1.4 3cyl TDI Economy

[SteveB]

Hi,

Have a 2001 plate Polo (same engine as Lupo), which is giving ****e MPG, just nudging 50 on a motorway run sat at 65/ 70!

I know they are meant to do at least 60/ 65mpg ave. and can hit 70 on a good gentle run so I'm pretty sure there is a problem.

Performance seems to be ok but since the car is new to me I have no comparison.

I have replaced all filters along with an oil change etc. Did have a MAF fault and have replaced that leaving a clean bill of health according to VAG COM, i.e. no faults. Running gear is all fine.

Nothing else suggests a problem with the engine, no white smoke etc. Starts fine.

Does anyone have any ideas or has anyone come across this themselves?

Am yet to have the chance to give the EGR and intake a good clean out to see if there is excessive crap in there, but other than that I'm stumped..

Any help would be great, because at the moment I might as well be driving a PD130 golf or similar - the Polo was meant to be a cheap option on fuel!

Thanks in advance to all.

Steve

[nfbr]

50mpg is perfectly acceptable for an AMF 1.4 TDI engine in a polo...

Don't forget VW only got 65mpg because they tested it in perfect windless conditions at 55mph in Fifth gear...

[billy]

my loop tdi does about 200miles to £20 thats about 16miles aday to work

ive noticed as its been freeeeeeeezing that its not been as good as its not getting up to temp

billy

[nfbr]

My lupo TDI used to take forever to get upto temperature also.

[jon_273]

I have replaced all filters along with an oil change etc. Did have a MAF fault and have replaced that leaving a clean bill of health according to VAG COM, i.e. no faults. Running gear is all fine.

Did you replace with a Genuine VW MAF or a pattern part? Pattern parts have been known to cause poorer performance/fuel consumption. Also what fuel do you use? You will get better MPG from Shell fuel that you would from ASDA.

1.4 TDi's do not like the cold at all, they take ages to warm up and seem to use more fuel when its cold or wet. I got worse mpg than usual on a run recently but I have put it down to the weather.

[billy]

My lupo TDI used to take forever to get upto temperature also.

By the time i get to work (half hour) the guage is not got to 70 (quarter) am driving in hat and gloves

when it was proper cold last week, i had half the rear seat folded down, i put a small elec blow heater in the boot

with a timer plug on the end of an extenstion lead into the garage, set for half hour before i left,

the car was the only one in our close free of snow in the mornings. it made it abit more bareable untill the cld set in.

Yes i did unplug every thing before leaving. before someone says.

billy

[SteveB]

Replaced the MAF with a pierburg item, so not genuine. Measuring blocks seem ok on vag com, but I do take your point r.e. a potential to cause lower mpg... that is definately worth a shot when I have a little more cash.

Fuel is either Esso or Shell, so reasonable quality.

Thanks for the replies so far..

Edited January 17, 2010 by SteveB

[jon_273]

OK, only other thing I can think of at the moment is to run a fuel treatment through it. Forte Diesel Treatment is very good, I usually use a bottle when I do a service.

[franky]

Replaced the MAF with a pierburg item, so not genuine. Measuring blocks seem ok on vag com, but I do take your point r.e. a potential to cause lower mpg... that is definately worth a shot when I have a little more cash.

Fuel is either Esso or Shell, so reasonable quality.

Thanks for the replies so far..

I wouldn't worry about changing the fuel as derv car's aren't so sensitive to it, urban legends at work here.

I've done 1000 miles over the past 2 weeks, Its averaged 55.2mpg over the lot, I have a 90 round trip to work on a mixture of roads, I'm going to change my fuel filter to see if that would help raise it a little, although 55mpg ave seems to be the norm for these 1.4's 3cyl engines.

I drive at about 70-80 on the motorway.

The cold does lower the MPG a little as the fuel is thicker too.

If it was 10 deg warmer I reckon I should be hitting 58mpg. By comparison all my previous 1.9 vag tdi's have averaged 45mpg over the same journey, however my a6 estate will do low 50's on a motorway at 80mph. Obvously the lupo is designed for lower speeds.