pujro

I know it's early days but I was just trying to establish what mpg the new engines are capable of. We have the 80bhp 1.4 TDI. So far, 4000 miles, averaging about 52mpg on a 60/40 motorway/urban mix. I guess it's ok but our previous 1.9 SDI did 58mpg on exactly the same mix, so I suppose I was expecting better.
Anyone else got any figures on this.
Cheers.

Black

Getting just over 50mpg from my 1000 mile 1.4 TDI 80 bhp which is OK but my 150 bhp GT TDI Golf used to do 47 on the same sort of driving!

I remember with the Golf the MPG improved significantly in the first 10k miles so I am hoping for the same from the Fabia.

anonymouse

It will still be as tight as the proverbial ....

+ also you may be driving it differently to 'the optimum' i.e. wrong gear at times, different speed (cars can often give better mpg at higher speeds depending on the torque and the gearing).
Some examples here -
http://www.briskoda.net/forums/octav...80-85-a/89015/

7k into our vRS and still 'learning' how to drive it....

__________________
"Stupidity, if left untreated, is self-correcting." - Heinlein

FlukemanStu

I've got a new Fabia 3 1.9TDI.

On my first tank i got 51.7 mpg

That included about 70% motorway.

STU

woodenspatulas

im getting about the same but i only drive about 4 miles to work and back, with a bit of motorway thrown in too. but mine has only done 200 miles so far, so im expecting more over the next 3000 or so miles as it loosens up

MissPiggy

last time i looked mine was averging about 44mph. i ahve a 1.2 12v and done jsut over 1000 miles but most of the time its driven in a 30mph limit for 1 mile to get to b/f's house!!!

pujro

Many thanks for the input everyone.
The two versions are quite different, so it may be a driving style thing. Equally different engines bed in at different rates, and it is early days, so hopefully the best is yet to come! It is a much better drive than our old model.
I've put out several queries on this, so will post back if any useful info materialises.

flabio

It sounds right , i had a 1.4tdi-75 for over a year , over11,000 miles the average fuel consumption was 51.7mpg. i was expecting more to , it varied from 44 mpg,and once it did 59 mpg .

pruddell

I've just got 750 miles on the clock on a new Fabia 3 1.4 TDI. I'm VERY disappointed with the mpg so far. I've just done a round trip of just over 200 miles and got an average of 49 mpg. In my Fabia VRS which I also had from new I got around 65 mpg on the same run if I didn't clog it. I wonder if there's something wrong as I always had excellent mpg from all my cars. I drive in a very economical style, gentle acceleration and braking, no excess weight in the car...... I bought this specifically for the fuel economy and am most unhappy. I'll be off to speak to the dealer on Monday to see what he's got to say.

rich17865

low 50's seems about average, and disappointing

Hearny

Let us know, what the dealer has to say.

sharkrider

I just think you need to give it time to run in... 750 miles is not alot... my fiat GPS didn't loosen up and give decent mpg until it had about 2,500 miles on the clock.... it was quite poor until about 1,000 miles had passed by, now, doing a "gentle" fuel economy run like you're talking about, I can get it into the 60's....... before 1000 miles it was more like 45, 1-2000 improved to about 50 2,500 up proper fuel economy

my vRS was the same....

A friend of mine borrowed a fabia 2 1.4 deisel for a few days while his car was having a new gearbox, and he was using it for driving lessons, and was averaging 50 + (and that is mostly slow, and town type driving...) so I'm sure yours will improve with miles.......

__________________
Fiat Grande Punto Sporting (158 bhp 314 lbs/ft) in Red....

Furby vRS , black magic,passenger airbag de-activation switch, (now gone, but not forgotten!)

pruddell

Thanks for your comments. My Octavia and Fabia VRS were much more economical right from new. I'm not happy about it at all. I imagine most 1.4 TDI Fabia owners bought the car on the strength of the mileage figures.
Something is seriously amiss, or someone is doing some serious misleading...

Hearny

Mine is just shy of 5k miles and my milage is going up by the month. Averaging 53.6 from today. Will keep forum posted as to any further increases.

rich17865

The fuel computer on the new fabia takes into consideration idling time in the overall fuel consumption figure. If you sit there and idle you can watch the figures going down.

I have never driven the old fabia, does this one take it into account also?

Plus if you reset the fuel computer when the car has fully warmed up the fuel consumption figures are much closer to the manufacturers quoted fuel figures.

The 1.4tdi engine seems to use an obscene amount of fuel to get itself going.

any thoughts?

Hearny

I have attached a photo of the Milage I was getting today. I covered about 12 Miles and never went over 50mph (around town). I dont know how accurate this on board computers are and I suppose peoples driving style's differ. Any Idea's?

Attached Images

DSC00148.JPG (443.7 KB, 63 views)

FlukemanStu

I have a Fabia 3 1.9Tdi.

I do 86 miles a day, mostly motorway (~80 miles). Last week my tank average was 62.5 mpg. During that week a return trip (43 miles) averaged 72 mpg.

STU

rich17865

It would seem the 1.9 tdi is much more efficient than the 1.4 tdi, sadly.

Like the rest of the 1.4tdi owners i bought mine on the strength of the fuel comsumption figures and road tax price. I know that they are always higher than realistically achieveable, but i would not expect that much higher.

I doubt a complaint to Skoda would achieve anything.

monkey023

The reason behind the 1.9TDI being more efficient is quite simple really. You do not need to work the engine as hard because it has more power and is a 4 cyllinder unit. So it is much more relaxed when cruising at 50-80mph so the engine is not strained as much. With the 1.4tdi you need to work it hard/even thrash it to keep up with faster moving traffic so fuel enconomy falls well below the factory quoted figures.

I have a 1.9tdi fabia mkII and today achieved a 61mpg ride through new forrest + motorways.
I live on the Isle of Wight and even there it is possible to achieve 55-58mpg average!!
The only real benefit on the 1.4tdi is initial purchase cost and lower tax costs plus free parking in some areas due to its low tax band.
I for one need that extra grunt the 1.9 has to offer!!!

Just my thoughts!!

Mark

nickcoll

I'm not sure I buy the theory of a bigger engine using less fuel because you don't have to work it as hard. One factor to consider is that at any specific engine speed a bigger engine will, all other things being equal, need more fuel just to keep it running. This is in part because it has a bigger swept volume to keep fuelled and there are more friction losses from bigger components.

There may be other factors, though, such as the gearing through the drivetrain leading to a bigger engine running at lower revs at any particular road speed, better thermal efficiency of a heavier (more mass) block and so on. I would also love to see some figures for specific fuel consumption for the range of engines.

Of course the other factor is the weight of the overall vehicle, as it obviously takes more energy to accelerate a heavier vehicle. And a bigger engine is heavier than a smaller one. Once running on a level road, though, the energy required to keep the vehicle moving is more affected by aerodynamics than it is by vehicle weight, and this is even more the case the faster the vehicle is travelling.

One interesting observation I have made recently is that the official fuel consumption figures for a Fabia with the 1.9tdi engine (44.1/68.9/57.6) are almost the same as an Octavia with that engine (44.8/67.3/57.6), even though the Fabia is only three quarters of the weight of the Octavia (1170kg/1500kg). So where is the benefit in buying a lighter car in efficiency terms? The only benefit that is left is a smaller price, but it appears that anyone who is buying a lighter car for the fuel efficiency benefits is kidding themselves.

The other factor may be that the Fabia will obviously accelerate faster with the same engine, and it is possible that if you kept the performance of the Fabia down to that of the Octavia you would get a fuel efficiency gain, but I would have thought that the official fuel consumption figures wouldn't reflect performance differences anyway. Certainly the steady-speed figures shouldn't have any aspect of performance built in to them.

The final variable is aerodynamic efficiency, and I must say that I do wonder whether the Fabia is maybe vastly less aerodynamic than the Octavia, and that is what causes the figures for the Fabia to be so bad? It's the only other variable I can think of, but I would love to hear from others with their speculation on this interesting topic.

Personally I am looking to get a new car and I am looking for a very fuel-efficient vehicle that is as capacious as possible. In many respects the Fabia 1.4TDi 80 Estate satisfies my requirements, but every time I have test-driven one I have been very disappointed with its economy. This is based partly on having an Octavia Scout 2.0TDi which gives 45mpg overall, with 55mpg achievable fairly easily on a run. The Fabia just doesn't seem to give any better figures when I drive it in the same restrained way on the same roads, and this is putting me off.

I have been wondering whether the 1.9 might be better, but as mentioned at the top of this post it seems to me that it shouldn't be any better. There must be more overheads with a bigger engine, mustn't there?

mcalp

Should not power to weight ratio come into the equation somewhere?

d96em

Not necessarily.. different engines have different power bands. Smaller engines often have power bands that hit maximum torque at a rather high rpm, meaning that the driver will be using the engine in a suboptimal manner when he cruises at low rpms. A larger engine with a lower power band may use less fuel because it will be using it more efficiently.
This is what a CVT (continuously variable transmission) is good for; it will keep the engine running at its peak efficiency rpm throughout acceleration, effectively saving fuel. If your car has a small engine with a high power band that means it won't make full use of the fuel when cruising at low rpms. Try comparing the power bands of the 1.4 and 1.9 engines (and the transmission ratios if they differ), perhaps they'll give a hint as to whether the larger engine is more fuel efficient.

You wrote that at any given engine speed, a larger engine will use more fuel than a smaller one. But it's not quite that simple; as I've mentioned, if that particular engine speed happens to be in a suboptimal band in the small engine but near the peak efficiency rpm in the large one, the smaller will likely use more fuel than the larger. Just because the displacement is bigger you can't conclude that more gas will be going through in the same amount of time. The fuel injection system will constantly monitor exhausts, current rpm, flywheel speed and a plethora of other parameters and then decide just how much fuel to inject. Modern engines actually use no fuel at all when it's not necessary (like when going downhill and letting gravity do the job). Also, friction losses are likely larger in a smaller engine due to the fact that it will likely be run at higher rpms, and bearing friction is directly proportional to rotational speed.

Philip26

One point nobody has mentioned is the temperature...

for example I travelled the 125miles to my parents - Trip computer read 70mpg Av. Temp. 14oC - Return Trip computer read 59.5mpg Av. Temp. 2oC (My trip computer exaggerates a little!)

I find any temp. below 10oC economy drops off then below 5oC it drops off a lot!

I've averaged about 52mpg (rim to rim) myself over this cold period but I will expect to see 60mpg+ when the temperatures pass 10oC average.

I don't think any of your figures are bad! Just let the engines bed in and wait for warmer weather

__________________
Philip

Nurburgring Tourist 2006
Oulton Park Trackdays: 03/11/06, 26/06/07, 02/11/07
VRS now Jabba'd - Stutter & (Nearly) Smoke free

nickcoll

@d96em:

Yes, I referred to some of those factors in my post. Part of the problem is that these questions are not answered by any of the information I have access to. For example, what is the torque/bhp profile of the engines, and what is the gearing through the drivetrain? This sort of information used to be provided in many car brochures, but it certainly isn't in the Skoda ones.

On another point - I have found that coasting downhill has a dramatic effect on mpg, so although I am sure modern engines do substantially reduce fuel supply on the overrun, it doesn't look to me like they reduce it as much as running the engine at idle. I think it's correct to say that if you were to totally cut the fuel off the engine would stop, so there must be a minimum requirement for fuel going through the engine. And it seems reasonable that the minimum amount at 2,500rpm is going to be more than the minimum amount at under 1,000rpm. That is certainly the indication of my experiments with this.

One further point - I know that the official fuel consumption figures are necessarily limited in their value as all such tests will be, but they should give SOME indication of relative efficiency of the engines in a relatively objective way. This does assume, of course, that the manufacturers carry them out and report the figures honestly, though. If the 1.9 is more economical in actual use than the 1.4/80 does this maybe mean that this is not the case?

d96em

No, the engine doesn't stop, it just doesn't keep turning by force of combustion but rather because it is directly connected to the wheels. If you were to put the transmission in neutral while coasting, the ECU would have the fuel injectors pulse enough fuel to keep the engine from stopping dead (i.e. having it run on idle rpm), but as long as you keep it in gear there is nothing that stops it from completely cutting fuel. When you reach the end of the slope, engine rpm will drop to a level where the ECU will start injecting fuel again to keep the engine from stalling.

I'm not sure what those figures are, but they should all be based on the same drive cycle, and that cycle likely fits some engines better than others. I'm not convinced you could directly link their relative figures to real life mpg figures, unless of course in real life you drive exactly like the test cycle.. it's a good point though, and if not the entire truth probably at least points in its general direction