I'm asking for a work colleague who has the aforesaid vehicle, with DSG gearbox, approx 14K miles (memory failing rapidly, mine) on the vehicle.
He's pretty sure it doesn't have a DPF, if those better informed know differently, please say.
My friend has owned this vehicle for about 8 months, he doesn't cover many miles, but the thing drinks diesel, he gets on average 38 to 40 mpg, he bought it used with very low mileage, one of a pair being offered through the dealership.
At the weekend, he did a motorway section on cruise at 70mph, and the vehicle was averaging only 37mpg at that speed, by the time he had covered a few more off motorway miles and got to his destination, he had just managed to get the average up to 40.
He has checked the fuel computer and is convinced its accurate, i assume by brimming and comparing.
Seat have had the car back and can find nothing wrong, but they do say that a customer who bought the sister vehicle to my friends is complaining of his fuel consumption too.
I assure you my friend knows how to drive economically and well, and with all his previous cars (Bora diesel last) he has easily beaten the published economy figures.
Thoughts please gentlemen.
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Is that a 2.0 140 or 170 bhp? If they fitted the 170, those figures fit with what I achieve in my manual Leon FR TDI with a DPF. Disappointing really compared to the published figures!
The 2.0 140 in SWMBO's Octavia Estate manual achieves high 40s mpg on a run at 80mph and mid 50s driven gently. And 32 mpg towing 1300kgs of caravan. A completely different kettle of fish!
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Nomag,
Its the 140hp, and he was expecting something like the figures you are getting from the Octavia.
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Assuming that the basics;
tyre pressures,
fitting of engine aerodynamic covers,
making sure the brakes don't drag,
checking the wheel alignment,... etc, etc.
have all being done, then,...
I speak from complete ignorance, and could be way off, but;
Is it possible for the 2 clutches in the DSG gearbox to fight each other?, i.e., for the one where the clutch is supposed to disconnected to actually be dragging?
One possible way to test this would be to run the engine at, say, 2000 rpm, and read the fuelling, via a tool like VAG-com, then, with the front wheels lifted, do the same in, say, third gear, and read the fuelling again. As there's no real load on the engine, I would expect the fuelling to be very similar. If there's any clutch drag, the extra engine load should be seen in increased fuelling. The results from this test would need to be compared against a known good vehicle to be useful.
Edited by Number_Cruncher on 14/08/2008 at 00:02
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I think that regrettably, this kind of fuel consumption figure is fairly typical of a VAG CAT IV diesel. I feel sorry for those who have had very good figures from their CAT III engines and have traded them for the later models. I don't think either VAG or the dealers have been entirely straight about the performance of this engine, (output or economy).
Testing for DSG drag by means of a comparative fuel consumption test with the wheels lifted sounds like a neat idea, but I once did a similar thing in the Lab many years ago (on a much larger diesel vehicle) and the drive train was nearly smashed to pieces by the undamped torsional oscillations. I wouldn't risk it.
659.
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drive train was nearly smashed to pieces by the undamped torsional oscillations. I wouldn't risk it.
Also ESP and TC systems might not allow it, i.e. for the front wheels to rotate at 3rd gear road speeds while the rear wheels are stationary.
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>>the drive train was nearly smashed to pieces by the undamped torsional oscillations. I wouldn't risk it.
That's not a problem that I've ever encountered when checking different small vehicle types for noise/vibration problems, and it's almost standard workshop practice. I've done similar tests many times, the only aspect I haven't done is the simultaneous monitoring of live engine ECU data.
I can imagine in a large vehicle you would have longer driveshaft lengths, larger overall gear ratio, and larger component inertias at the end of the driveshafts - i.e., the "free" resonant frequency of the driveline would be far lower than is the case in a car.
>>Also ESP and TC systems might not allow it
If that's the case, they can be simply disabled during the test. Again, not an insurmountable problem.
Edited by Number_Cruncher on 14/08/2008 at 12:55
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>>Also ESP and TC systems might not allow it If that's the case they can be simply disabled during the test. Again not an insurmountable problem.
A few years ago the dealer tried this with my Vectra which had a vibration problem, they could not work out why it would not rev while in gear on the ramp, I had to suggest that they turn off the TC !!!!
However I understand than many ESP system cannot be fully disabled and thus might not allow this approach.
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>>cannot be fully disabled
You can disable anything in a workshop!! Sometimes permanently!
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Just a thought - how much would it cost to measure the consumption according to the "official" test routine? If the measured value was below that quoted by the mf, would there be a warranty issue?
BIG
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Contact MIRA or there are a number of independent emission labs around the country that could do the testing but you would need one approved by the UK government.Likely to cost you more than the vehicle is worth.In Gemany,contact your local TuV laboratory.
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Sounds about correct to me, I've had a Seart Toledo 2.0 TDI 140 DSG for a little under two years now. It's done 18600 miles at never really goes above 38mpg on the motorway. Yesterday I achieved 47mpg over 30 miles at 60mph but thqat the highest i've ever seen.
TBH, I've been really dissapointed with this car and prefer to drive my old W202 C Class.
Simon
P.S the max I've had out of the tank has been 450 miles but on average its between 390-420 (motorway journeys) less if all around town.
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See also BobbyG's disappointing economy for this engine at
www.honestjohn.co.uk/forum/post/index.htm?v=e&t=65...6
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Same engine in 170PS form with DPF and DSG in my A3. Less than 40 is only ever seen when I'm doing urban stop start motoring, usually in winter. Last check was 46mpg - no fuel computer on my model.
These figures are in line with my last A3 which was a 140 with DSG but no DPF.
High motorway speeds sees mid 40s and low 50s is easily achieveable if driven carefully.
You say he doesn't cover many miles. Low mileage tootling round town is no good for these motors - they like regular motorway trips - mine does at least one 100+ mile motorway trip every month.
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Many thanks for the views and advice, i shall pass them on to my friend, by the sounds of it he's not alone in having poor economy from this engine in larger bodied models.
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I don't think he is suffering poor economy. He's doing low mileage and getting up to 40mpg - sounds about right to me. IIRC urban mpg for this engine/gearbox is about 37mpg.
A single one off motorway test won't tell him anything.
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Just to let you know.
My friend returned his toledo again, they could do nothing else with it, and have given him a good deal on another car.
He now has a VW jetta 07 with the same 140hp 2.0 diesel, but with the 6 speed manual and his first trip at the weekend (he uses his motorbike for short hauls/commutes etc anyway) saw him back to his usual 55mpg, so happy chappy there.
Thanks all.
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