Poor fuel consumption

[497adam]

Fuel consumption on my Phase 2 172 seems quite low compared with what other members are getting. low 20s around down with careful driving, rising to around 30 on a run. It has recently been serviced and had cambelt kit ect. But didnt really improve much whilst being serviced garage checked diagnostic but it had no fault codes. Ideas would be appreciated

 

[maynard]

probably something to do with the lambda sensor.

try changing the front of cat lambda, cost approx 60-70 quid.

this normally helps.

 

[hipwell]

Is or getting up to full temperature? First thing I'd try if not would be the thermostat. Changed mine and fuel economy has improved greatly

 

[497adam]

I was thinking possibly lambda but thought that would of thrown up fault code?

 

[Fred@BTM]

who did the cambelt?

 

[497adam]

A friend did at his garage, he's done several( although not a renault specialist knows his stuff). Power better since but didn't really seem to help fuel consumption. Had new plugs (correct ngk ones), magnecor leads, itg panel filter and new manifold gasket. Car has done 54k. Fuel consumption was poor prior to cambelt. I don't know if I'm expecting too much fuel wise but everybody seems to get good figures when not thrashing

 

[Fred@BTM]

should do over 40mpg at 70mph easily, temp gauge just over halfway?

 

[497adam]

around half way on gauge, how quick do they warm up?

 

[Fred@BTM]

pretty quick waterwise, about 10-15min oil wise, does it rev to 7200???

coolant temp should be a tiny bit above half as you look at it

 

[497adam]

I have noticed that sometime rev limiter comes in at 6800 ish

 

[sideways danny]

sounds like you could do with a new thermostat. Worth looking at the operation of the lambda sensor too, they rarely throw up a code as they dont stop working entirely, just give wrong info to the ecu

 

[497adam]

Been out for a run on motorway, at roughly 70mph on trip was showing 40 to 41.5 mpg but temp was running just under half even after 20 min. Only came up to half way when I increased to over 80 mph.

 

[497adam]

Will try thermostat

 

[497adam]

Will try a thermostat to start, are pattern ones ok?

 

[hipwell]

I got a thermostat from gsf, 14 quid, works a treat !