Fuel Consumption - How's THAT going ?

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Originally Posted by Diesel_vert

The density of premium unleaded petrol (95 RON) is approximately 0.75 kg/L, so the difference in mass between a full tank and half a tank on a Mk7 Golf is 19 kg.

Assume a full tank is filled at $1.40/l, while half a tank is filled at $1.49/L (taken as the average of $1.40/L and $1.58/L). That is a price increase of 6.4%.

Therefore, fuel consumption must decrease by 6.4% in order to break even. Whether that will occur from carrying 19 kg less mass, I leave up to you to find out.

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Yeah this looks right, vw claim that a passenger can increase fuel consumption by 0.2l/100 so this would in all probability be almost negligible.

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Originally Posted by Diesel_vert

...it is difficult to justify purchasing the 2.0 TDI based on fuel consumption alone.

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There's a compelling second reason for a former Mk6 petrol owner: it gets you away from the 7 speed DSg and the petrol motor. Plus diesel is now cheaper than 98RON round Perth, and I'm looking a payoff round 80 000 km roughly for the price difference. Just had to fill the hire Passat, and it was $90 for petrol (95RON) and 750km, vs about $70 for diesel and 750km. Bigger tank and engine granted, but it surprised me nonetheless. $15 to $20 per tank is not insignificant.

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Originally Posted by adhock

Perth peak-hour/shoulder driving Mitchell Freeway, in a diesel wagon, my average when I try to watch it is about 6 l/100km. There's a hill at the end/start of the trip in East Perth that stuffs the figures every time. By the refill-at-pump figures (still only 3200 km on the car) it's 6 to 6.5/100km. It seems best when set to Eco mode and Coast whenever possible - accelerate modestly to a speed then coast until I need to catch up again. Pisses off the tailgaters tho. Better than the previous petrol Mk6 118TSI tho - it was about 7 to 7.5, no difference between 1st and 2nd engines (lemon alert).

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I've tried the coasting and don't really understand the benefit. Maybe it because I use the ACC a lot. Almost all the time. Most of the time when I'm coasting without the ACC I'm relying on the engine to slow the car. This uses no fuel. If I coasted the engine is still using fuel at idle speed.

I guess it's not much use to me because of the way I drive.

Maybe I just don't understand it properly.

After a weekend down at the ski slopes at Perisher Valley from Sydney, my long-term average went down from 6.9L to 6.2L :)

I started the thread about a year ago and I can now report that after 12000 k and my first service that fuel economy has settled to 5.4 l per 100 km. Mainly outer urban driving, some city. Mainly in economy mode. 90 tsi comfortline.
Just had the clutches replaced too !

Just filled up. 6.1 l/100km, at 5000 km, urban driving mostly peak hour freeway, diesel wagon. Can't complain.

I realise people don't buy GTI's for fuel economy but .......

I'm going from a Mk5 Comfortline (petrol 2.0L) to a Mk7 GTI (turbo petrol 2.0L).

Now we know the attractions of turbos is more power, more fuel economy ... but of course not at the same time :P

So my question is ..... if I drive my new GTI like an old fart (which I am :P ) could I approach or even better the fuel economy of my old car?

I used to have a 2.0T Quattro A3 and I averaged about 8L/100 mainly Sydney peak hour driving, with a stage 1 ecu upgrade. My wife's 2.0 FSI tiptronic mkv Golf Comfortline struggles to get under double figures...
So moral of the story is throttle control had a huge impact on consumption figures

I manage a displayed 9.5L/100km around town through Adelaide's rather subdued peak hour.
Drops into the low 8s when cruising more freely.

Hoping a tune up can make those numbers better (unless I hoof it!!)

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Originally Posted by Moonee

I realise people don't buy GTI's for fuel economy but .......

I'm going from a Mk5 Comfortline (petrol 2.0L) to a Mk7 GTI (turbo petrol 2.0L).

Now we know the attractions of turbos is more power, more fuel economy ... but of course not at the same time :P

So my question is ..... if I drive my new GTI like an old fart (which I am :P ) could I approach or even better the fuel economy of my old car?

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I am sure you can. It is there in manufacture data too,

for Mk5 Comfortline Triptronic - combined fuel economy 8.5L/100km (1328)
for MK7 DSG GTI - combined fuel economy 6.6L/100km

New engines are more efficient, less friction in moving parts and they run somewhat lean on freeway cruising situations (these turbo engines are build rugged). Also New GTI is lighter and more aerodynamically efficient and handles much better (so you don't have to brake each and every bend/corner you find on the road). Also DSG gearbox is more efficient than old triptronic system too. :)