my car is rated at 5.5l/100kmh at 63kmh avg speed (5min test, accelerating from stop a couple of times, up to a max of 120kph)

*** for reference, these test parameters are the same for every vehicle tested.

my actual figures are...


avg speed 20kph over a 15.5km route, which is 6km in a 80 zone and 9.5km on a straight 60kmh main urban road in Adelaide.
flat ground for the urban road, 1.5km of uphill for the 80kmh zone and 4.5km of flat/slight downhill for the remainder of the 80kmh in one direction, so reverse that info for the other leg of my daily commute.

11.5l/100km is my average. not quite 6.9... it's even worse if i use the TJA function(13.2 is my worst so far).


on the main road or 'extra urban' route i do semi-frequently (to the barossa valley), which is my work route, plus an extra 75kms each way. the average speed (during non-peak times) works out to about 65kmh- so close to the ADR speed again. my average for that 190km trup, over maybe 5 or 6 trips is 6.6l/100km.


so as is almost always the case, the official figures seem crap.



i love my stats, and it's been fun for me collating all the fuel use data (courtesy of my fuel card and the web interface for it) and the 'since start' feature of the vw's help too.

of the cars i've owned over the last 7-8 years (citroen c5, hyundai i45, fg xr6t, mazda 6), this one has had the biggest gap between my experience and the official stats.

usually i can achieve the tested highway figures be just driving normally and can be within about 15-20% for the urban cycle.


for anyone still reading, if i get a good run to/from work, i can get my urban average to as low as 9.5l/100km at about 28-30kmh avg speed

if i drive slow on the highway cycle i can get to about 5.8-5.9l/100km, but i'm driving at 'towing a caravan' speeds to do this- so not practical, or realistic.


does anyone else have good info to share on this topic?

cheers.

[doc_777]

Not sure what’s the point in comparing your consumption figures to lab-derived numbers which have no basis in reality. The sticker-numbers have never been represented by any manufacturer as achieveable in the real world - they are simply a government-mandated tool to supposedly assist consumers in comparing one vehicle to another.

comparing your real world numbers to the sticker number is about as useful as saying “I can’t get my vehicle up to the numbers at the top of the speedo because the police keep pulling me over - it’s false advertising by [insert vehicle manufacturer name]”

[Mozzz]

4 weeks in with my wolfie with pano roof ...using it all the time here in Brissie... loving the new car experience... 1200km done and 9.7 litres per 100km average so far ...have been driving gently ...2 trips per weeks of 25km into Brisbane city and back out again in peak hour, mostly 4- - 60kph on suburban roads - a couple of trips to Caloundra and one to the goldie from Oxley - 10km southwest of Brisbane CBD.

[Simonr23]

Sorry doc, I find this fun, that’s why I compare.

The data can be compared against cars. If two cars both claim Xl/100km, the theory is that they should both achieve Yl/100km in the real world, too.

I’m my case, my Mazda 6 had quite similar adr figures. In the city it was fairly close to the Tiguan- so good job vw- considering the extra weight of this car(300kgs)

But on the highway, the Mazda smashes the Tiguan (referencing their adr stats as a baseline)

As a key stat, I feel these tests should be tweaked to achieve results closer to those achieved when actually used on the road.

[doc_777]

Sorry doc, I find this fun, that’s why I compare.

The data can be compared against cars. If two cars both claim Xl/100km, the theory is that they should both achieve Yl/100km in the real world, too.

I’m my case, my Mazda 6 had quite similar adr figures. In the city it was fairly close to the Tiguan- so good job vw- considering the extra weight of this car(300kgs)

But on the highway, the Mazda smashes the Tiguan (referencing their adr stats as a baseline)

As a key stat, I feel these tests should be tweaked to achieve results closer to those achieved when actually used on the road.

Because there are simply so many variables, and because of the obvious confusion as to the purpose of these ratings, the methodology is being phased out in favour of Worldwide harmonized light vehicles test procedure - Wikipedia

Think hwy figures - relative air density increases massively as speed increases - and the Tiguan has a much larger frontal surface area than a Mazda 6 - so there’s one pretty big reason the relative numbers differ so much - and that (basically, wind resistance) is neatly not included in the current Aus test regime.

kinda like comparing apples and oranges

[Simonr23]

They actually do ‘allow’ for weight and drag apparently (cd figures I assume)

I’m sure it’s still quite flawed though.

My Mazda was claimed to be 4.8 on the highway. If I drove at the speed limit of 100kph and drove with the flow of city traffic, that trip could sometimes be in the high 4’s(4.6 on one trip where my wife drove).

If I do the same in the Tiguan though, the best I can get is about 6.2(vs 5.5 claimed)

The .7 more in the Tiguan is allowing for the drag and weight penalties the car has- presumably.

Something else ‘interesting’ is that only one model of a car is tested, the rest of the models have their figures calculated from the other car. They add/subtract fuel use based on weight/wheel/body shape changes only.

[miicah]

lol wtf

At 117 s, the car slowly accelerates to 50 km/h in 26 s (manual: 5 s, 9 s and 8 s in the 1st, 2nd and 3rd gears, with additional 2 × 2 s for gear changes)

You would be causing some serious road rage if you constantly were taking 26 seconds to get to 50km/h

[brad]

The rolling road test has resemblance to how we really drive.

I assume your 20km urban route is starting with a cold engine? The 11.5L/100 seems high, so I'm assuming cold engine and driving style influence with a small dose of less than ideal alignment settings thrown in. Do you also have your AC on?

Assuming your engine has 8500km on it, it isn't run in yet. Most VW engines seem to need 15k to start to loosen up.

[Transporter]

They actually do ‘allow’ for weight and drag apparently (cd figures I assume)

I’m sure it’s still quite flawed though.

My Mazda was claimed to be 4.8 on the highway. If I drove at the speed limit of 100kph and drove with the flow of city traffic, that trip could sometimes be in the high 4’s(4.6 on one trip where my wife drove).

If I do the same in the Tiguan though, the best I can get is about 6.2(vs 5.5 claimed)

The .7 more in the Tiguan is allowing for the drag and weight penalties the car has- presumably.

Something else ‘interesting’ is that only one model of a car is tested, the rest of the models have their figures calculated from the other car. They add/subtract fuel use based on weight/wheel/body shape changes only.

I wouldn’t bother too much with the decimal point, unles you precisely measured the fuel in the tank (always drained and pour calibrated amount in, for each vehicle test). Service station pumps accuracy fluctuate. You driving style has great influence on the fuel economy and maybe all other cars in the past you had we’re boring compared to Tiguan, so you enjoy driving it more.

I personally think that .7L/100km difference between real life and advertised fuel consumption is very good result. Every vehicle has the sweet spot at driving speed where you will achieve the best fuel consumption.

[brad]

I personally think that .7L/100km difference between real life and advertised fuel consumption is very good result. Every vehicle has the sweet spot at driving speed where you will achieve the best fuel consumption.

Indeed. My ex had a Captiva V6 that was supposed to be 11L/100 (or thereabouts) and we used to bop around getting 18-20L/100. We rarely drove it for economy but when we did it was 15L/100km at best.