Drop in mpg???

[faboka vrs]

I think I may have a fueling issue as I'm now struggling to get more than 310miles out of the tank. Thats from fill up to fuel light coming on. In the past 380-400 was average.

Now a few weeks ago the fuel light had came on and not long after the car was struggling to start. Then on the way to get fuel it was like I was running out of fuel. Strange as the light had not long been on. Say 10 miles or so. So a fill up of shell (before was tesco) and it seemed to have solved the driving problem but still didnt seem to start like it did.

A Couple of days later I had a new set of tyres fitted and went back to the oem 205/45 size from 215/40. Then after that it got a 10K service were a boost leak was found and fixed.

Then that tank lasted 350m. Thinking the boost leak may have caused the decrease in mpg I didnt think much of it. Now the last tank has only lasted 310miles.

Any ideas?

[ScoobyChris]

What tyres did you have fitted? Mine has been down 5mpg across the tank for the last two fillups after my new Falkens were fitted, but I filled up again on Thursday and after a good couple of 150 mile blats, economy for that tank seemed to be back up to normal. Current tank seems to be going the same way too, so I'm just putting it down to one of those things!

Chris

[mannyo]

Changed the MAF recently?

[faboka vrs]

Originally Posted by mannyo

Changed the MAF recently?

Nope. Engines not been altered except for the boost leak.

Was thinking about the tyres as well chris but to be honest I think its a bit too extreme. A normal drive to work would record 52mpg. I now struggle to get 41mpg. mpg was never that bad on the michelins or falkerns. Both were std sizes.

Could the fuel filter be clogged. Dont think its changed as part of a 10K service.

[des_pd_ tdi]

Originally Posted by faboka vrs

Nope. Engines not been altered except for the boost leak.

Was thinking about the tyres as well chris but to be honest I think its a bit too extreme. A normal drive to work would record 52mpg. I now struggle to get 41mpg. mpg was never that bad on the michelins or falkerns. Both were std sizes.

When I had new tyres fitted all round my MPG dropped considerably till the tyres were worn in, 1000 of use and MPG was back to normal. Also check the tyre pressure this can have detrimental effect on MPG.

Des

[faboka vrs]

After reading this http://www.briskoda.net/forums/fabia...?highlight=maf I think I'll get vag-com out and do some logging.

[viewer]

Sounds like the dross from the bottom of the tank could have got into the filter. Try running fuel through drain on bottom if no new filter handy - beware you need a container to hold a litre or it will spill. They are normally changed at 40K, but I do air, fuel, pollen at 30 just to be safe.
Best of luck
V

[ric04vrs]

just changed my filter at 41k , not a bit of debris in it , even though i've run it to 0 miles range , might be worth checking to see if there is any dirt in it

you could be right with the MAF though , has the performance dropped ?

tyre pressures ok ? no brakes binding ?

[faboka vrs]

No performance drop. Original idea was the fuel filter. Not got time to check the maf tonight so thats another day. If they isnt it I'll change the filter next.

[bryand]

I've had a subtle clutch slip for a while now. It only shows up on the gauges when severely provoked, but my fuel economy has dropped by about 6 mpg. I'm having the clutch replaced tomorrow, so we'll see if that was the culprit. You sure your clutch is 100%?

[ric04vrs]

Originally Posted by bryand

I've had a subtle clutch slip for a while now. It only shows up on the gauges when severely provoked, but my fuel economy has dropped by about 6 mpg. I'm having the clutch replaced tomorrow, so we'll see if that was the culprit. You sure your clutch is 100%?

interesting theory BryanD , lets us know if the consumption gets better with a new clutch fitted

[faboka vrs]

Originally Posted by bryand

I've had a subtle clutch slip for a while now. It only shows up on the gauges when severely provoked, but my fuel economy has dropped by about 6 mpg. I'm having the clutch replaced tomorrow, so we'll see if that was the culprit. You sure your clutch is 100%?

Interesting but cant see how it would happen over night like mine. But keep us informed. Not had clutch slip for a while now. Just the DMF vibrations

So far my bets are on either MAF or fuel filter.

[blueheart]

Originally Posted by ScoobyChris

What tyres did you have fitted? Mine has been down 5mpg across the tank for the last two fillups after my new Falkens were fitted, but I filled up again on Thursday and after a good couple of 150 mile blats, economy for that tank seemed to be back up to normal. Current tank seems to be going the same way too, so I'm just putting it down to one of those things!

Chris

My mpg dropped by abour 3 mpg when moving from oem Contis to Eagle GSD3's. I can feel the increase in rolling resistance but it's more than compensated by the better grip, both wet and dry, and generally better alround feel.

[faboka vrs]

Well I was getting 30mpg for my journey round town.

[ScoobyChris]

Originally Posted by faboka vrs

Well I was getting 30mpg for my journey round town.

You haven't bought any new footwear have you

Chris

[bryand]

Originally Posted by faboka vrs

Interesting but cant see how it would happen over night like mine. But keep us informed. Not had clutch slip for a while now.

Just got back from Jabba with severely dented plastic and a new organic clutch. 51 mpg on the way there and 56.8 on the way back. Also much more 'attack' to the driving experience and the clutch biting higher up the pedal travel.
I think clutch deterioration really can sneak up on you. (Having said that, I've got the old parts they took out, and there isn't much sign of anything abnormal.)

[faboka vrs]

Well just done a few wot with vag-com to measure the maf. Cant say anything looks strange with the results.

Next step. Fuel filter.

[ric04vrs]

Originally Posted by bryand

I think clutch deterioration really can sneak up on you. (Having said that, I've got the old parts they took out, and there isn't much sign of anything abnormal.)

when we were doing the DMF/clutch recall on the Galaxy PD130 , some of the clutches that were changed were still like new even after quite high mileages

[Neo_VR]

My clutch is f**ked...

yet i can still easily manage 45mpg when hoofing it.. and 55-60 on a run

I usually get 500-550 out of a tank.. thats not hangin about either

[53FabiaVRS]

I had my brake fluid changed yesterday and I had a drop of 10 mpg. I checked everything and it turned out my handbrake was binding slighty. So I adjusted it and my mpg is back up to what it should be. Might be worth a check?

[faboka vrs]

Right fuel filter has been changed so lets see how the next tank goes.

Before last night (change of filter) I had a couple more events of the engine taking longer to turn over.

[des_pd_ tdi]

Originally Posted by Neo_VR

My clutch is f**ked...

yet i can still easily manage 45mpg when hoofing it.. and 55-60 on a run

I usually get 500-550 out of a tank.. thats not hangin about either

I know we've had this debate on here before but how is this possible?. When I brim my tank I usually squeeze in 43 litres, that's after releasing the pressure 3 or 4 times using that button inside the fuel neck. How many litres can you get in the tank?

Des

[Chrispy]

Is there an easy way of doing that, like can you hold the pressure release button down whilst filling the car, or is it always a stop start procedure?