Official Fuel Economy Thread (formerly Highway economy).

[BLWNHR]

Got an average of 8.6L/100KM.

...managed to average 6.3L/100km's.

Is this working it out properly (km travelled and litres at the pump), or using the in-dash display?

[Transporter]

Is this working it out properly (km travelled and litres at the pump), or using the in-dash display?

In dash display is somehow optimistic.
I found this as more acxurate:
Fill up the tank, reset trip meter, refill tank when it is down to 1/4 tank or less, (L used / km from trip meter) x 100 = L/100km

Here is nice software that will do it for you (Car organizer)

http://www.liqui-moly.de/liquimoly/web.nsf/id/pa_eng_home.html

[jimbomort]

In dash display is somehow optimistic.
I found this as more acxurate:
Fill up the tank, reset trip meter, refill tank when it is down to 1/4 tank or less, (L used / km from trip meter) x 100 = L/100km

dont necessarily disagree MFD may be wrong (especially noting my 5.8 in the petrol above), but I'd question whether the alternative proposed is necessarily more accurate. It is how much fuel you used, but with its own and potentially significant error margin. Unless you fill the tank to the exactly the same level each time you could easily be roughly 2 litres up or down either way (ie for 2 litres over - 1 litre 'under' at last refill, 1 litre 'over' when refilling to get litres used or vice versa)

You could stop when the pump stops each time, but doubt that is very consistent especially b/w different fuel suppliers and stations.

Does anyone know a reliable means of filling the fuel tank to the same level other than at the same pump at the same filling station to the same 'point', if indeed that works?

[Transporter]

dont necessarily disagree MFD may be wrong (especially noting my 5.8 in the petrol above), but I'd question whether the alternative proposed is necessarily more accurate. It is how much fuel you used, but with its own and potentially significant error margin. Unless you fill the tank to the exactly the same level each time you could easily be roughly 2 litres up or down either way (ie for 2 litres over - 1 litre 'under' at last refill, 1 litre 'over' when refilling to get litres used or vice versa)

You could stop when the pump stops each time, but doubt that is very consistent especially b/w different fuel suppliers and stations.

Does anyone know a reliable means of filling the fuel tank to the same level other than at the same pump at the same filling station to the same 'point', if indeed that works?

Hmm....then, more accurate way would be the long term fuel economy. Unless you want to drain the tank dry and measure the fuel you put in, drive as long as you have the minimum fuel in tank then drain it again to measure the remaining fuel. That will give you very accurate number. I like the long term fuel economy better.

[jimbomort]

anyone else doing mid 6's/100km in their 125 TSI

Hmm....then, more accurate way would be the long term fuel economy. Unless you want to drain the tank dry and measure the fuel you put in, drive as long as you have the minimum fuel in tank then drain it again to measure the remaining fuel. That will give you very accurate number. I like the long term fuel economy better.

agree, and a good test would be too compare the longer term value on the MFD over 4-5 tanks. Problem for me is I always drive more economically than my wife (well almost always) and she drives the car a lot during the week, so wont help me with getting a sense of whether the really good economy figures I have managed are accurate. No matter down to Sydney and back next week, so a good chance to check out the accuracy of the MFD then, hoping to make it to Sydney(about a 770km trip) on one tank with plenty to spare, which if we average in the mid 6's will do.

Is anyone else doing mid 6's on longer trips in their 125's?

[WannaTig]

Just did a trip up to NE Vic and back, got (according to MFD) 5.1L/km on the way up, and 5.9 on the way back. Loving it.

But is TDI, not TSI.

[Toner]

Our 103 TDI Tig has just about logged up 40,000 k of a mix of country freeway and town driving and the average varies between 6.9 and 7.1 l/100k. I thought it might drop even more once it got over 30,000k's but it doesn't seem to have altered

[jimbomort]

In dash display is somehow optimistic.
I found this as more acxurate:
Fill up the tank, reset trip meter, refill tank when it is down to 1/4 tank or less, (L used / km from trip meter) x 100 = L/100km

Well tested accuracy of the MFD on a recent trip to Sydney from northern nsw (755 klm). Did on less than one tank averaging 7.1 according to the MFD. That in itself was a bit higher than I expected from our TSI versus other trips we have done, but was concerned at start of that trip that the batch of fuel wasn't so good and more to the point this included 2.5 hrs of stop start driving (ie yeah really bad traffic at four points, meaning we covered about 50klm in that 2.5 hrs) plus driving in Sydney itself. Would have been in the high 6's at least without that.

Anyway MFD showed 7.1, 'actual' based on klms travelled and fuel refilled was 7.3. Noting of course that I have no way of knowing whether we filled up to same level, could have been up or down a bit either way. Tested MFD versus 'actual' on previous tank too and again same result, MFD was quite close just a bit on the low side - about 0.1 to 0.2 l/100klm lower. Will test again on way home, and over the next few tanks, to get the long term picture.

[jimbomort]

In dash display is somehow optimistic.

Further testing of our TSI is confirming that the MFD is optimistic by about 0.2 l/100klm - pretty close, but yes slightly optimistic.

Over 1439 klm, MFD is showing av of 7.4 and actual calculated av for the two tanks filled was 7.6. Will check over a few more tanks to confirm but at every comparison so far has been consistent - 0.2 under actual.

On recent return from Sydney (to Port Macquarie) averaged 6.6 according to MFD, so estimate actual was 6.8. This over 365klm, with about 50klm of urban driving in that, air con on and driving at steady 100klm hr on hwy.

Actual av for a combo of Sydney city driving and hwy driving for a total trip of 640 klm was 7.9l'100klm. That was 50:50 urban and hwy, with a fair bit of flooring it in the city as was showing brother and friends what the Tig can now do with APR stage 1 upgrade (they were very impressed despite high expectations). 7.9 is pretty good, and way below the 9.1 combined fig quoted for a mix of both (though I dont know based on what city conditions or the proportion of each). It also confirms for me that an actual of 6.8 is about right, as @ 50:50, average in city driving couldn't be more than about 9.0l/100klm for an actual average of 7.9 over the total distance.

According to MFD last leg - Port to Far northern NSW was av of 7.5, quite a bit higher than day before, but I cranked the cruise up to 110 (100 the first day), we stopped more and I did a lot more overtaking with the higher av speed and a stronger cross wind.

The Air con makes quite a difference, at least 0.5 litres per 100 from what I can see.

[donweather]

The Air con makes quite a difference, at least 0.5 litres per 100 from what I can see.

This may explain why I can't get anywhere near your figures, even on the highway. I have the aircon cranked to "LO" ALL the time. The best I can get out on the highway at 110 (although perhaps this isn't 110 based on the other thread) is about 8-9l/100km based on the MFD display.

[jimbomort]

This may explain why I can't get anywhere near your figures, even on the highway.....The best I can get out on the highway at 110 ..... is about 8-9l/100km based on the MFD display.

Don yeh having air con on all the time would certainly make a difference, but so will approach to driving - I am enjoying driving economically, its more relaxing and feeling I am doing my bit, but its not for everyone nor even for me all of the time - I like to use the performance I now have with the APR stage 1 upgrade.

It's worth mentioning that my wife's consumption in the same car is generally significantly higher than mine (at least 1.0 l per 100). In getting in the 6's, I am:
- cruising steady at 100
- not using air con or managing the air con (ie using air con on descents and flats, but turning off during significant ascents or acceleration)
- turning engine off at traffic lights/where I stop and dont expect to be moving again for at least 30-60 secs (less important for hwy trips but does make a significant diff in city driving or in my case above where I was stuck in a lot of stop/start traffic on way down to Syd)
- using 5th gear in 60 zones (which car copes with quite well - I often find my fuel consumption improves when I go thru towns !!!)
- anticipating traffic flow, so reducing amount I am braking and accelerating (wasting energy) and so if coming to a stop/slowing down using engine compression to do most of the slowing rather than the brakes where I can
- accelerating more gently (in 2nd as soon as car is moving, in 3rd @ 30, in 4th @ 45-50, in 5th @ 60-65, in 6th @ 80-85), the turbo kicks in around 2500rpm so changing up then or before helps and from 1500 rpm the car has plenty enough torque as long as you dont expect brisk acceleration

Done consistently these things make a big difference. What I have also found is that now, applying these practices when I dont need/want to use the power, means that even when I do use it during the trip, my overall average is still reasonable (such as the 7.5 above) and shot into town to pick up a pizza last night - a return trip of just 5 klm, in which I floored it twice in second from 20 right up to 80 ( its just so much fun and there's a short 80 zone on way in) and I still got an indicated 8.0l/100 on that trip, noting this wasn't from a cold start, engine was already warm from a recent trip.

Anyway hope this helps, driven economically the petrols are not that far behind the diesels on economy.

[Sharkie]

I never drive with fuel economy in mind .... .... in fact I'm enjoying the 200odd kw I have at my disposal so much that for the last 3 tanks I've been getting about 400-450kms per tank ......

Expect to do a nice longish trip this coming weekend to see what I can coax out of it if I stay off the accelerator ....

[jimbomort]

I never drive with fuel economy in mind .... .... in fact I'm enjoying the 200odd kw I have at my disposal so much that for the last 3 tanks I've been getting about 400-450kms per tank ......

As long as you are enjoying it Sharkie, thats about half of what we are getting out of a tank.

However I suspect even for those who do enjoy a bit of spirited driving, or bucket loads of acceleration from time to time ( yeh baby) that in everyday driving there are a few who might like to do better. This thread is more about that - be interested to here how you go on a longer trip.

[Sharkie]

As long as you are enjoying it Sharkie, thats about half of what we are getting out of a tank.

However I suspect even for those who do enjoy a bit of spirited driving, or bucket loads of acceleration from time to time ( yeh baby) that in everyday driving there are a few who might like to do better. This thread is more about that - be interested to here how you go on a longer trip.

My consumption is about as bad as you are going to get in a Tiguan, considering I drive it as hard as is legally possible..... all the time. Average since taking delivery is 12.3l/100km (MFD) and over 3100km (yes that is all and its 6 months old) its been in the city except for 400km ......

Considering the way its been driven and the power it makes, I am more than happy with that .....

Thought it would be good to get the opposite extreme out there .....

[clip]

My consumption is about as bad as you are going to get in a Tiguan, considering I drive it as hard as is legally possible..... all the time. Average since taking delivery is 12.3l/100km (MFD) and over 3100km (yes that is all and its 6 months old) its been in the city except for 400km ......

Thought it would be good to get the opposite extreme out there .....

...and I thought I had a heavy foot 9.8 is worse I've been able to get in 30,000k's (it's 11 months old now!).