Hi,

To cut a long story short, my car is terrible on fuel economy. I can get a consistent 40mpg and my daily commute to work is 15 miles on an A-road and a motorway so it's in no way stop-start travelling. I drive it sensibly, rarely have to 'floor' it, but it's just terrible on fuel...

E.g, I put £10 in the other day and it got me 40 miles...£25 in on Saturday and I've done 90 miles and it's almost in the red. I haven't the slightest about what might be causing this so any help would be appreciated. I know for sure I should be getting more out of it than that. Could it be to do with where I fill up? I can only assume there are crap Petrol Stations to fill up in and decent ones. 9/10 I use Tesco, Sainsburys or Shell (all nearby home or work).

It's a 1.4 Fabia Elegance 16V 2000 model.

Help/advice appreciated!

When was it last serviced ?

1st guess would be its in need of a good service - air filter,oil and sparks. does it feel as if its missing at all?

2nd would be a dirty MAF

When I bought it there was no service history so I think it's definitely way overdue. It feels like it should have a little more poke in it though. I'll have it serviced and see how it is after that. Thanks

Tyre pressures are the other obvious thing.

When was it last serviced ?

1st guess would be its in need of a good service - air filter,oil and sparks. does it feel as if its missing at all?

2nd would be a dirty MAF

It doesn't have a MAF, guess again.

I would suggest that a new ECU temperature sensor would be a good start given the cars age.

Any lights on board on? Is the temperature reached fast? Feels sluggish?

Mine's the same. averages 40mpg when I expect more.

So far I've checked the rear brakes and added caliper springs. Cleaned the EGR valve out and refitted. Check tyre pressure weekly. I was also minus 6th gear for a while.

I've definitely noticed a small increase once all the above were done. I was often on the 38mpg side of 40. Where as now I'm looking at more 42mpg.

Oil and filter change is next for me. And if yours is well overdue, I'd certainly get that done first, as that may well be your answer.

Mine's the same...

No it's not, OP has a 1.4 petrol, you have a 1.9 diesel.

OP make sure you run the car on super plus unleaded and not the cheap stuff and change that temperature sensor and the sparkplugs.

No it's not, OP has a 1.4 petrol, you have a 1.9 diesel.

I was referring to situation, not model of car.

In my experience, a simple oil change can make a big difference :-)

I had probs with a previous car which used to average 65 mpg & at one point reached an all time low of 48.

Forum members advised me to change the oil.....hey presto! 65 mpg again lol :-)

Not saying you'll achieve anywhere near that in your fab tho ;-)

In the past week my 1.9 TDI has been drinking fuel, I put this down to using more strain on the car with using the lights,heater,heated seats,heated windows/mirrors . I changed to winter tyres about 4-5 weeks ago and I don't think this has cause the sudden downfall in economy plus I don't have a heavy right foot.

In the past week my 1.9 TDI has been drinking fuel, I put this down to using more strain on the car with using the lights,heater,heated seats,heated windows/mirrors .

Mine's dropped in the last week or two (from low-to-mid-50's to mid-40's on the way to work). Like you I put it down to the temperature, usage of lights, AC/heater, and heated mirrors, as well as a bit more traffic...

OP make sure you run the car on super plus unleaded and not the cheap stuff and change that temperature sensor and the sparkplugs.

False economy in an engine that size and power... If you pay 8-9p a litre extra I would expect 1-2mpg extra. It won't really do anything for the engine either as many tests on car programs have proven.

False economy in an engine that size and power... If you pay 8-9p a litre extra I would expect 1-2mpg extra. It won't really do anything for the engine either as many tests on car programs have proven.

If you check on the filler flap you will find that your car should only be run on super unleaded (98ron). I have found that sainsburys is the cheapest place for super unleaded. I filled up yesterday £131.9p. its not that much more and the car is much more responsive IMHO. Try it and see.

As for 40mpg i think that is respectable for this engine. Mine does no better. I once managed to get 49mpg on a 421 mile journey from Preston to the Outer Hebrides. Round town and on the daily commute i reckon i get 35mpg at best. But i do have a heavy right foot. Lol

Edited 15 December, 201114 yr by metzyman85

False economy in an engine that size and power... If you pay 8-9p a litre extra I would expect 1-2mpg extra. It won't really do anything for the engine either as many tests on car programs have proven.

This is bad advice, I'm speaking from personal experience please try and do the same rather than trotting out urban myths and hearsay.

Engine size has nothing to do with fuel requirement, this particular engine is 1.4 litres and it produces 100 bhp, it manages this due to a very high compression ratio and relatively long cam duration, it is the high compression which requires the higher octane fuel otherwise the ECU is forced to retard the ignition in an attempt to prevent pinking, this ignition retardation causes a dramatic reduction in torque at lower rpm and forces the driver to thrash the car harder and use more fuel, the pinking also erodes the sparkplugs which is why I recommended the OP replace them.

I don't know if I've got the wrong end of the stick here, but I just thought I would put my 2 pence in. 95 RON is what is recommended for this engine, any less than this and you wouldn't be getting the performance and economy benefits available, any more than this and you are unnecessarily paying more for fuel that you aren't utilising, the engine will not be able to make any use of the better quality fuel and you will not notice an increase in performance or economy. This is factual information provided by car manufacturers.

I don't know if I've got the wrong end of the stick here, but I just thought I would put my 2 pence in. 95 RON is what is recommended for this engine, any less than this and you wouldn't be getting the performance and economy benefits available, any more than this and you are unnecessarily paying more for fuel that you aren't utilising, the engine will not be able to make any use of the better quality fuel and you will not notice an increase in performance or economy. This is factual information provided by car manufacturers.

Unfortunately for the parsimonious this particular engine DOES benefit dramatically from running on a higher grade of fuel, please see above.

It is the advice of the vast majority of owners of THIS ENGINE ONLY on these fora that it be run on superplus unleaded for reasons of economy, performance and especially reliability.

You also find that Vpower has all sorts of cleaners in it aswell, does wonders for the injector(s)

I hear your opinion, however surely it is your opinion that is "urban myths and hearsay", manufacturers clearly state that running better quality fuels on engines not designed to utilise them provides no benefit, that is no performance, economy or reliability benefit. Manufacturers obviously put their vehicles through extensive research and development and perform testing with industry experts monitoring and tuning to try to get the most out of their vehicles, after all they all want to try and be "the first" and "the best" in their respective fields. If there was a benefit from using higher octane fuel, they would say so.

I'm not saying that you or anyone else is wrong, it is after all your opinions based on your experiences, but you can't deny that facts are indeed facts. I'm not going to get into argument over this, so I will reply and leave it at that, but my advice is to put what the manufacturer recommendeds into your vehicle and no more, unless you want to pay more for no gain.

You also find that Vpower has all sorts of cleaners in it aswell, does wonders for the injector(s)

Manufacturers also recommend not to use additives. In reality it doesn't really matter where you buy your fuel from, but I personally stick to the same RON as the knock sensor can get confused when the two RON's mix together in the tank.

I hear your opinion, however surely it is your opinion that is "urban myths and hearsay", manufacturers clearly state that running better quality fuels on engines not designed to utilise them provides no benefit, that is no performance, economy or reliability benefit. Manufacturers obviously put their vehicles through extensive research and development and perform testing with industry experts monitoring and tuning to try to get the most out of their vehicles, after all they all want to try and be "the first" and "the best" in their respective fields. If there was a benefit from using higher octane fuel, they would say so.

I'm not saying that you or anyone else is wrong, it is after all your opinions based on your experiences, but you can't deny that facts are indeed facts. I'm not going to get into argument over this, so I will reply and leave it at that, but my advice is to put what the manufacturer recommendeds into your vehicle and no more, unless you want to pay more for no gain.

No.

My 'opinion' was the same as yours, empirical evidence obtained during the last two years of my ownership of this car has altered my stance. My previous car was a VR6 and that showed no benefit running on superplus despite VW stating a 4 Nm torque increase in the handbook, in practice it was unnoticeable and therefore not worth the expense.

An opinion is subjective, experience is objective.

I don't know if I've got the wrong end of the stick here, but I just thought I would put my 2 pence in. 95 RON is what is recommended for this engine, any less than this and you wouldn't be getting the performance and economy benefits available, any more than this and you are unnecessarily paying more for fuel that you aren't utilising, the engine will not be able to make any use of the better quality fuel and you will not notice an increase in performance or economy. This is factual information provided by car manufacturers.

I think you will find that the manufacturer does recommend running this engine on super unleaded 98 ron as stated in the handbook and also on the fuel filler cap. this is only the recommended advice for the 1.4 16v 100hp engine and none of the other 1.4's.

Super unleaded 98 is indeed recommended by the manufacturer for this engine.

Well there you go then, if it's what the manufacturer recommends, use it! It's not rocket science is it?

I have a 2007 1.4 16v 100Bhp Elegance one of the last to come off the production line before the facelift.

It states on the fuel filler cover "Use unleaded fuel that conforms to 95/98 RON"

Nowhere does it state that only 98 should be used, it runs perfectly on 95 juice and I am happy with that.