Megane 1.5dci 54 - fuel cons down after battery change

[Roxy2]

I have recently changed my battery as the 'green' disc was not remaining green any more and with this cold weather weve been having didnt want to take the chance on a flat battery. The old battery was disconnected and a new one fitted abour 30 minutes later.

Since doing this the average mpg never exceeds 49.6. Up until this point I could always have an average of 53.2 mpg doing the same laborious drive to and from work.

I have read that disconnecting a battery for more than 15 mins can reset any fault codes (I no longer get an 'auto light fault' warning) and have also read that injectors need programming on some models?

Could it be that my injectors need reprogramming or is there something more sinister going on?

[direstraits]

I do not think that injectors need reprogramming, but the ECU might be 'learning' your driving style. I.e. if you're driving a lot of city driving after disconnecting the battery, your consumption will increase.

[Triumph232]

Hi, i have noticed my 1.5dci consumption has dropped slightly last few weeks, i think it is down to the cold weather as engine is taking longer to warm up.Mine is normally 53 but only getting 50, so i wouldnt worry about anything being wrong.

[davelowe]

Another thing that might be relevant is that the tyres don't get as warm so create more rolling resistance. Make sure they are inflated to the correct pressure when cold.

[-KJ-]

Did you actually measure how much fuel you've used at the gasstation or are you relying on the rather unreliable boardcomputer in your car?

[Roxy2]

To be honest no I havent measured the amount of fuel used recently as the onboard has always been fairly accurate when I have checked it in the past.