Recently changed my wife's trusty Fabia I to a newer, 2009 Fabia II.  Same engine, 1.2, 60BHP. The trouble is that the new car is getting ridiculously low mpgs - the last time we've checked it, it has done roughly 270 miles and used 41 litres of petrol.  Similar results over last 4-5 fills.

I have read somewhere about cleaning the MAP sensor, so done that, but it didn't change the consumption a bit ... I know it's winter, the car is on winter tyres, and my wife only does 1-2 mile trips to school/shops, but the previous Fabia was doing much better (42-45 mpg) in the same conditions...

 

Any tips or advice what I should be checking ? My idea was to replace the MAP sensor alltogether, but if this won't help ...  Called Skoda dealer only to hear that our 1 year warranty "might not cover it" (despite saying during the sale how great this warranty is compared to other brands)  as they never heard about such a problem with these cars (?). They say I would need to book the car for check-up, which will cost roughly £80 and does not even guarantee that they will find the cause of this.... I am very disappointed... 

My htp 70hp usually gets around 45mpg depending on how and where its driven.

What exactly are you getting at the moment in mpg? I know i could work it out from what youve said haha.

Also, what year is the car? How many miles?

2009 , 59 reg, just hair under 20k on the clock.   Getting between 28-32 max over last 6-7 fills

Is that over a decent size run? You should defo be getting alot better than that.

Ill be interested to hear other peoples inputs on this, as i cant think of a way i can help myself. Especially if you were getting 42-45mpg on your previous engine over similar journeys.

Short journeys like that would probably one allow 30-35 mpg.

 

As well as the Mass Air sensor the cam sensor can go which make it feel and act sick.

 

Could be a different sensor or its lead to the EMU or a plug not working fully.

rbss, you wont get better mpg figures if the car is only being used for journeys of 1-2 miles at a time. The engine and oil are little more than cold for the entire trip. The injection system will be chucking fuel into the engine at a very fast rate. In addition the engine on the newer model has to meet more stringent euro emmision laws which can further hamper the mpg. I doubt you have anything wrong. But you should not compare your new car to your old one. There are differences. Take it for a longer series of runs and recheck your fuel figs, I bet its ok.

How does the euro emissions laws hamper the mpg? Wouldnt it make it better?

I used to drive a 2005 polo with the same 1.2 12v as my 2013 fabia. It had different characteristics but it was about the same on fuel. The fabia is actually better on the motorway due to the drop in engine revs, because of the gear ratio change in 2010

Guys, apologies, I have not told the whole story. Out of roughly 280 miles before refill (my wife never allows the reserve light to come on ) 50-60 is on motorways doing 50-60mph.  This happens pretty much every weekend.  

After we have cleaned the MAF sensor, I have tried to take the car for slightly longer trips (30-40 min drive at the time) with more steady speeds of 50-60mph. So over last 2 runs, I would say half of the miles were the motorway miles.  Initially I thought that the fuel gauge disappears slower, but it looks like cleaning did buger all to the mpg.  I will tank the car over the weekend and update the thread.

I know short trips are not great for getting high mpgs, but previous Fabia was doing exactly the same trips, and was returning much better results...

Might be worth double checking the tyre pressures. Also worth a look at the brakes/handbrake to ensure no binding-on etc.

Also worth checking /replacing the air filter?

Your saying winter on winter tyres, well with the right tyres pressures that should cost nothing extra in fuel. Not if the weather is cold.

& you get 30 mpg average from 9 gallons over 270 miles.

 

But does the engine run when the miles are not clicking up.

Have you had a cold winter.

Car sitting warming up before driving, and sitting running while parked waiting on anyone to keep the heater running.

 

You are getting Winter Spec fuel and have done since November and that should help MPG not reduce it.

 

So a 60 ps car up the motorway, how much weight is it carrying?

1-2 miles in cold weather, and if any engine running longer than driving,

you maybe get 25 mpg then, if you had an accurate computer it might show you are using a gallon every 20 miles on the mileometer,

or if it gets the 30 miles from each gallon that seems good to me.

 

(i have a petrol 68bhp Kia auto and around town for a mile or 2, and out of town it does 40 mpg at its worst.

But then the coolant is hot in 3 minutes even when temps are around freezing.

When it needed a new coil and spark plugs it did 30 mpg.

Basically it was running on 3 cylinders and it is a 4 cylinder engine normally.

A mile or 2 each day in a vRS will use a gallon for 20 miles or even less.when it is cold )

 

PS. for an easy check.

Brim the tank, do not vent it if the car is not going far, just the 1-2 mile trips.

 

So fill the cars tank up full, & fill a 5 litre can, or just put in 4.546 litres, and zero the trip.

Then after the car has done 30 miles, put the fuel in from the can and see if it takes it all.

IMO the high consumption is normal for a htp of that vintage. My '09 70bhp fabia had terrible low 30's consumption for a long time.

 

The htp has very high consumption during the warm up phase, which lasts at least 3 miles. It is also very sensitive to the right foot, a heavy foot sees ridiculously low figures.

 

The car is now starting to creep up to just over 40 mpg after 35,000 miles, but town driving kills that figure. Its the price you pay for the HT in HTP. Yes, it has good High Torque at low speeds, but thats because the engine runs rich ( my opinion) at low revs.

 

If you want to experiment, try changing the Lambda sensor(s) - there are 2 on the 60bhp engine, one pre and the post cat. They ultimately control the fuel air ratio. They are expensive however.

 

There may be a way of trimming the ratio via vcds (full version) - I'm not sure.

 

Try changing up at higher revs 2500rpm, keep away from labouring the engine below 1500 rpm, which is easy to do as its so willing, but thats the area where the consumption is **** poor.

 

Previous 64bhp fabia mk 1 htp we have has much better economy, but is prone to stall at low speed manouvering due to much lower torque at low speeds.

 

Note: the htp engines were heavily revised in 2010, so don't compare your engine to those as the later ones are considerably better on fuel.

Edited 27 February, 201412 yr by xman

Touchy subject, but could it be driving style?

 

If you and your wife were used to the old Fabia, with the same engine and now drive the new one the same way, then the differences in the car (different weight, set up, emissions provisions, tuning etc etc) could be giving the differences.

Very interesting read this is.

Anybody know what exactly they did change in 2010?

I know the engine seems like a completely different one now. Even the engine note is completely different, and it seems somewhat less responsive. Id be interested to know exactly what they did change

Cheers

Not sure it's the 2010 facelift that changed stuff (although that may have introduced more sound rdeadening etc), the OP has changed from a Fabia Mk1 (so pre-2007) to a Mk2.

 

Those are similar, but different cars.  Could be different gearing, different map, different tune to achieve emissions figures and make the unit Euro5 compliant (or whichever legislation)...

Its not more sound deadening, its a completely different engine note. The pre 2010 triples have a whinney whistley sound and the later ones dont have this. Its hard to explain haha.

And to the op, does the car show and signs of running rich? Is it smooth? Free revving? Anybody mention anything about the colour of the plugs when it was last serviced maybe?

Anybody know what exactly they did change in 2010?

I know the engine seems like a completely different one now. Even the engine note is completely different, and it seems somewhat less responsive. Id be interested to know exactly what they did change

 

 

The engines were heavily revised for the 2010 facelift, all moving parts were "optimised" for size and weight, crankshaft, rods, pistons made smaller/lighter, bearings were reduced in size to reduce energy loss. A major change was the duplex roller camchain was ditched for an inverted link chain drive. This has higher efficiency and lower noise.

 

They redesigned the counterweights on the crank, I think that allowed them to remove the gear driven contra-rotating balance shaft. That's where the whine was generated. The CO2 went down from 140g/km to 128 g/km.

Edited 27 February, 201412 yr by xman

Ah thats good to know. Thankyou .

I had under estimated the size of the revision quite drastically then. It was pretty damn big haha.

The cam chain change really explains alot too. On the 2005 polo i used to drive, you could hear the camchain noise quite well, but mine ticks over alot quieter, even from an external point of listening.

Edited 27 February, 201412 yr by Otaylor38

I have finally have a spare sec to update the thread - apologies for the delay.  All good points from the posts above. Cleaned the sensor one more time and checked the consumption on the full tank. This time the mpg went up to 35mpg -saying that, I was driving the car much more, and we probably spent 50-60% of the time sitting on motorways doing 50-60, and runs through the town (not much traffic, so fairly good runs).  I am tempted to replace the MAP with a new one and see what it does to the mpg.

Driving style - both me and my wife drive like grannies - I usually manage to either beat, or match the stated manufacturers consumptions , but I am waaaay off with this car

Cleaned the sensor one more time and checked the consumption on the full tank. This time the mpg went up to 35mpg -saying that, I was driving the car much more, and we probably spent 50-60% of the time sitting on motorways doing 50-60, and runs through the town (not much traffic, so fairly good runs).  I am tempted to replace the MAP with a new one and see what it does to the mpg.

 

What exactly are you cleaning?

 

AFAIK there is no MAP sensor on the 1.2 htp. MAPs and MAFs are restricted to turbocharged engines.

That's the part I was referring to:

http://www.ebay.co.uk/itm/170804820272?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

another reading, nearly 37 mpg. Going up very slowly, but this time it was mainly motorways doing 60-70mph... I would expect much closer to 50mpg figure ...

You say you drive like grannies - that's the bit I was referring to.  In my CR TDI monte, you absolutely cannot drive it like an old school diesel (shifting into 5th at 20 mph).

 

Maybe your newer car doesn't like pootling along in too higher gear.

 

That said, you reckon you're doing more 50-60mph work, so you'd expect that to mean less.

 

Dunno.

another reading, nearly 37 mpg. Going up very slowly, but this time it was mainly motorways doing 60-70mph... I would expect much closer to 50mpg figure ...

 

Our old 2008 htp70 would do 50mpg on a run to the coast (80 miles A and B roads 40-60mph.) On my motoraway trip to work if I kept below 70 mph I'd get mid 40's mpg. Above 75mph then I'd be struggling to get 40mpg.

 

It really drank fuel as you pushed past 75mph.

 

Cheers

Lee

Motorway speed limit was 70 mph anyway as you trundled in your 70bhp car, 

so as it lacked oomph it was using more fuel on inclines,

it will have been getting amazing consumptions on down slopes.

 

& to the Coast is always generally downhill i find,

so must be mostly uphill going home if you live inland.

 

I learned that as a child when i had a pushbike.

 

I drive a 68 bhp petrol auto as my regular driver before i get told i have no conception 

of economy cars and aerodynamics, it does 40 mpg min even at licence loosing speeds.

A 1,100 kg 70hp Fabia MK2 is like a slippery snake

in comparison to my mini heliphlumps frontal area also about 1,100kg.