MK7 GTD - Real Life MPG

[Skinnee D]

First 100 or so miles yesterday averaged 57mpg on the computer (having reset after collection though).  Mainly steady cross country driving with 10 miles or so at 70 on the motorway.  Not an onerous test but looks promising.
Using my Garmin GPS the trip counter was bang on for accuracy; the speedo only read 2 mph fast at 70.
Brimmed the tank last night for a "real" test...

[monkeyhanger]

To start my tuning box mpg experiment properly, I had to use a proper "control" and fill again with V-power to be assured that any gains weren't from filling up with normal Shell and not the doings of the TDI-tuning box. Did 183.9 miles on 19.83 litres = 42.5mpg vs indicated 44.0mpg: 3.5% optimistic, quite a change from last time when the disparity from indicated to actual was over 9% for my first tank. Maybe the computer has an accuracy "learning" period. It seems that this fill up vs last fill up is nowhere near as bad as I thought.

It will be interesting to know if any mpg gains are seen on the computer or only in brim to brim measurement because the MFD calculates MPG based on fuelling system signals sent by the ECU before the tuning system alters them.

[Misterp]

My car now has 1020 miles on the clock. Took it to Ellesmere Port on sat round trip of 150 miles got 55mpg on a 25 pound fill up. I'm think we are getting somewhere. This week mom through to tues I'm averaging 30mpg not pressed. I have it billed in for a knocking sound in reverse. I have asked them to look at the economy cos this is a joke.

[monkeyhanger]

My car now has 1020 miles on the clock. Took it to Ellesmere Port on sat round trip of 150 miles got 55mpg on a 25 pound fill up. I'm think we are getting somewhere. This week mom through to tues I'm averaging 30mpg not pressed. I have it billed in for a knocking sound in reverse. I have asked them to look at the economy cos this is a joke.

30mpg around the doors? What kind of commute are you doing? Are you getting lots of active regens caning your mpg? I’d hope not now you’ve cracked 1000 miles unless your commute is ridiculously short like 3 or 4 miles, the car is sat crawling along in heavy traffic all the time or you drive like a maniac.
 

£25 on assumption of £1.369 cost per litre of Diesel is 3.99 gallons. 150 miles over 4 gallons is 37.5mpg. 55mpg indicated I assume? Can’t see there being a disparity of the actual mpg being only 68% of MFD reading. How sure are you that your 150 miles swallowed up a whole 4 gallon fill? I reckon you’d have had some of that 4 gallons left. 55mpg indicated should be 49-52mpg actual depending on 5% disparity or 10% disparity. Take worst case actual 49mpg (from indicated 55mpg), you should have 0.92 Gallons left of your 3.99 Gallons doing that. 49 actual (55 indicated) mpg seems about what I would anticipate getting on a 150 mile trip maintaining 80mph, or thereabouts. If you were maintaining 60-70mph and only got that as well as your 30mpg around the doors then I would definitely say your car is abnormally thirsty. On clear roads, I’d expect to be pushing 60mpg (indicated) if I was maintaining 60-70mph on a 150 mile round trip. How is the traffic when you make your journeys?

[Misterp]

Stuck to 80 really not canning it at any point I like cruising    Around doors no traffic really (out of the ordinary)  but still pottering around town for about 6/7 miles is really bad for my mpg. And if the disparity is anything to go by it comes of as somewhat thirsty. It's booked in to get looked at tomorrow. I don't know how much light the 'master technician' can shed.

[Sootchucker]

Well, had my second fill up today (standard Shell Diesel).

MDF indicated an overall fuel consumption of 46.2mpg since last fill up. Filled the car to the second click of the forecourt pump (as I did last time), put in 42 litres (9.24 gallons) for 422 miles = a calculated average of 45.67 mpg (so the computer seems very accurate).

For the journeys I'm currently doing in crawling traffic and no long motorway runs, I'm pretty happy with that as my Rocco wouldn't have faired any better.

[monkeyhanger]

Now the temp has dipped, I don’t think my Scirocco would have fared any better than your actual. I’d be looking at a probable 50mpg indicated and 45mpg actual. Considering yours is a DSG (and should be 10% thirstier than a manual diven the same way), assuming we have a similarly economic driving style (you’re not driving like a nun, you accelerate quickly to cruising speed, but you do preserve your momentum as much as you can with good anticipation of the road ahead etc), you’re doing well. It will be interesting to see if a switch to regular diesel for me yields great improvement.

Seems quite honest of VW to make the computer more representative of reality. If they’d kept the traditional 10% disparity, most people here not interested in brim filling would have seen an instant “improvement” in their mpg vs previous gen. I bet your calculated average of 45.67mpg would have yielded an MFD indicated mpg of 50/51.

[Sootchucker]

I'm pretty much stuck in comfort mode at the moment, as due to traffic etc. there's no point for me in sport mode and nailing it for a couple of hundred yards between lights. I don't accelerate particularly quickly, but then not driving like a nun either - just, well, normal !

As the cars only got 850 miles on it as well, for the few motorway runs it gets (6 miles between 2 junctions), then I'm running at 75mph ish (not had it over 80 yet), and around the houses its just the usual applicable speed limits which I stick to as there are too many speed cameras around here. To be honest my whole commute (route, speed etc.) is the same as when I had the Scirocco. I always said if the GTD was as economical as the Scirocco but with an extra 30+ hp to boot then I would be delighted.

I've just looked at my fuelly account, and long term over 3000 miles in the Scirocco (unfortunately I only started by Fuelly account earlier this year) it averaged 45.5 overall. My GTD at just 850 miles and 2 fill ups is already at 44.3 mpg, and I expect this to increase slightly as the engine loosens up over the next few thousand miles (the Rocco was about 10% down on it's long term when new for the first 3000-5000 miles ish).

[stuart.cameron]

I'm pretty much stuck in comfort mode at the moment, as due to traffic etc. there's no point for me in sport mode and nailing it for a couple of hundred yards between lights. I don't accelerate particularly quickly, but then not driving like a nun either - just, well, normal !

As the cars only got 850 miles on it as well, for the few motorway runs it gets (6 miles between 2 junctions), then I'm running at 75mph ish (not had it over 80 yet), and around the houses its just the usual applicable speed limits which I stick to as there are too many speed cameras around here. To be honest my whole commute (route, speed etc.) is the same as when I had the Scirocco. I always said if the GTD was as economical as the Scirocco but with an extra 30+ hp to boot then I would be delighted.

I've just looked at my fuelly account, and long term over 3000 miles in the Scirocco (unfortunately I only started by Fuelly account earlier this year) it averaged 45.5 overall. My GTD at just 850 miles and 2 fill ups is already at 44.3 mpg, and I expect this to increase slightly as the engine loosens up over the next few thousand miles (the Rocco was about 10% down on it's long term when new for the first 3000-5000 miles ish).

Norbreck whats your fuelly account?

[Sootchucker]

Stuart, Fuelly is a website where you can log and upload your fuel consumption data, this then adds to a mean average worldwide for all similar cars and gives potential buyers of that car access to real car fuel data (rather than the manufacturers figures).

To be honest, I just use is as a record of my fill ups.

http://www.fuelly.com/driver/sootchucker/golf-gtd-184ps