poor mpg (lambda)

[hipwell]

The last few months I've been averaging 28mpg driving like a granny round town, so I was thinking it may be a lambda problem. However on the motorway at 65 I still get a very good 43mpg.

I used to get 32 town driving so thought about buying a new 02 sensor but if the motorway mpg is still good then surely the sensor must be functioning ok?

Car has had a full service inc ngk plugs, thermostat from Renault etc. It doesn't feel down on power really and runs fine.

 

[davo172]

http://www.cliosport.net/forum/showthread.php?642984-Bosch-Lambda-(O2-Sensor)-Clio-Ph2-1*2-PT2

 

[Austin-182]

Changed mine a couple weeks ago, went from 26mpg to 38mph. Get high 40's on motorways now

Well worth changing. Im not sure if its actually possible, but my car feels much better and pulls better.

 

[hipwell]

Yeh I see people getting much better mpg from changing the lambda, however my motorway mpg is perfectly fine which makes me think the sensor could be ok.