1.9 TDI FR - Why so juicy?

[Nahguam]

Right, my readout for average mpg for more than 2000 miles averages at 60.1mpg

Everytime when i fill up i see how much fuel i've put it, how many miles ive done and calculate to see how well im ACTUALLY doing, to find out if im getting 45mpg, thats all.

I'd love to know why

My tyre pressures at 2 or so psi over recommendation
I carry no excess weight at all
I change gear between 1,950 and 2,200 revs
Poodle along accelerating slowly and never going over 60mph
I serviced my car about 500 miles ago, what on earth is wrong?

If someone can shed some light on the subject i'd be very greatful, thanks in advance

 

[Lowe]

The on board computer is quite slow at taking a reading - about once every two seconds. Now, in that time you could be accelerating enough to be using more fuel than the computer recorded at the last reading, but have stopped by the time the next reading is taken... so as far as the OBC is concerned you didn't accelerate or use any more fuel. Hence the optimistic reading. You'll only ever get an accurate reading if you're pretty much on a constant cruise with no change in accelerator pedal position.

 

[Nahguam]

The on board computer is quite slow at taking a reading - about once every two seconds. Now, in that time you could be accelerating enough to be using more fuel than the computer recorded at the last reading, but have stopped by the time the next reading is taken... so as far as the OBC is concerned you didn't accelerate or use any more fuel. Hence the optimistic reading. You'll only ever get an accurate reading if you're pretty much on a constant cruise with no change in accelerator pedal position.

Even though i'm talking about average rather than the instant readout? i thought i took into account all of that, even so, why should i only return 43-45mpg from something like this? lol

 

[zach225]

How many miles has it done?
When was the egr last cleaned out?
Has the inlet manifold ever been cleaned?
Do you have any boost leaks?

Have you disconnected the battery and started again?
Do you watch the live mpg figures to make sure you aren't labouring the engine?

Tracking and alignment all been checked?

Lots to look at

 

[Nahguam]

How many miles has it done?
When was the egr last cleaned out?
Has the inlet manifold ever been cleaned?
Do you have any boost leaks?

Have you disconnected the battery and started again?
Do you watch the live mpg figures to make sure you aren't labouring the engine?

Tracking and alignment all been checked?

Lots to look at

Cars done 62k
know nothing about the egr
Not a clue about the inlet manifold
Not a clue if i have boost leaks
No i haven't disconnected the battery, what can this do?
Yeah i do watch the live figures, i try to keep it as high as possible but whatever i seem to do when accelerating, they do drop low inevitably
and i checked the tyres often, there's no uneven wear so i don't see how the tracking can be out of alignment

 

[phillpotts92]

Your lucky mine reads at 47.1! I don't drive hard and its just been serviced running 30 PS I front 32 rear. Egr is gunne be cleaned out soon maybe tomorrow. Only thing I've done is drilled the air box so can't see that taking more fuel so 60.1 is amazing!

 

[zach225]

A boost leak would give an obvious hissing sound under boost and oil deposits on the around the joins for the intercooler pipes.

Driving these cars 'carefully' generally means that oil deposits build up in the egr pipe and inlet manifold ( both connected at the back of the engine). I'd seriously consider taking these off and giving them a thorough clean out. Google is your friend with this one. If you don't feel confident speak to a friendly mechanic and get a cash price, will just be a few hours labour. The oil deposits will be restricting the amount of air gettin into the engine meaning you would have to accelerate harder to draw the same air.

Disconnecting the battery for 15 mins or so will reset what the ecu has learning about your driving, it maybe overfuelling itself to suit your driving.

If you don't want to go down the cleaning route id disconnect your battery (making sure you have the radio code) and do at least half a tank of 'spirited driving'. It may be enough to kick some of the crap out and let it breathe better

 

[Nahguam]

A boost leak would give an obvious hissing sound under boost and oil deposits on the around the joins for the intercooler pipes.

Driving these cars 'carefully' generally means that oil deposits build up in the egr pipe and inlet manifold ( both connected at the back of the engine). I'd seriously consider taking these off and giving them a thorough clean out. Google is your friend with this one. If you don't feel confident speak to a friendly mechanic and get a cash price, will just be a few hours labour. The oil deposits will be restricting the amount of air gettin into the engine meaning you would have to accelerate harder to draw the same air.

Disconnecting the battery for 15 mins or so will reset what the ecu has learning about your driving, it maybe overfuelling itself to suit your driving.

If you don't want to go down the cleaning route id disconnect your battery (making sure you have the radio code) and do at least half a tank of 'spirited driving'. It may be enough to kick some of the crap out and let it breathe better

Saying that it does randomly whistle on tick over, if i gently press the throttle it goes, and will come back soon after it idles again, I have a weird knocking sound which i thought was the engine cover when engine is under load, e.g. going uphill pulling :S

I'm a mechanic myself but on excavators and touching the car scares me a little, i serviced it myself but thats as far as I dare to go, but if the egr clean out is a simple enough job i may be up for it along with the intake manifold but that seems like hassle if theres corrosion. Im well up for the battery disconnect though, when you mean spirited driving, do you mean giving a hammering? i do that every now and then just to stop it getting all clogged up once every 2 tanks or whenever i fancy it i suppose lol

 

[zach225]

Yeh give it a hammering lol

I Did my egr and inlet manifold, it's not a hard job by any means but it can be frustrating, you have to do a lot of it by touch, mine was very clogged.

That whistle at idle is just turbo whistle and perfectly normal, it's if you get a loud hissing under boost then there's a leak.

The knock you get is probably your front rear wishbones on their way out, very common and you replace them with solid cupra ones that won't perish

 

[FR_MATT]

how long is your normal journey?

 

[Nahguam]

Yeh give it a hammering lol

I Did my egr and inlet manifold, it's not a hard job by any means but it can be frustrating, you have to do a lot of it by touch, mine was very clogged.

That whistle at idle is just turbo whistle and perfectly normal, it's if you get a loud hissing under boost then there's a leak.

The knock you get is probably your front rear wishbones on their way out, very common and you replace them with solid cupra ones that won't perish

Ah i'll have to look through some tutorials etc

and yeah its definately not a hiss, its a whistle

as for the knock, maybe i described it wrong, it could be a clatter but i dont wanna say my car clatters because as a rule it doesnt, the noise isn't suspension related because i can be on a perfectly smooth road and it'll still do it, it sounds like a vibrating or something, really dont know what it is! lol. if my wishbones do go i'll make sure i get cupra ones though

 

[Nahguam]

how long is your normal journey?

well my journey to work everyday is 25 miles each way, with about 15 of them on dual carridge / motorway

 

[Jimlad86]

I would say 45 - 50mpg is about average for a TDI FR. I usually get that and like you my computer says 60mpg. They are useless!. Only goes above 50mpg on a LONG run.

 

[Ol' Timer]

Whenever I have checked mine it works out at about 43-45 mpg. I think that is about normal unless you drive up and down motorways all day.

 

[abbotsmike]

So far my measured average has matched up to the OBC readout, give or take 2-3mpg.
Around 45mpg, but there's not been that much motorway driving in there so far, and I do tend to kick the arse out of it fairly regularly.

Doing a run up to tremadog, wales fully loaded at the weekend, so will report back!!

 

[Jimlad86]

Seems to me that its hit and miss if you have a decent computer of not. Some report they are accurate and some report that they are total rubbish

 

[bald_eagle]

mine does about 48 mpg with 90% town driving so yours seems a bit thirsty considering the dual carriageway/motorway use which makes my average shoot up.

The computer on mine is surprisingly accurate considering what people on here say about them.

 

[samussamus1]

I had a "reading" of 78.2mph @ 60mph on the motorway for 30 minutes.

=/

 

[hoggy a]

i cleaned my sons egr out last week and fitted a smaller egr gasket,his mpg has gone up to 60mpg and he says its smooth to drive and alot more responsive

 

[747_727]

Are you checking what the actual average trip setting is saying not just the one that resets its self every 2 hours when you turn your engine off? And do you reset it every time you fill up?
My trip computer on my cupra tdi is within 0.4 of a mpg to what it is if I work it out manually.