MPG std S2?

[AUDIS2avant]

Hi guys, am a bit interested here, what do you return to the gallon on the freeway and normal NOT kombined?

Did a full tank to germany and home 3 weeks ago and car did NOT do well
Speed was between 120-140 km/h and i did 6,9km pr liter that´s arround 14,5L pr 100km

i have just changed the lambda sensor and it got a little better but nothing noticable, any ideas?
MAF sensor maybe?

[Rusty]

I'm currently averaging 15mpg because every time I take teh car out I do a few 2nd gear WOT runs for analysis

On a cruise I'd expect 26 to 28mpg.

1 gal = 4.5 l

1 mile = 1.6km

so l/km to m/g = 4.5/1.6 = 2.8

so 6.9 x 2.8 = 19.3mpg, that's poor.

If you've not got a boost gauge then get one, when you're cruising you want to have minimal boost on, I also drive with the instantaneous mpg on the computer as you can maintain the same speed and get 25% more economy if you're carefult with the right foot.

Things that can affect FE are dirty MAF, Lambda, tired spark plugs, really dirt oil, air filter... just give it a good service if you've not done so

[AUDIS2avant]

Ok then hmm
oil and plugs are new and brand new KN-filter in box, i have cleaned the maf and rechecked it but there´s some oil in it constantly from the turbo i think (looks like it´s coming from the recirkulation hose)
I have a boost gauge and it almost NEVER come over 0,0 bar maybe 0,2bar and i have also the mpg on instant readout L/100km and always try to keep it under 12 so it should be ok, but it never shows right
One thing i have also noticed is that it doesent feel as quick as it should be

[Rusty]

Could be a boost leak then. Better get checking the hoses

[AUDIS2avant]

i have also checked that
But what are the difinition of a broken MAF sensor?

[Rusty]

Check the resistance on all temperature sensors?

Need to get a MAF in known working order and swap it over.

[AUDIS2avant]

"chesk the resistance on all sensors" yes but what does it have to say? working not working?

[Rusty]

Most of the resistance vs. temperature etc. graphs are on sjm autotechnic.

[AUDIS2avant]

Any help please?
Cant find my way arround i there

[johne]

You don't say how you measured the 6.9KM/L. If it was using the on board computer, they aren't that accurate and usually under read unless you've calibrated them.

Is your thermostat working well so you run with a water temperature of 87 degrees even when cruising on the motorway?

John

[AUDIS2avant]

i have measured it on liter i fill in the tank verce the kilometers the car has run between tanking, i.e 322km on 46Liter of fuel....

Even my toyota hiace goes longer then that

[AUDIS2avant]

Have checked the termostat today, and it´s brand new original one, so not much help there

[Rusty]

Is this a new thing or is the car new to you?

[AUDIS2avant]

I have just bought the car (3.januar this year) so the car is new to me.
Am thinking about just changing the 2 sensors (inlet temp and water temp to ecu) but there are 2 water sensors in the top, which one is it for the ecu? blue 4-pin? or 2-pin on the back of the top?

[Jonas_R]

If you MAF gets dirty with oil then it is properly the KN-filter that you are using? Is it dipped in oil? Or it could be the PCV system or turbo leaking oil fumes into the MAF hose.

I got a VAG-COM so if you want I can read out the fault codes on you car and also have a pressure testing kit. Because if you ain't seeing more then 0.2 bar boost then it seems your running mechanical boost. This could be because of a boost leak or perhaps a defective MAF.

You should change the water sensor with 4 pins also called the MFTS, but when you there you might as well change the other one.

If you ain't doing anything on friday and don't mind a drive to Værløse then we can have a look around 16.00 perhaps a bit earlier and see if we can figure out what the problem is.