Fuel Consumption

[Wendelspanswick]

Back in November 2016 three changes occurred to my Renault Trafic van, I put stupidly fat lower pressure tyres on the front to enable me to drive off road to my barn, I made and fitted a set of roof bars so I could transport long lengths of timber and the Mass Airflow Sensor died.

Before these events I'd stick 80 odd litres of diesel in when the low fuel light came on and it would get me between 620 to 640 miles.

When the engine management light came on indicating the MAS had failed the range dropped to 440 miles to a tank. The MAS was replaced and the range went back up to 480 miles to a tank, no where near the 600+ I was used to but I put this down to the fat tyres and roof bars.

I tend to fill up every couple of weeks and I started to notice that each time I filled up the range increased slightly, till I got to the point this week where I managed 617 miles on a tank. Almost back to normal

Nothing has changed apart from my stupidly fat tyres have decreased in circumference slightly with wear but the roof bars are still on and my driving style and routes haven't changed.

I can only assume that since replacing the MAS that the ECU has been tuning the engine for maximum efficiency in small increments over the space of about 12 tank fulls till it's almost back to normal?

So my question is is there any way of speeding up the process if it happens again on this or any other vehicle I get.

 

[armalites]

Depending on the vehicle some diagnostic tools can reset the adaptions. Some vehicles also have a a default program and will still run with the sensor disconnected. Landrover TD5 is like that, I've seen one that was gutless but didn't log any errors because it must have just been in spec. Disconnected it and it drove perfect after.

I suspect there is also point that when you start noticing things like this you drive more economically whithout realising

 

[pedrobedro]

The MAF sensor went on our old Berlingo 2.0hdi and it would not rev or pull. I disconnected the sensor and it went like normal and didn't put the engine light on. I didn't check the mpg and when I fitted the new sensor a couple of days later I couldn't really tell any difference in performance. Did you have the code removed after you fitted the new sensor ? That might have some effect on it.