Around 2k RPM, MPG to pot?

[pow]

My Sport TDi 130, when cruising around the 2k rpm make, I can't seem to make anything into the 50's on the MPG?

For example, cruise control, 75-80MPH = 47MPG at the very most? 1.9 - 2.1k rpm

45 MPH in 4th, again, in the late 40's? just under 2k?

Measured my expected MAF and actual MAF and that SEEMS to be OK, is there anything else that I could measure to see if it's a sensor (too much boost prehaps, injector problem etc?)

Beginning to piss me off, used to get the MPGometer well into the late 50's, now I don't have a chance!

Any ideas?

 

[Nath.]

That's not good, my petrol FR can manage low 40's.

Are you sure it's had a good service and had the oil/filter and air filter changed?

Are you sure the tyre pressures are correct?

What about the temp gages, do they all read normal. An engine that thinks it's still cold will run rich.

 

[james.l]

you might have a temp sensor gone which is actually differant to the engine gauge sensor, might be worth running a vag-com on it if you can.

 

[mhill]

Whats you milage?

 

[pow]

90k, Serviced recently (3-4k ago?), all new filters, new oil.

VAG-COM brings back NO faults apart from a climate control flap one.

Changed the CTS a little while a go - since then the temp gauge on the dash won't return to 50 (sits just above) but the car warms up fine - think the gauges is a normal ibiza problem anyway? Is it worth changing this again?

Tyre pressures are checked weeky (32 on the front, 30 on the rear), tracking done recently, I do run 205/40r17's but still, mid 40s using hardly any throttle is pish.

 

[pow]

On the 16s running 205/45r16's with the tracking to **** and a bent tie rod I used to be able to manage 60MPG crusing at 70-80 BUT that was a little while ago.

 

[Nath.]

you might have a temp sensor gone which is actually differant to the engine gauge sensor, might be worth running a vag-com on it if you can.

Agree, the engine has a temp sensor that sends a signal to the gage in the instrument cluster. It also has various other temp sensors that may not show a fault, these sensors could be reading just low enough for the engine ECU to over fuel but not actually show up as a fault with Vag-Com

From memory there is engine air intake temp, fuel temp and so on. good luck.

 

[pow]

I'll dig the old laptop out and get a few facts and figures up today.

On another note, the cruise control and the weather really don't seem to be helping things...

 

[george130]

Those figures don't seem too out of the ordinary to be honest...
Keeping in mind you get the best mpg at around 55-60mph, I would expect the figures your getting at 75-80?
Maybe if your in steady traffic, move into 5th gear (re: late 40's at 45mph)?
Also perhaps the usual things like sticky calipers, tyre pressures etc...?

 

[RossIBIZATDI]

Yeah your figures don't seem that bad. I've got just over 100k and had oil, filter and coolant done last week. My figures don't seem to have changed after it but they're 55MPG doing about 70-80 on motor way. On my trip to work which is stop start traffic on 30-40MPH roads is about 38MPG. Oh and I've got a FR TDI.

 

[pow]

Any other ideas?