Official Fuel Economy Thread (formerly Highway economy).

[jcubed]

Hi Sharkie.

I agree 100%. In all but the roughest conditions....

Now that I have fully co-operated with you, you may just concur that perhaps the word "all" is pushing it a wee bit ?

JJJ

[jimbomort]

An APR TSI Tiguan makes 189kw and 402NM of torque ..... more than 350NM of that is available from 1750rmin to 5000rmin ... imagine how that would go towing anything .... and at highveld altitude loses only 9% of power ....

Sharkie, I'm all the way with you of course on the APR'd TSI, and only a minor point, but where do you get 350Nm from 1750? From a curve for your car from Dyno testing? The APR stage 1 torque curve doesn't go below 2000rpm, I estimated from the APR graph that it would still be around 340nm (close) @ 2000rpm provided curve slope didn't change much, but all the way to 1750 would seem to be pushing it.

Interested in your source, happy to be proved wrong

Else gather on the differences in power losses above, that you are saying the forced induction copes better at higher altitudes than a normally aspirated car?

[jcubed]

Hi jimbomort,

Yes, power is lost as altitude increases due to the ambient air pressure dropping.

Standard atmospheric pressure at sea level is 1013.2mbar at 16°C. The rule of thumb is that you loose 30mb/1000ft. Therefore, at 6000 ft ASL - the highveld levels sharkie (who sounds like a home-boy) refers to - the ambient air pressure would be less by 180mbar.

That as a percentage of the ISO pressure above, would be 18%, so your power loss would be the same.

The first 180mbar of boost from a turbo puts this power loss back, and the car performs as at sea level, except for the initial turbo lag. The rest of the boost, say to 0.6 bar or so, adds performance. This is what is usually adjusted - the max boost level - when tuning, so that the pressure goes to ambient plus, say 0.8 or even 1 bar.

[Sharkie]

Hi jimbomort,

Yes, power is lost as altitude increases due to the ambient air pressure dropping.

Standard atmospheric pressure at sea level is 1013.2mbar at 16°C. The rule of thumb is that you loose 30mb/1000ft. Therefore, at 6000 ft ASL - the highveld levels sharkie (who sounds like a home-boy) refers to - the ambient air pressure would be less by 180mbar.

That as a percentage of the ISO pressure above, would be 18%, so your power loss would be the same.

The first 180mbar of boost from a turbo puts this power loss back, and the car performs as at sea level, except for the initial turbo lag. The rest of the boost, say to 0.6 bar or so, adds performance. This is what is usually adjusted - the max boost level - when tuning, so that the pressure goes to ambient plus, say 0.8 or even 1 bar.

Durban born, spent 10+years in Jhb ..... those years taught me the differences between sea-level & Jhb altitudes as far as power goes .... .... eventually gave up chasing normally aspirated power in Jhb and went forced induction and thanks to the current technology around all over never had to go back .... .... turbos are amazing things ....

BTW, have a look at my signature link, its got lots of GP number plated cars in it ...

[TiguanJo]

I have done just under 70,000 kms and the overall average is 5.9l/100 Last weekend I managed to do a trip from Rutherglen to Wagga at 4.8l/100. Simply amazing. I keep the car varying with the necessary boosts etc and definitely no 'lugging' I have the 2ltr TDI. I love it very impressed.

[team_v]

Done 1700km so far and the MFD reads 7.8l/100km
That is with an APR assisted TSI.

[yshsieh]

Run 6000km APR tuned TSI, 8 l/100km --> highway speed 100km/h

[Tedhaggie]

24000km . overall 7.6l/100km best 6.3l/100k

[ChrisJ]

24000km . overall 7.6l/100km best 6.3l/100k

wow jealous of all you guys, I only manage around 9s in my tdi. mostly inner city driving though. drops massively when just going to suburbs and highway.

[Transporter]

Ok, first fill up, MF display says 7.6L/100km and calculated from docket it is 7.79L/100km. Very happy with that since 50% of that were 20km trips in "S" mode up the hills to help engine run in.

[Captain Bungers]

I'm hitting around the 8.4L/100km for my 39 drive from the country into Canberra and back (each way) in my 125 TSI Manual. Have just cracked the 3500 km mark. It is a hilly drive with two overtaking lanes, so it gets a bit of a boot every now and then...

[mojo]

Driving back from Tamborine Mountain to Brissie a couple of weekends ago, I managed to get fuel consumption down to 5.0L/100km for the trip (according to the MFD). This was a trip of around 70km, mostly on 80km/h windy country roads and 100km/h freeway. I made a conscious effort to keep the revs in the range 1800 - 2000 when I was cruising on open roads. I also turned the A/C off for most of the trip. It actually got down to 4.8 at one stage, but crept up again when I hit suburban traffic. I suspect if I had been driving without putting much thought into it, consumption would have been around the mid to high 5's, which is still pretty good.

[team_v]

Driving back from Tamborine Mountain to Brissie a couple of weekends ago, I managed to get fuel consumption down to 5.0L/100km for the trip (according to the MFD). This was a trip of around 70km, mostly on 80km/h windy country roads and 100km/h freeway. I made a conscious effort to keep the revs in the range 1800 - 2000 when I was cruising on open roads. I also turned the A/C off for most of the trip. It actually got down to 4.8 at one stage, but crept up again when I hit suburban traffic. I suspect if I had been driving without putting much thought into it, consumption would have been around the mid to high 5's, which is still pretty good.

That is pretty decent work!
Lowest i have mangaed to get my Tiguan TSI on a trip average was 6.8


Went down the coast on Sunday with the Tig loaded up (5 adults and an esky and bags)
Managed 8.5l/100km due to some city driving at the beginning and end of the trip each way.
That is with a Stage 2 Tig (fuel economy does seem to take a hit, the same trip in a stage 1 would be 7.5-

[MGV]

Hi all, just did my 1st surf trip, Melbourne - Barwon Heads - Torquay & back. Did about 50 k's of city, 180 k's of freeway & about 70 or so country at 60-80kph. So around a 300k trip & averaged 7.8! Gotta be happy with that, with a board on the roof! Overall average after 3500 is 9.9, mainly city driving. It's a 125, BTW... Only other longish day trip was up to Mt Buller a month ago, averaged 7.8 on the way up, 7.7 on the way home (nothing on the roof). So it seems as though economy is hardly affected with something (smallish) on the roof.

Quick question: When you select 'Range' on the MFD, is the overall economy used to compute this value? I never seem to get what is displayed...
Another quick question: What would be a normal operational oil temp be? Cant find it in the book anywhere. I'm usually between 100 & 105.

[jimbomort]

averaged 7.8! Gotta be happy with that, with a board on the roof! ........averaged 7.8 on the way up, 7.7 on the way home (nothing on the roof). So it seems as though economy is hardly affected with something (smallish) on the roof.

great to hear you are enjoying it, as it runs fully in, if you drive economically you can get down to mid to high 6's on hwy trips. I'm surprised your economy wasn't better on the return though, as you would have had a net hill climb from Melb to Buller and a net descent on the way back, which alone can make quite a diff. Of course head winds etc also make a difference. The point I guess, is we cant always fairly compare the return trip with the outgoing.

I managed a 6.9 the other day and that was 'combined' driving. Was over 72klm, with a lot of errands in that trip, and banked stop/start traffic into town for a couple of kays. I also gave it the boot a couple of times, so could have been lower, but I was driving very much for economy the rest of the time. In fact I find in country towns my fuel economy often goes down. Cruising at 55-60klm in 5th gear, the spot fuel economy is often around 4.5-5.5 l/100. So you could even get down to 5.0l/100 in a TSI, albeit at 60klm/hr, which is completely unrealistic on long trips!!

Seems to me, dirven economically the TSI's, even those performance tuned such as Team V's and mine are quite good on fuel, but the TDI's driven the same, will always be at least 1.5l/100 better. So a tdi auto with air con on and a tsi manual without would be very close. Of course flip that the other way around and then the gap is then more like 2.5-3.0l/100.