Fabia 1.6 CR TDI 90bhp appalling fuel consumption

[greenline 11]

Wwwwww decisions decisions ? Give skoda a chance too rectify if they don't you can still go for the rio, however the matter of the deposit like you say 14 day cooling off is applicable so just cancel it

Hi,

Estateman seems it could be a malfunctioning injector. I will give it one more try as my local daeler has asked for the car for a few days indicating to me they are going to give it an indepth. As EM suggests a half decent tech might fault find it easy but time inhibits them so they tend to look for codes instead. Let's see what happens. I'll post which ever way it goes. Be nice if it was fixed, it's an otherwise nice car!

[seboni121]

Greenline as long as they've got a good tech at your dealers its ok?, my dealer here fooked me about and I ended up selling both my fabias , nothing wrong with my fabias just cut of my nose to spite my face!, big mistake and I bought the mk6 golf and I don't regret it, however I will be buying another skoda but not a fabia , all the best and don't settle for anything other than perfection

[Brimma]

Just another thought on my prior post. I guess it's possible the smell was from accumulated debris being burnt within the engine and pathways out. Driving it 'like an old woman' to get the best mpg is OK to a point, but we all know deposits can build up in the engine, especially places like the EGR value etc. Is it possible the smell was from these being burnt off or blown out in some way? I did notice when I first got it and for some considerable time afterwards that during a regen it would smell quite a lot, which was a bit rubbery. However, this latest smell was much more intense and from memory, much more of rubber rather than a general hot smell. It has been a while though.

Mike, you're not the only one getting occasional strong burning rubber smells

I've had the same, but it's only intermittent, not every trip, and you can bet your life that if you take it to the dealer it won't do it

Recently I've taken to driving for much longer periods in 4th gear, and found that it has hardly any effect on fuel economy, in fact on some occasions it's actually improved it, restricted to single carriageway roads obviously, not 55-60mph +

[PDIBK]

I get the stink once a week - so possibly it is a regen issue.

Sometimes it seems as if the stink is there to remind me not to wring it's neck so much.

As the smell didn't seem to be linked to a particular timeframe, I half ruled-out the regen thing and began to wonder if saomething was trapped somewhere.

I supsect now, after this latest flurry of burning rubber stories, that my regen causes it and my 10 mile each way trip means it is happening as I get home...so, I will drive faster and further occasionally!

[seboni121]

Well when I had the fabia 1.6 crtdi 105bhp I did get the eggy plastic burning smell every so often, however I've now got the golf with the same engine and never seem too get the smell ?, I must say though I do drive it quickly on an occasion and only use the vpower diesel

[Igloo Vindaloo]

I smelled something for the first time after driving up a mountain near Geneva in 2nd gear. I don't usually exceed 3000rpm for more than a few seconds. Probably should do more often...

[Igloo Vindaloo]

Recently I've taken to driving for much longer periods in 4th gear, and found that it has hardly any effect on fuel economy, in fact on some occasions it's actually improved it, restricted to single carriageway roads obviously, not 55-60mph +

Enough of this nonsense! Higher revs burn more fuel! At least on cruise.

Proof by experiment:

90km/h (indicated, actually 86km/h by GPS) driven on cruise control on a dead straight, dead flat autobahn for 5km in 5th gear, then 5km in 4th gear.

5th gear - 1750rpm - 3.2km/h average (88MPG)

4th gear - 2300rpm - 3.7km/h average (76MPG)

(+1.5C, constant 10km/h headwind, 1 passenger, winter tyres, dipped headlamps, radio, heater on auto at 20C, engine already warm - after 5km driving)

[seboni121]

Vindaloo I agree with your experiment , however brimma wasn't travelling on a flat autobahn at night, when this engine is on a standard B road with loads of bends and travelling under 50-55 the car labours and turbo isn't spooling , this engine will defo use more fuel so better leaving in 4 th even though the gear selector tells you to shift to 5 th

[jaxx007]

I get the stink once a week

The wife hasn't let me do that for years lol

[Guest]

Enough of this nonsense! Higher revs burn more fuel! At least on cruise.

Proof by experiment:

90km/h (indicated, actually 86km/h by GPS) driven on cruise control on a dead straight, dead flat autobahn for 5km in 5th gear, then 5km in 4th gear.

5th gear - 1750rpm - 3.2km/h average (88MPG)

4th gear - 2300rpm - 3.7km/h average (76MPG)

(+1.5C, constant 10km/h headwind, 1 passenger, winter tyres, dipped headlamps, radio, heater on auto at 20C, engine already warm - after 5km driving)

Yes...the test you did is what I would expect on your car under those condition. But it also depends on the speed, load and other conditions being encountered and not just the engine revs as Seb is saying. No one has suggested driving as you did in 4th gear all the time on a motorway or dual carriageway. That's plain silly! If your speed is high enough then 5th gear is the obvious choice for those conditions. But for best efficiency in the CR 1.6 (the engine the thread is about) it seems to run best (most efficiently) at 60mph plus in 5th and not below that (according to what owners are overwhelmingly saying and what the dyno testing revealed in my survey tests). It tends to use more fuel on country roads for example if in 5th gear at lower speeds. However, under those conditions 4th gear can often add and improve considerably the mpg figures when driven in that gear below 50-55mph depending on those other factors such as load, topography etc etc. 5th gear is quite a high gear ratio. In my survey, I found many new or newer owners of these 'new breed' diesel engines 'slog' the engine around like an older diesels in too higher gear (without realising they are doing that) which gives poor fuel economy, as the engine is in effect being driven uphill all the time in too higher gear with too few revs. That is overwhelmingly what my survey found when looking into this poor mpg thing on this engine. It's also the fact that the 1.6CR engine is a shorter stroke engine than previous diesel engines, and that means it's loves to rev! Forcing it to go at too lower revs will use expotentially more fuel under most circumstances than an older longer stroke diesel. Just what I found when doing my poking around!

[Igloo Vindaloo]

I would like to try the same experiment at 80km/h (50mph) and 70km/h, but the only constant speed I can drive at is 90km/h (except in the middle of the night) - because that's what the trucks are limited to here.

To test your theory, Estate Man, would require a much more difficult experiment, ramping up and down speeds in a fixed pattern, but shifting gears at different revs.

Hang on - that's exactly what the EU standard fuel efficiency test does! http://en.wikipedia.org/wiki/New_European_Driving_Cycle

In fact, the ECE R101 Extra-Urban cycle includes acceleration from 70-120 km/h (43-75mph) all in 5th gear - exactly what you are advising us not to do. This is surely the most fuel intensive part of the cycle, yet it is this test that yields the hopelessly optimistic 3.0L/100km (94MPG), which I have only achieved on a long run at a constant 90km/h (at 25C) - and that's not accounting for the fuel computer being 5% over-optimistic.

[greenline 11]

I would like to try the same experiment at 80km/h (50mph) and 70km/h, but the only constant speed I can drive at is 90km/h (except in the middle of the night) - because that's what the trucks are limited to here.

To test your theory, Estate Man, would require a much more difficult experiment, ramping up and down speeds in a fixed pattern, but shifting gears at different revs.

Hang on - that's exactly what the EU standard fuel efficiency test does! http://en.wikipedia....n_Driving_Cycle

In fact, the ECE R101 Extra-Urban cycle includes acceleration from 70-120 km/h (43-75mph) all in 5th gear - exactly what you are advising us not to do. This is surely the most fuel intensive part of the cycle, yet it is this test that yields the hopelessly optimistic 3.0L/100km (94MPG), which I have only achieved on a long run at a constant 90km/h (at 25C) - and that's not accounting for the fuel computer being 5% over-optimistic.

...............................

I have to say Igloo and without any meaningful malice to other posters on this subject, my own findings more or less correlate with yours. Far better mpg in 5th gear than 4th gear at the speeds you describe.

What is also very pertinent is that the test is very, softly, softly. There are constant instances in the Wiki account 'gently accelerate' which sort of throws a spanner in the works of the notion we should be permanently accelerating the arse out of these cars! I made a mention last week of a long journey I did on fast A roads and motorway and keeping within speed limits and taking the advice of keeping my revs up whatever gear I was using at the time I achieved 50 mpg rather than the usual 55 mpg which I think is very poor return anyway!

But where does that leave us all now. Surely the whole idea of the figures published by manufacturers is to help us all make wise and informed decisions in what car we should buy. If Skoda publish a figure of 83.1 mpg for combined and then my car for example then gives a return of 50 mpg why the hell do we need to know about figures when so far out of sync' with reality! For my car there is a shortfall of 45.7% !!! Now if the figures were say 5% out or 10% if one drives like a bloody maniac one could put it down to the driver, but 45% short of target for **** sake is manifestly taking the ****!

Skoda will have my car for a couple of days now as they are conducting an in depth test in liaison with VAG to see what is causing the engine to 'hunt'. If a fault is found and remedied and then I discover I get far better mpg then I will keep the car, I should have the car back in a few days then that gives me a fortnight to check mpg's before deciding on my option to trade it in March 6th.

[Guest]

To be frank Igloo, you don't need to test my theory, just your own driving technique for your sort of roads and conditions. It's not my theory, it's actual engineering fact for any engine that if it revs too low it can be inefficient. All engines has there sweet spot/s whether it's petrol or diesel where they run best and most economically. The question is 'what is too low revs'? Where is the sweet spot? When I put the 1.6cr on the dyno it always showed it was using more fuel at 50mph in 5th gear than at 55 or 60mph in the same gear. That is what I expected since it is a short stroke engine with low piston speed. That means it can sound as if it's revving ok but actually it is not necessarily running at it's most efficient. That is reflected in what many others are saying here in this thread, but not always. It just depends on all those other variables when you are in actual real driving conditions. Overall it does apply though as most are finding out. Don't confuse this mpg issue with one or two who may have an actual engine fault, that's entirely different and they may get different results until the engine is fixed. It's easy to forget that just because someone on here is not getting their perceived mpg's they expected from their cars, that not everyone is in the same boat. Most do achieve near or actually get the EU figures. the last Greenline 11 I took to Wales achieved 72mpg with a heavy GSXR1000 engine in the back and a passenger. That's what I'd expect under those conditions on a long run. Without the engine and passenger I'm sure I'd have achieved 80+mpg easily and I wasn't hanging about 75mph most of the way indicated with bursts of 80mph for long periods. I know about the EU testing, I've been present during some official testing and seen for myself how it's done and why. The results are for yardstick purposes only but do offer some realism. Whatever the test that's used it will never be right for everyone and someone will always complain they cannot achieve it, and that just misses the point of the tests altogether.

Edited 13 February, 2013 by Estate Man

[Brimma]

Obviously you're not going to get better economy at motorway speeds in 4th, that wasn't what I said

What I did say was that on normal single carriageway roads it is possible to get higher readings by remaining in 4th, and not changing up to 5th when the computer tells you

There will be an optimum speed when this is not the case, maybe around 50mph, but it can hold good at speeds below that

[MikeHart]

Mike, you're not the only one getting occasional strong burning rubber smells

I've had the same, but it's only intermittent, not every trip, and you can bet your life that if you take it to the dealer it won't do it

Recently I've taken to driving for much longer periods in 4th gear, and found that it has hardly any effect on fuel economy, in fact on some occasions it's actually improved it, restricted to single carriageway roads obviously, not 55-60mph +

The really strong burning smell was pretty much only for that one trip. I've had a bit of a smell a couple of times since, but nowhere near as strong. I think estatemans suggestion that its deposits burning off is probably correct. However, it does suggest there's a lot of deposits being left behind and the engine is burning far from clean. I'm going to put a cleaner through it tomorrow.

[MikeHart]

Enough of this nonsense! Higher revs burn more fuel! At least on cruise.

Proof by experiment:

90km/h (indicated, actually 86km/h by GPS) driven on cruise control on a dead straight, dead flat autobahn for 5km in 5th gear, then 5km in 4th gear.

5th gear - 1750rpm - 3.2km/h average (88MPG)

4th gear - 2300rpm - 3.7km/h average (76MPG)

(+1.5C, constant 10km/h headwind, 1 passenger, winter tyres, dipped headlamps, radio, heater on auto at 20C, engine already warm - after 5km driving)

I think the answer is a bit of both. If you're accelerating, not straining the engine, being at low revs will save fuel, but if cruising at a steady speed (and comfortable for the engine), a high gear will use less fuel. If you're on a flat, high speed road, staying in the highest sensible gear should give the best results. If you're on windy country roads, the constant up and down in speed means a lower gear will do better.

[MikeHart]

...............................

I have to say Igloo and without any meaningful malice to other posters on this subject, my own findings more or less correlate with yours. Far better mpg in 5th gear than 4th gear at the speeds you describe.

What is also very pertinent is that the test is very, softly, softly. There are constant instances in the Wiki account 'gently accelerate' which sort of throws a spanner in the works of the notion we should be permanently accelerating the arse out of these cars! I made a mention last week of a long journey I did on fast A roads and motorway and keeping within speed limits and taking the advice of keeping my revs up whatever gear I was using at the time I achieved 50 mpg rather than the usual 55 mpg which I think is very poor return anyway!

But where does that leave us all now. Surely the whole idea of the figures published by manufacturers is to help us all make wise and informed decisions in what car we should buy. If Skoda publish a figure of 83.1 mpg for combined and then my car for example then gives a return of 50 mpg why the hell do we need to know about figures when so far out of sync' with reality! For my car there is a shortfall of 45.7% !!! Now if the figures were say 5% out or 10% if one drives like a bloody maniac one could put it down to the driver, but 45% short of target for **** sake is manifestly taking the ****!

Skoda will have my car for a couple of days now as they are conducting an in depth test in liaison with VAG to see what is causing the engine to 'hunt'. If a fault is found and remedied and then I discover I get far better mpg then I will keep the car, I should have the car back in a few days then that gives me a fortnight to check mpg's before deciding on my option to trade it in March 6th.

Hello Greenline,

Your experience seems to correlate with mine, but I don't have the hunting, or at least, not that I've noticed. I've certainly noticed that on country roads, it's best to stay in the highest possible gear when slowing or staying steady (even 5th at 40mph) and only change down when accelerating. May be strange and applicable to my car, but I already believe I've got some sort of problem that Skoda are incapable/can't be bothered of fixing.

[MikeHart]

Well, to add more fuel to the fire!!

My last tank of fuel on my previous driving style returned around 63mpg, brim to brim.

That means driving like a granny, cruising at 50-55mph and keeping in the highest gear possible and the revs real low. Like 1000-1500 for the vast majority of the time. Also, accelerating from say 40-50mph in 5th.

My first tank of fuel on my new driving style returned around 53mpg, brim to brim.

That means keeping the revs high, 4th till about 50-60mph. Majority of the time with revs between 1500-200, although higher when accelerating. Accelerating from 40 to 60-65 for instance in 4th gear. Cruising speed, 60-70mph, averaging about 65mph.

Now, according to the majority of people, this is all wrong. However, it does seem to correlate in some ways with Greenlines findings. Personally, the obvious difference is the use of the turbo. In the modified style, the turbo is used far more than in my previous style.

To ensure it's not something about the ECU retuning to the new style and to allow for the removal of deposits etc., I'm going to run another tank through using the new style.

Out of interest, I have a couple of questions that estateman or someone else might be able to answer.

1. What's the best fuel system cleaner for use with a DPF? Want to run one through and get rid of as many deposits as possible.

2. Does anyone know of a decent cheap interface and software between the cars 'bus' and a PC (laptop). I'd like to get some graphs of the various parameters whilst driving, especially the engine load one. Plenty on eBay, but I know some work better than others.

[Kiwibacon]

How about a combination of the two?

Accelerate using the turbo but drive using the lowest revs at very low engine load (like flat cruising at 35mph).

[MikeHart]

How about a combination of the two?

Accelerate using the turbo but drive using the lowest revs at very low engine load (like flat cruising at 35mph).

Hello,

I have done this in the past, and it didn't make a lot of difference. The really critical factor in my journey appears to be the dual-carriageway cruising, more specifically, the speed. However, as this correlates to a RPM and therefore to whether the turbo is operating or not........hence my idea its the turbo causing issues.

After the current test, I might well retry this and see what happens. I think it should be better than my current 'keep the revs up' mode, but not as good as my 'normal' driving. I'll give it a go and see.

[jonny boy]

[Brimma]

If you're that bored don't read it

Simples

[Igloo Vindaloo]

The really critical factor in my journey appears to be the dual-carriageway cruising, more specifically, the speed.

Speed Kills!

It's simple physics KE=(1/2)*mv^2 - It takes twice as much energy to get to 70mph than 50mph. And the frictional losses increase ~linearly too.

In the car's handbook there is a nice graph showing the fuel consumption as a function of speed.

But it's easy to make your own, giving a long flat road with little traffic, steady wind and temperature and nothing better to do for a few hours.

Here's one I made in the summer

(25C, light wind, only me in the car, each calculated over a 20km run with no more than 20m change in altitude, speed from GPS, not car):

km/h l/100km Mph MPG

90 3.0 56 94

100 3.2 62 88

110 3.4 68 83

120 4.2 75 67

I would love to see the same experiment done with the Seat Ibiza ST with the same engine, as I suspect it would do better at high speed due to better aerodynamics.

Edited 15 February, 2013 by Igloo Vindaloo

[io1901]

Just as an aside:- I have the Octavia Greenline II estate which has the same engine and is currently averaging 66mpg. I have noticed that on my daily commute the car makes the best mpg in the last third of the journey. First third the OBC reports under 50mpg, by the 2/3s mark it's about 60mpg and by the end (depending on traffic) is between 64-70mpg. This is a journey of about 40ish motorway miles. This suggests to me even if driven at a constant reasonable speed the Greenlines aren't going to get any where near it's reported mpg if driven for distances under 20 miles.

If I don't use the motorway and use the A roads it struggles to get over the 60mpg mark.

I find the gearing suits motorway cruising at 55-65mph in 5 gear.

[RandomSkodaperson]

Interesting thread!

I have the 105 CR in my Roomster and it always seems to regen every 100 miles or so. The burning egg smell is horrible. The car is coming up to three years old and has been great apart form the regen smell. Should I get this looked at before the end of the warranty or is it norm for this car?

The regen happens even if I have just been on a really long motorway drive. For example, drove about 120 miles at about 65mph and it was going the regen when I got home. I would have thought it would have been ok on that run to burn things out.

I have just been to Kent and back about 500 miles in one day and the Roomster was fantastic. It was showing 62 mpg at a steady 65-70 and the fuel guage was showing more towards the half tank left rather than quarter! Amazing little engine.

Tempted to keep it or perhaps look at the greenline options depending on the part ex deals.

Just read io1901 above and agree that 5th at around 65 the car is perfect and runs all day.

Edited 15 February, 2013 by RandomSkodaperson