PD150 Engine - Fuel Economy, What fuel economy?

Probs

Guest
Hi folks,

I've had a bit of search but I am desperate now for some advice. My Leon Cupra TDi has just managed 360 miles to tank. Just. I've just topped up wth 53 liters of derv and worked out that equates to about 30mpg.

I do a lot of stop stat driving but this fuel issue has been diving each week (My route/traffic patterns haven't changed in 6 months).

So far I have cleaned the MAF, changed the air filter and checked tyre pressures oh and removed the battery to reset the ECU. Ideally I would like some advice as to what to do next which would be cheap as I don't want to pour money at it (Ironically I brought a lower mileage newer car so I wouldn't have this problem)

Also how does the little fuel remaining counter work? How does it work the capacity out?

Any help you could offer would be appreciated :(
 

volvic

It's just water
Jun 28, 2008
791
0
House of Batiatus
fuel filter would be my next bet.

Have you ever managed to get more than 360 miles from the tank? You need to remember as the temperature drops you will sip more fuel. Also stop start driving is going to be pants regardless of it being a petrol or diesel.

I wouldn't trust the digital counter on how many miles you have left, the gauge is more true in my opinion.

I can get roughly 450miles from mine with a fair bit of stop start driving to work and back.

Do you take yours on a trash every now and then?
 

Probs

Guest
I used to get 400 at least round town 450 easily when I first got it but I was doing less town mileage. I never use the fuel thingy to tell me the true mileage I always use the trip counter but normally I find the fuel thingy accurate within about 20 miles.

The car gets a good run normally on weekends as I do a bit more motorway work or take it out to stretch its legs.

Like I say my routine is quite static and nothing has changed a huge amount to suggest this huge drop in mpg. Just plain weird.

I might have to take a look at the fuel filter, are these easy to change do you know?
 
Jan 11, 2005
680
0
Barnsley
I got under 300 miles to my last tank in my Ibiza Cupra tdi. I've put it down to the bad weather, warming the engine for 10+ mins whilst clearing glass and driving at much lower speeds will all contribute. If your journey hasn't changed I bet the journey time has recently.

A full service will improve mpg though and check tyre pressures
 

NI3K

Active Member
Nov 19, 2009
58
0
is it a bit smokey on acceleration? maybe the maf sensor is knackered? i was getting similar consumption but changed maf sensor and now seems a lot better but im still on the first tank since then
 

Amituk

Guest
I used to get 60mpg on motorways and average 40+ around town.

You cleaned the MAF.. but it may actually be knackered.. Get it on vag com and check for fault codes.

Another thing that happens is the EGR setup gets all clogged but dont know if that will effect mpg that much.

Faulty MAF is the most likely cause.
 

volvic

It's just water
Jun 28, 2008
791
0
House of Batiatus
I got under 300 miles to my last tank in my Ibiza Cupra tdi. I've put it down to the bad weather, warming the engine for 10+ mins whilst clearing glass and driving at much lower speeds will all contribute. If your journey hasn't changed I bet the journey time has recently.

A full service will improve mpg though and check tyre pressures

big no no in my opinion. the engine takes much longer to warm up on idle for 10mins when you could have used that time driving slowly. if it takes 10mins to clear the screen fair enough have the car on, but I wouldn't ever recommend leaving the car running just to get it warm before driving off (also lets not forget it's illegal to leave a car running without the driver inside it)
 
Jan 11, 2005
680
0
Barnsley
lets not forget it's illegal to leave a car running without the driver inside it

Illegal! Who says that leaving the car running without being inside it is illegal?

In the cold weather I like to let the engine oil get slightly warm before driving so it has circulated around the engine and turbo by the time I drive it. That way the components have a nice coating of oil before any stress has been put on the engine. Other people will disagree with that method but I will continue to do that until there is undoubted evidence to suggest that it is causing more harm than driving immediately after starting the car
 
Jan 22, 2007
2,074
0
some may say lala land....
all over the newspapers and discussed in the mk1 area, it is known to be illegal leaving a car running with nobody in it. even to clear the windscreen of ice.

best way to warm car up is to drive it.
change at between 1500-200 until nice and warm, which is always after the water temp reads 90, then start to use it more.
 

Hobbiniho

Active Member
Jan 17, 2009
545
9
shetland/ Aberdeen
Illegal! Who says that leaving the car running without being inside it is illegal?

i suspect what he was trying to say is that it is illegal to leave the car unattended when running, if you were standing next to it then that is not illegal but if you go and leave it that is illegal, also if its stolen your insurance wont pay out
 
Jan 11, 2005
680
0
Barnsley
Highway Code Rule 123
The Driver and the Environment. You MUST NOT leave a parked vehicle unattended with the engine running or leave a vehicle engine running unnecessarily while that vehicle is stationary on a public road. Generally, if the vehicle is stationary and is likely to remain so for more than a couple of minutes, you should apply the parking brake and switch off the engine to reduce emissions and noise pollution. However it is permissible to leave the engine running if the vehicle is stationary in traffic or for diagnosing faults.

After doing a bit of digging I found the above. As I have a private drive where the car is parked, I can leave it running and unattended and it isn't illegal in this case. Yes, the insurance won't pay out if it is stolen but I live in an area where the only people who walk any where near my house are the postman, neighbours and ramblers so I'll take my chances
 

mac magic

Guest
Hi folks,

I've had a bit of search but I am desperate now for some advice. My Leon Cupra TDi has just managed 360 miles to tank. Just. I've just topped up wth 53 liters of derv and worked out that equates to about 30mpg.

I do a lot of stop stat driving but this fuel issue has been diving each week (My route/traffic patterns haven't changed in 6 months).

So far I have cleaned the MAF, changed the air filter and checked tyre pressures oh and removed the battery to reset the ECU. Ideally I would like some advice as to what to do next which would be cheap as I don't want to pour money at it (Ironically I brought a lower mileage newer car so I wouldn't have this problem)

Also how does the little fuel remaining counter work? How does it work the capacity out?

Any help you could offer would be appreciated :(

Hi

I did notice my MPG slip a bit during the cold weather. However I was struggling to average any more than 45-47 on the Comp (I only do steady 25 mile/A road runs each way to work) when I usually get 50.

I checked my tyre pressures etc, but at the weekend I changed my discs and pads all round and I have now got my 50 MPG back (maybee and bit of a sticking brake!)

Even with the old blast to clear its lung my 04, 115K, tdi 150 always does 500 miles before the fuel light comes on (worst 490 miles best 550 miles).
 

Andrewcupra TDI

Resident Desk Jockey
Apr 30, 2008
3,282
2
in the mountains ( Wales )
are you venting tho , to get that milage ,

gota say if i give it the beans i can quickly dispense a 1/4 tank like on sat night , showing a friend how dervs are quick these days and on a 10mile stetch , all gone :(


im also thinking that this winter diesel has something to do with it , more additives to prevent freezing etc
 

waftywoo

Active Member
Nov 18, 2004
73
0
i suspect what he was trying to say is that it is illegal to leave the car unattended when running, if you were standing next to it then that is not illegal but if you go and leave it that is illegal, also if its stolen your insurance wont pay out


The offence is called "quitting" and it is a £30 non endorseable ticket, and yes it needs to be on the road. On your driveway is fine but the Police have seen a MASSIVE increase in car thefts where the driver has left the car running to get it warm! Not worth it, I would rather be cold for fifteen minutes that £10k out of pocket! If you read your small print on your insurance it will say that your not insured if the car is taken with the keys and there is no force or theft of the keys taken place.

If you think that because you live in a village where nobody walks past that you wont get your cat nicked then think again. This is where the more expensive cars seem to be therefore the scroats get a left to the area, walk round and find a car. Again, not worth it.

I use a mix of dual carriageway punctuated by roundabouts then town driving to get to work and I get 450-480 miles from a tank. Plus I am usually late so end up driving quite hard.

Hope that helps.:)
 
Jan 22, 2007
2,074
0
some may say lala land....
are you venting tho , to get that milage ,

gota say if i give it the beans i can quickly dispense a 1/4 tank like on sat night , showing a friend how dervs are quick these days and on a 10mile stetch , all gone :(


im also thinking that this winter diesel has something to do with it , more additives to prevent freezing etc

how does one do venting? AND what is it?
not sure i ever have and always get 550+ out of a tank.
granny to work and trash home 2 out of 5 and always the same.
light on at 40miles left according to trip thingy, and immediate fill up. anything up to 55ltrs as well
 

Andrewcupra TDI

Resident Desk Jockey
Apr 30, 2008
3,282
2
in the mountains ( Wales )
you fill her brimmed , then pull noxxle pump out , the the left of filler neck is a little button like thingy , finger on it an pull towards you i think and will release aload of air , (venting )
you then get to squeeze more in , where this air is normally there for expansion in the tank (HOt /cold days etc )


there are the points to think about tho , if your cornering hard etc you may spill derv out through overflow , which could make road conditions greasy and affect other users like bikers etc

only really worth doing on long haul trips i suppose , ive yet to do it myself

ive only fully brimmed it plus & just topped a little more in ,

will do on up and coming holidays trip tho
 
Last edited:

zoheb

Guest
I get around 250 miles when the light comes on. I have always got that much since I got the car. I put it down to the fact that because mine is mainly town driving and leicester being very hilly.

oh got a 130 sport
 

Art0ir

TDi Ho
Sep 21, 2009
356
0
Newry
I've a 90 tdi and my mpg, according to the computer, seems more tempermental than a teenage girl.

I can do the same stretch of dual carriageway, at the same speed, after warming up for the same amount of time and get anywhere between 47-58mpg
 

Andrewcupra TDI

Resident Desk Jockey
Apr 30, 2008
3,282
2
in the mountains ( Wales )
lots of factors to throw in , like air temp etc


well i done 200 0dd in mine last nite on a very spirited drive and cleaned the 3/4 tank out :(

was late picking a quad up & was in such a rush got to llanelli in about 35 - 40 0dd mins :whistle:
 
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