Excessive fuel consumption

[xmagneto]

Hi, I'm facing quite a serious problem regarding fuel efficiency. My Renault Megane II Berline 04 is doing 13/100. It should be doing between 6 to 9. Renault dealer is telling me that it's due to fuel quality etc.. but that's a very poor answer. I've checked with a car mechanic and oxygen sensor, spark plugs, air filter are all good. On the internet i heard about the injection computer might be at fault and may be i need to change the fuel pump.. please do let me know if you have any idea about why the fuel consumption is so excessive. Thanks.

[Stranger]

I read in your introduction post that you'd recently done the timing belt, are you certain that the car is timed up absolutely correctly?

[dimitrius]

if it wouldn't be timed correctly it would be in bits and pieces by now! air filter maybe? but still such a big difference indicates either a problem or an aggressive driver.

[joeishmather]

It could be out.. I had an Alfa 147 bought it with an issue, low mpg and poor acceleration, turns out the issue was the timing belt being out! Like you said I thought that the car would have exploded but apparently not..

[Stranger]

if it wouldn't be timed correctly it would be in bits and pieces by now! air filter maybe? but still such a big difference indicates either a problem or an aggressive driver.

Not neccessarily as it could be seconds out but not degrees out and would run but wouldn't be running perfectly, this could contribute to poor economy.

[xmagneto]

Thank you all for your replies. Well even before I had the timing belt done, the consumption was 11/100. Regarding the fact about "agressive driver", well I must admit that I'm not the coolest driver on the road especially on motorways. however most often i go to work, and i live in a city where i need to brake a lot, and rarely i can switch to 4th gear. 1st, 2nd and 3rd gear are very common because of traffic. I have noticed that on 4th gear the car does good but 4th gear on a speed of 60Km/h, i dont think that's reasonable is it?

[wanda]

I had a similar problem and it turned out to be the oxygen sensor.

[leonbwr]

I see this is an old post but i have had the same issue - bad fuel consumption and the front wheels run hot. When i took the calipers off they were stuck. Moisture managed to get under the seals over the pistons and they had a thin layer of rust on them. I rubbed this off with a rough cloth and then pumped WD40 under the seals. Problem solved and my fuel consumption is better than ever. ( I live 500m from the North Atlantic coast, so it must have something to do with the fierce storms we get and the car is parked outside ).