182 MPG only in the 20's

[BlakeTillz]

First of all, sorry for another MPG thread. But my mpg will not go over 25 im driving it nice and steady and not ragging it about, changing gears begore 3000 revs. Usually it goes from 21 to 23 then 25 if no traffic What could be the problem?

 

[Edges]

What's temp needle like? Gets to middle of the gauge and stays there? If not get a thermostat replaced and also look at changing the lambda sensor precat.

 

[MicKPM]

Absolutely anything... coolant temp sensor, H02 Sensors, MAP sensor, or even something like badly blowing exhaust, incorrect timing or general poor engine condition.

Needs properly looking at to say for sure but that is wrong.

 

[BlakeTillz]

Im changing thermostat as im doing a coolant flush and refill on tuesday as its prob not been changed since 2005. But the needle is sitting a little under the middle. Ive got a ktec exhaust on with de cat, so the lambda near exhaust is not screwed in just cable tied so its out the way. Shall i switch them around? Where could i get it properly looked at? Dont fancy renault as they bit expensive

 

[klm182]

i was getting 14 mpg at worse.. failed the mot,, put 2 new lambda sensors on,felt like a new car..
then past new weeks temp gauge wouldn't go to dead centre..mpg went down abit..think it was running cold.
got new temp sensor on.. back to mid 20s round town.. mid 30s or more on motorways..
i got 2 lambda sensor from europarts £110.. bosch ones..Renault wanted £110 for one..

 

[BlakeTillz]

Im only using one lambda as i got decat, so guessing just need to swap them over and see if anything changes. Going to get new cts aswell as its prob never been changed

 

[MartinR]

Get it checked over instead of chucking money at it changing parts that don't need doing.

 

[BlakeTillz]

The stat is getting changed anyway, as i need new coolant it, Fred said needs to be changed as it prob not been done since 2005. Swapping lambdas is a free job, if any of them things he, then happy days. If nothing changes i will get it checked. Im really sure its my front lambda causing the mpg to be low. Its weird, im not using alot of fuel its just on the trip comp the mpg and average mph is just so low.

 

[.J.a.m.e.s.]

Id get it looked at to diagnose the problem

 

[rsRob]

Is the car car running rough, hesitating etc?

Before spending any money, get the car in the air and try to turn all four wheels by hand. (Out of gear / hand brake off obviously). Sticking calipers on mine has caused poor mpg on a recurring basis.

 

[scotty10]

Why can one lambda cause so much more trouble than the other ?

 

[George182]

Why can one lambda cause so much more trouble than the other ?

The pre-cat Lambda adjusts fuelling - the post-cat lambda just monitors emissions.

 

[BlakeTillz]

Is the postcat the one that goes into the cat but if you have decat you leave it out?

 

[scotty10]

Cool, are they both the same ? I'm after a pre-cat one and they sell for £30 upwards.

 

[klm182]

Cool, are they both the same ? I'm after a pre-cat one and they sell for £30 upwards.

both the same.. I got my 2 from eurp parts

 

[BlakeTillz]

Is the postcat the one that goes into the cat and you take it out when you decat? Cus my mpg is like 24. Proper crap, ive changed thermostat cus it needed doing but guessing its the precat I need to buy