Fabia 1.6 CR TDI 90bhp appalling fuel consumption

[xreyuk]

http://www.honestjoh...ufacturer=skoda

That honest john website is crap. I don't trust it one bit.

Also:

http://www.telegraph.co.uk/motoring/new ... -boss.html

Too right

[MikeHart]

Hello again everyone.

Thought I'd add some information from my meeting with an 'expert' from Skoda Technical in Milton Keynes (specialist subject engines). I was asked to attend on a given date with the car for this consultation, which I was lead to believe might involve an inspection and certainly a drive with them. In reality, he turned up fully suited and booted and with one intent, to persuade me I'm wrong and the car is actually OK.

Unfortunately, he failed miserably on this count and has if anything, persuaded me they are trying too hard to explain everything with preposterous, rubbish claims and therefore it must actually be faulty, but in a way they don't want to admit.

Let's start with the shaking during regen at idle (1000rpm). According to him, 'uneven running' is a characteristic of this situation and therefore the shaking/shuddering I get is perfectly normal. In fact, he stated that every one of them does this. In fact, if you don't get it, that's more of a worry. I did point out the exact nature of it, the changing rpm, the near stalling and the violence of the shaking, but he would hear nothing of it. In his own words, if you have a car that DOESN'T do this, it is not working to specification, i.e. faulty. He explained most people not reporting it and saying they never even notice a regen by saying they are either very unobservant, or they feel it, but assume it's normal and therefore don't report it!! Seems quite insulting to their customers. I've had various people in my car during this occurrence and not one of them has failed to express alarm at what was going on. If this really is normal, clearly VAG have lowered their quality standards enormously.

Second issue. My car sometimes shakes (similar to the regen issue above) when simply idling and not doing a regen. His explanation for this........ Either, it is thinking about doing a regen, but then decides not to, or the engine management system has got the tuning wrong (similar to a person adjusting an old fashioned choke wrongly). So,in a desperate attempt to ignore my symptoms, he's actually suggested an engine management system error!! Incorrect coding etc. of the program!! Simple answer........he doesn't have an answer, but all the tests say it's OK, so it must be.............

When asking why my wifes 2.0TDI Ford Galaxy and managers 2.0TDI CR Passat both can achieve significantly higher mpgs than my Fabia (when driven by me the same way), he gave me an explanation. I'm no engineer and maybe someone better qualified on here could respond, but it smelt of bulls**t to me. Basically, if a car takes 50hp to maintain a given speed and the engine produces 100hp (1.6 engine), it will be running at 50% loading. If it actually produces 200hp (2.0 engine), it will be running at 25% loading. Therefore, as the loading is lower, the 2.0 will produce more mpg. I said, doesn't that mean that bigger engines are always better? More hp when required and better mpg when cruising? He said yes. Now, as I said, I don't know much about engines, but I do know that just about every manufacturer is producing smaller and smaller engines to achieve lower emissions, better mpg etc. Therefore, his comment and logic appears to fly in the face of where everything is going. Indeed, the Ford Focus is available with a 1.0litre engine now!!

He was absolutely floored by the huge drop in mpg after a regen and the gradual climb until a maximum at the next regen, before falling again. He couldn't explain this at all, but did accept that it seemed the reverse of what he would expect to see. I didn't push it, so he didn't come up with any explanation. He also stated that people suggesting keeping the rpm high (say over 1500rpm) was incorrect, that all their advice said you should change up early, accelerating gradually etc. Effectively as the gear change indicator says.

The changing feel of the car (sometimes eager, sometimes very sluggish) were explained as being related to air temperature and air density. Now, I can understand these could make a difference, but I've never had a car before that has shown differing performance according to temperature and density. Apparently, the engine management unit attempts to give the same feel all the time, but doesn't always succeed. Whilst accepting that changes in the air will make some difference, I find the scale of the difference to be beyond what I would have thought would occur.

Finally, when I complained about getting about 55mpg at 55-60mph, he stated this was actually quite good. The average figures received by Skoda are apparently between 48 and 52mpg. I looked on the Honest John website (not necessarily the best, but handy) and even they suggest a range of 50-66mpg with an average of 58mpg. I wish!! It was higher than this, but I suspect entering my numbers lowered it somewhat!! Interestingly, my Toyota Yaris figures are towards the top of the Honest John range for that car.

There was a lot more to the discussions (it lasted 3.5 hours), but I was deeply unimpressed and came away with the impression he would do anything to deny accepting my car has a fault. Both the journey home the day before and the journey to work the following day were accompanied by the car shaking when sitting at idle and not regening. I get the distinct impression that Skoda (and probably VW) are well aware of this problem and probably even know what it is, but don't want to admit it. Very similar to a recent PD injector problem that they've been forced to accept recently.

Interestingly, over the last few days, I have come to my own possible conclusion. I'm not sure if anyone on here knows the answer, but you never know. Where do the air temperature readings displayed on the console come from? Is it the same source as used by the engine (say air inlet temperature)? The reasons for asking........the figures being displayed are substantially different from reality and I would have thought if they were used for the tuning, could affect things and result in inaccurate mixes etc. I have also noticed that the shuddering at idle (no regen) has only occurred in relatively hot (for this country anyway!!) weather.

[Wilko251088]

You say 58 average taken off of honest John, but you only get 55 average? That's only 3 miles out (not that bad in my eyes) or am I missing a point here?

Edited 21 May, 2012 by Wilko251088

[xreyuk]

Honest Johns average mpg thing is a load of crap.

[MikeHart]

You say 58 average taken off of honest John, but you only get 55 average? That's only 3 miles out (not that bad in my eyes) or am I missing a point here?

I don't know how good the figures on Honest John are, but given they range from 50-66mpg and the profile of my journey, I would expect to get very close to the top. It would be difficult to get a better journey than mine for fuel economy, especially as large parts of it match the extra urban profile used for the tests!! The extra urban figure for my car is way into the 70s. So, 60-65mpg should be quite generous to Skoda.

The whole impression I got from the 'man from Skoda', who was supposed to be a technical expert on the engine, was that he would do and say anything to deny a problem. If my impression is correct, this suggests they know what the issue is, but don't want to acknowledge it. Given the VW issues with injectors on some 2.0TDI PD engines recently and being forced to admit the design fault even after they've forced lots of people to pay for the repairs themselves, it's rather interesting. Gives the impression that VW have been trying to hide and deny problems. That's exactly the feeling I got from the conversation. Given that it was clear he was only interested in a conversation, I rather wish they hadn't wasted a day of my annual holiday as well.

As many people on here have said, Skoda service is absolute rubbish. A great shame, as I'm told it was very good. And no, not all are the same. I've had very good service from both Ford and Toyota in the past, although some is around the dealership rather than the manufacturer.

[MikeHart]

Honest Johns average mpg thing is a load of crap.

Would you like to qualify this? I have no idea how good it is, but just saying it's crap without reference is rather pointless.

[xreyuk]

So, I finally think my MPG problems are solved!

This was an 180 mile round trip up to the Barrow in Furness (Lake District) and back. I did about 70% motorway driving. I had a full tank of fuel (filled up at the start of the journey) a very heavy boot, equivalent to a full load of passengers (lots of heavy equipment) and did 70mph on the motorway the whole way on cruise control. Had I been doing 60mph I think 75mpg would have been achievable and I think in an empty car, 80mpg might be achievable.

Before anyone tries to rain on my parade about my trip computer, on every tank I have owned the car, it has UNDER read by 2mpg over a whole tank :p

So, what do I think the problem was?

I noticed that whenever I started the car cold, and brought it up to temperature, it never reached the full efficiency of when the engine was started hot. I was resetting the trip, so NO COLD ENGINE DRIVING WAS INCLUDED.

If I started the engine cold, and reset the trip computer when it got warm, I'd get around 50mpg urban, and 55mpg on the motorway. If the car was started warm, I'd get about 55-60mpg urban and about 63-65mpg on the motorway. I'd also noticed it lacked about 20BHP when started cold and brought up to temperature, until it was stopped.

I thought there may have been a problem with a sensor, or the thermostat, so used Vag Com to monitor the coolant temperature, oil temperature, and coolant temperature as it left the radiator.

Sods law would have it, for the very first time I owned the car, when I tried to scan it, it started properly, and reach full efficiency and power. Now for whatever reason, it seems Vag Com must have kicked something into gear, because ever since I've scanned it, I've seen around a 8-10mpg jump in my fuel average, especially at 70mph, and 30mph.

I know some people will just say it's the engine loosening up, but it literally wouldn't change that much overnight if it was the engine loosening, and I think somehow Vag Com has had an effect on a reading somewhere, and has kicked it up the arse.

Hopefully, fingers crossed, it's fixed now, and I just need to get a whistling noise investigated and my windscreen replaced and I'm good to go!

For the first time since I've owned the car, I'm REALLY starting to enjoy it.

[pearce_jj]

...experimented with various driving styles including never drop RPM below 2K unless car is coasting...

To be fair this is actually bad advice - lower RPM is always more efficient - think about it.

Also there are always production tollerances. For example I have a Fabia TSi/DSG and a Roomster TSi/DSG. On paper the Roomster uses more fuel - but in practice it's always a few mpg ahead of the Fabia despite being bigger and heavier. Yesterday in the Roomster I did a 180 mile round trip and the average (per the display) was 56mpg. The best I've had out of the Fabia is about 52 mpg.

[Guest]

To be fair this is actually bad advice - lower RPM is always more efficient - think about it.

Well, not always true. It depends in what context you are speaking about it. Revs that are too low for the gear and work load being experienced by the engine will always cause lower mpg whatever the engine/vehicle. These cause more stress and load on components and the engine burns the fuel less efficiently and more of it to boot due to larger throttle openings being used. That's a proven, and will, if always driven like that shorten the engines life, also proven. Production tolerances are very well controlled normally and don't vary very much. Not usually enough to make any real difference to the performance of an engine, but there are some exceptions as always. But I think I see the point you are trying to make.

[io1901]

Recently I've been getting even better mpg in the Octavia in the warmer weather and I'm not far off the claimed combined 68.9mpg (on whatcar!) and have been able to exceed the extra urban of 80.7mpg on a couple of occasions. But I have noticed if I have to drive home "through the lanes" rather than on the motorway I'll struggle to get 60mpg.

[delta925]

To be fair this is actually bad advice - lower RPM is always more efficient - think about it.

Also there are always production tollerances. For example I have a Fabia TSi/DSG and a Roomster TSi/DSG. On paper the Roomster uses more fuel - but in practice it's always a few mpg ahead of the Fabia despite being bigger and heavier. Yesterday in the Roomster I did a 180 mile round trip and the average (per the display) was 56mpg. The best I've had out of the Fabia is about 52 mpg.

Certainly there is less friction at 2000rpm than 3000rpm however if the revs are too low the turbo will be giving no or limited boost when the engine will run less efficiently. There is a post somewhere on this forum but if I recall right it is under about 1800rpm when the lack of boost is significant. Hence why lower mpg keeping at around 1500rpm than close to 2000rpm and the comments to ignore the gear change prompts because the engine revs they trigger at are too low.

[seboni121]

Agree this engine does not like sitting under 15/1700 rpm turbo needs to be spinning to get the fuel economy I've got the 105 in the golf and it's the same as the fabia with the same engine, however the ecu in the golf makes it a little better responsively IMO

[xreyuk]

I personally run the engine between 1,500 and 2,500 RPM. I have the ecomotive version, so longer gears means that if I change at 2,500RPM, it drops me at around 1,500RPM.

[pearce_jj]

On power it may be true (higher compression), but trundling along on the flat say 30 or 40mph the power requirements are so low that surely pumping losses must be more significant?

[lemonvrs]

I just covered 400 miles, a mix of motorway and A roads plus 3 days commuting in heavy traffic. The motorway trips had the car fully loaded in the back with stuff and its returned 55mpg... thats a Roomster 105 so Im happy.

I find if I drive at 1500rpm with a very light throttle I can get over 70mpg, driving the same but at 2000rpm sees that drop to low 60s. At least a couple of times a week, when shes fully warm I drive it like I stole it!

[percymon]

I now have 50k miles on my 1.6 TDI 105 Golf.

Anyone who wants to see my fuel records can see them on my fuelly account (well the last 35k miles anyway)... http://www.fuelly.com/driver/Percymon/golf

I've never had the burning smell, and i've never had any shakes during regens - in fact other than seeing poor mpg on my normal commute about once every 20 journeys or so I'm not aware of any regen.

I've seen a single journey best mpg of 76.0mpg, and several in the 70-74mpg range - all decent length country A road trips sticking to 50-55mpg or lower speed when speed limits dictated. My 27 mile commute is 24 miles dual carriageway and with the cruise set on 61mph (tomtom says this is 57mph for reference) and one a dry day with no stops at roundabouts/junctions i can see 65mpg, but with one or two stops it drops to 63,pg. Add in rain / wet road and these figures drop by 3-4mpg.

My optional 17" alloys and 225/45/17 tyres are ridiculously heavy (thanks VW !), and when i swap to my winter steel wheel and 195/65/15 tyres I see 10% btter mpg on the same journey and driving style (two winters, one freezing cold, the other relatively mild have shown this consistently).

I can't say i'm overly impressed - the price of fuel at it high started me driving a lot more conservatively and i've become a little bit of an economy junkie (coasting into roundabouts etc).

I accept the car is a lot heavier than my previous 90bhp 1.9tdi Mk 3 Golf, but that car could do 55mpg being thrashed and had a lot more urge for overtaking on A and B roads. Overall, the Golf is pretty refined and hasn't really given any issues in the 50k miles (bar a high pressure fuel pump failure = breakdown) so I suppoe i shouldn't complaint oo much - but as with this engine in every other VAG model driving at or over motorway speed limits really kills the mpg, and lots of hard throttle use won;t see much better than 45mpg.

[punyXpress]

Interesting what you say about regen - wonder what figures would be published if that happened during an mpg test. Probably a lot nearer the truth?

[Kiwibacon]

One of you lads should request the BSFC (brake specific fuel consumption) chart for this engine. These charts show the fuel consumption (how many grams of fuel for each kw of shaft power) across the full operating range of rpm and load. With such a chart you can nail down exactly what rpm is best to be running in at different loads.

[Guest]

puny, I can tell you exactly what would happen. Those figures would be ignored, simply because the car would be undergoing 'in service maintenance' (just how it is described) and the figures are not representative of the norm. How do I know this, I was an included guest at some official mpg testing a couple of months ago at one of 'Urops' biggest car plants. The car being used started regening during a test. Normally this shouldn't happen as the car being used undergoes a normal drive before hand but this one had been idling too long for long periods and someone had forgotten to take it for a normal run to be sure it was clear in the dpf dept. To be clear, the cars are normal just off the line models, no special preps, no nitrogen in the tyres or anything like that. Just a plain off the production line car chosen at random. It goes through all the normal setup stuff and testing then is driven to put some miles on the clock (all observed by inspectors), then onto the tests. Incidentally, you hear of manufactures putting nitrogen in the tyres for these tests. Indeed, most do that when doing there own tests to see how there cars are performing under mpg test conditions. It just saves hassle with fluctuating tyre pressures. But the actual test itself that I observed was not conducted with nitrogen in the tyres, I specifically asked this question. Many of the critiscms of the tests are based upon myths from what I could see. The tests take into account virtually everything you can think of and I've got to say seemed very realistic.

[percymon]

Many of the critiscms of the tests are based upon myths from what I could see. The tests take into account virtually everything you can think of and I've got to say seemed very realistic.

except of course they are in a lab on a rolling road so no wind resitance, and the surface friction of the rolelrs will be different to a road surface.

I a;so wonder what they do for tyre pressures - Vauxhall handbooks actually give two different tyre inflation pressures (one standard, and the other , higher, for improved fuel economy). I can't remeber the specifics, but i was quite alarmed by how much higher the 'economy' pressures were, at a level that I'd consider to be nothign more than asking for accelerated wear int he centre of the tyre width, plus an uncomfortable ride and increased risk of damage from potholes etc.

Edited 11 July, 2012 by percymon

[Guest]

percymon, the tests take into account everything, including wind resistance and differing road surfaces. It's all calculated with great ease. Tyre pressures are standard. This is why so many, in fact, the majority manage to equal or exceed the EU figures. They actually are quite realistic.

[percymon]

At the end of the day, it doesn't matter how they do the tests, provided they do the same thing for every car - they should be considered as a comparison between one car and another, and not indicative of real world numbers.

[PDIBK]

I have a CR TDI 105 Monte Carlo.

I let my wife run it in (she had to commute 50 miles each way) and she phoned me one day (3 days from new) to say it was "juddering" in town.

I now have 2500 miles on't clock, I haven't headed any particular running in regime, equally I don't drive like a complete lunatic. My daily commute is 40 miles each way, but it is RUBBISH, with no rhyme or reason to whether you'll be stuck behind ANOTHER HGV doing 40mph for 30 miles or no traffic.

Computer says 52mpg most days, brim to brim calculations agree. I'm happy, although it would be good to get close to the 65+mpg and 666 miles per tank, although this smacks of marketing for the Monte Carlo - Devil within and all that!

On steadier runs (really watching the economy and adapting driving style) I have seen the magic 60 mpg. I think it can be VERY dangerous to constantly **** watch though - conditions are different on every journey and trying to ease off or whatever just to get to the holy grail can make your economy worse.

Dad px'd his 1.9 TDI Fabia for a 1.2 TSI DSG, partly swayed by the combined economy figure of 58mpg or whatever and NEVER reaches it - it drove him insane, until I pointed out that the DSG economy figures are IMPOSSIBLE to reproduce and he should just drive it. He took it to the dealer once and they checked it and did the re-flash for an update - no change.

It can be frustrating for sure, but I am switching from a Superb Greenline 1.9 PD 105 (always 50+mpg, any run) and Peugeot 106 1.1i (always 40+mpg, mostly short runs), to the Monte Carlo. I am happy, but there and then, I would only be unhappy if I was getting say 45mpg and for no reason - a bit like the OP. perhaps there was a problem. I'm at work, so trwawling through 18 pages is difficult (I did the first 6 and last 2!!), but I assume he still has the car and it has improved? (Please....!)

[Kiwibacon]

On page 5 of this researc paper there is a BSFC chart of a 1.6tdi engine: http://researchonline.ballarat.edu.au:8080/vital/access/services/Download/vital:3779/SOURCE1?view=true

Can someone compare the top line of that graph to the torque curve on the VAG 1.6tdi?

[lemonvrs]

I have a CR TDI 105 Monte Carlo.

I let my wife run it in (she had to commute 50 miles each way) and she phoned me one day (3 days from new) to say it was "juddering" in town.

I now have 2500 miles on't clock, I haven't headed any particular running in regime, equally I don't drive like a complete lunatic. My daily commute is 40 miles each way, but it is RUBBISH, with no rhyme or reason to whether you'll be stuck behind ANOTHER HGV doing 40mph for 30 miles or no traffic.

Computer says 52mpg most days, brim to brim calculations agree. I'm happy, although it would be good to get close to the 65+mpg and 666 miles per tank, although this smacks of marketing for the Monte Carlo - Devil within and all that!

On steadier runs (really watching the economy and adapting driving style) I have seen the magic 60 mpg. I think it can be VERY dangerous to constantly **** watch though - conditions are different on every journey and trying to ease off or whatever just to get to the holy grail can make your economy worse.

Dad px'd his 1.9 TDI Fabia for a 1.2 TSI DSG, partly swayed by the combined economy figure of 58mpg or whatever and NEVER reaches it - it drove him insane, until I pointed out that the DSG economy figures are IMPOSSIBLE to reproduce and he should just drive it. He took it to the dealer once and they checked it and did the re-flash for an update - no change.

It can be frustrating for sure, but I am switching from a Superb Greenline 1.9 PD 105 (always 50+mpg, any run) and Peugeot 106 1.1i (always 40+mpg, mostly short runs), to the Monte Carlo. I am happy, but there and then, I would only be unhappy if I was getting say 45mpg and for no reason - a bit like the OP. perhaps there was a problem. I'm at work, so trwawling through 18 pages is difficult (I did the first 6 and last 2!!), but I assume he still has the car and it has improved? (Please....!)

I agree