125TDI Improved Fuel Economy After Long Drive.

[rory]

Found on my 1.6 litre TDI Jetta with DSG that lives in the country and almost invariably is sitting on 100 or 110 really drops consumption on a coastal cruise (no hills) and a tailwind ; down to 4.6 l/100k and once even 4.4 for a tank. Into wind it returns 5.0 on coast runs. I generally get 5 to 5.2 litres average per tank . 110 000 ks on the clock

[Diesel_vert]

Hi All,

Firstly, Merry Christmas.

I have just returned from a Christmas driving holiday to stretch the legs of wagon. The car had travelled 5500km prior to the road trip and was returning a fuel economy in the mid to high 6L/100km from mainly urban driving with the occasional freeway cruise to Mandurah which is 100km from Perth for a seafood lunch and to passive regen the DPF, just to be safe. No dashboard error lights ever illuminated.

On our 350km drive to Margaret River to sample the wines, , the car was showing 7.8L/100km. Not bad I thought considering there was 3 onboard, a fully loaded cargo area and the airconditioner working hard to keep us cool. There was a slight hesitancy on acceleration but nothing that I didn't put done to a near full load.

On the return trip, I brought back friend and his luggage, which added an additional 110kg to the weight and the temperature was even hotter peaking at 39C. To my surprise the fuel economy improved to 5.8L/100km and the car was pulling like the 3.0L Outback that the Passat replaced.

In short, it took 50L of Vortex diesel to travel almost 900km and the engine performance improved after a long run.

Cheers.

George

I'd say that's very normal.
The brochure states 6.7 l/100km for urban and 5.7 l/100km for combined, so your figures are pretty much bang on.

You will always use a lot more fuel in urban areas because of all the acceleration bursts, compared to steady state highway driving.

[sn809]

Most new cars dont match brochure stats as far as I know but that may just be me.

A suggestion either of you tried running with Morey's Diesel Engine Smoke Killer?? I did after reading up and getting advice from Transporter on VWW, does wonders for my old Passat. Read up and try.


Diesel fuel additives

[Diesel_vert]

As his car is still almost brand new and nothing much wrong with it, I wouldn't think he would need to use fuel additives at this stage.

[Transporter]

Hmm, I disagree. The deposits are formating and starting to clog the emission devices like DPF from the day one the engine is made and started up, so why wouldn't you help it to stay in peak condition for longer? Also, your DPF could last longer too.

But, ofcourse if you're rich enough and buy a new car every 3 years then why would you bother with some additive and better fuel economy.

Additives by LIQUI MOLY

[Diesel_vert]

The primary cause of DPF blockage is from accumulated ash, which is mostly derived from engine lubricant (metallic additives).

The amount of soot is of little concern because that is burnt off easily enough (for cars equipped with a DPF and assuming regeneration is able to be completed successfully).

In any case, being a Euro 5 vehicle means that the emissions devices are required to last for 160 000 km, so it will be a while before he should expect problems.

I just want to re-emphasise that there is absolutely nothing wrong with Amalgam's car and that it is normal for fuel consumption to decrease once you are on the open road, or increase once you go back into town.

[Transporter]

In any case, being a Euro 5 vehicle means that the emissions devices are required to last for 160 000 km, so it will be a while before he should expect problems.

Yes, I'm aware of that.
...and should any emission device in any of our rides fail before 160k km is up incl. turbocharger,
I will get them replaced free of charge by VW.

I just want to re-emphasise that there is absolutely nothing wrong with Amalgam's car and that it is normal for fuel consumption to decrease once you are on the open road, or increase once you go back into town.

I agree, see my earlier post in this thread.

[Marakai]

While you mention it: I'd been googling for diesel fuel additives to find out if they're worth it or snake oil. Unfortunately the answers are less than satisfactory: the majority of hits come from "reviews" by the manufacturers and *of course* show that they are the best thing since the microprocessor and ahead of sliced bread. Which I think I'll take cum grano salis.

Anybody have any pointers to independent evaluations of worth or worthlessness of additives? In a modern turbo-diesel, that is, not something from 20-30 years ago.

EDIT: herp derp, just saw sn809's link Though it doesn't really answer the question, apart from anecdotal VWWC evidence.

[sn809]

Two things are all I am going to point out

1. The standard of Diesel available in Australia is far worse than what is available in Europe, so although the tech is Euro 5 standard, the fuel is not.

2. VWW anecdotal evidence has saved me from quite a few issues and money, so I would rather believe it than what VW Australia says, also note it is just anecdotal evidence that says BP Ultimate diesel >Caltex Vorted>Shell. Most consumers will sear by BP Ultimate but there is no Ultimate diesel in a lot of the states. Also an issue is the servo you fill up from and how well they maintain their storage tanks (Diesel Algae maintenance) and weather the servo has a high diesel turn over or not (stagnant diesel). With so many variables Anecdotal is fine by me.

[Marakai]

By anecdotal I in no way implied "bad" or "not trustworthy".

In fact, this is more than timely: as by the time we get our Alltrack we'll be living in country Victoria, I most certainly will be away from BP-U or similar. So, I am keen on finding out which additives to use.

It's just that you'd think some consumer agency would have run some actual independent tests by now! Then we'd have a clear, say, CHOICE rating or some such.

Two things are all I am going to point out

1. The standard of Diesel available in Australia is far worse than what is available in Europe, so although the tech is Euro 5 standard, the fuel is not.

2. VWW anecdotal evidence has saved me from quite a few issues and money, so I would rather believe it than what VW Australia says, also note it is just anecdotal evidence that says BP Ultimate diesel >Caltex Vorted>Shell. Most consumers will sear by BP Ultimate but there is no Ultimate diesel in a lot of the states. Also an issue is the servo you fill up from and how well they maintain their storage tanks (Diesel Algae maintenance) and weather the servo has a high diesel turn over or not (stagnant diesel). With so many variables Anecdotal is fine by me.