Increased fuel usage...

[Willo9891]

Hey Guys,

Over the last month I've been noticing an increase in how much fuel my Golf is using. It's a MKVI 103 TDI. I put a set of 19's on when I first got it and noticed a slight decrease in my km's averaged per tank. I used to be able to give it a bit every now and then and still get quite excellent mileage out of it. But lately the only way to achieve this is by driving it like a nanna! It is serviced every 15,000 k's at my local VW dealer, and currently has approximately 49500 k's on it.. Any help as to why it's using more fuel would be greatly appreciated.

Cheers
Willo

[Diesel_vert]

Over the last month I've been noticing an increase in how much fuel my Golf is using...

... I put a set of 19's on when I first got it and noticed a slight decrease in my km's averaged per tank.

There's your answer... assuming there's nothing mechanically wrong with the car.


Bigger wheels and tyres means bigger mass, so more energy is needed to get them rotating.

Bigger tyres also means bigger width and performance tyres, which increases rolling resistance, so more energy is needed again.

19" wheels on a Golf also increases its ride height, making it slightly less aerodynamic, which also costs you energy through increased drag at highway/motorway speeds.

[gldgti]

There's your answer... assuming there's nothing mechanically wrong with the car.


Bigger wheels and tyres means bigger mass, so more energy is needed to get them rotating.

Bigger tyres also means bigger width and performance tyres, which increases rolling resistance, so more energy is needed again.

19" wheels on a Golf also increases its ride height, making it slightly less aerodynamic, which also costs you energy through increased drag at highway/motorway speeds.

I think the OP already covered that possibility.

Willo - you will/can get a million possible answers on here for something like you've described, including fuel quality, DPF clogging, faulty parts etc.

Tell us a little more about the specific circumstances of your increased fuel consumption - like where you fill up, how often, how much you drive, where/how its serviced etc.

If you can, take it to a specialist mechanic and get the car scanned with VCDS for faults. This is pretty much the most sensible thing you can do first off if its easy.

***EDIT*** since your in Gosford, I can even scan it for you on the weekend if you like. pm me if your interested.

[Diesel_vert]

I think the OP already covered that possibility.

Ah, he has indeed.

[Willo9891]

I think the OP already covered that possibility.

Willo - you will/can get a million possible answers on here for something like you've described, including fuel quality, DPF clogging, faulty parts etc.

Tell us a little more about the specific circumstances of your increased fuel consumption - like where you fill up, how often, how much you drive, where/how its serviced etc.

If you can, take it to a specialist mechanic and get the car scanned with VCDS for faults. This is pretty much the most sensible thing you can do first off if its easy.

***EDIT*** since your in Gosford, I can even scan it for you on the weekend if you like. pm me if your interested.

Thanks for the replies..

I usually fill up at woolies caltex at wyoming, usually fill up around every 5-7 days depending how many days in a row i am rostered to work, I drive to and from the eastern suburbs in syd for work so is about 180k round trip, serviced at central coast volkswagen in gosford, just a normal log book service.

Yer I knew with putting on bigger rims I would lose some fuel economy, but it wasnt much and I still got pretty good mileage.

I would normally hit 500k's or more before getting to half a tank.

[Transporter]

It can also be the error at the service station (assuming you go by the fuel docket). Some pumps are less accurate than others and it could be as bad as 50ml per L that's just over 2.5L less in the 54L tank if you fill up from almost empty. Try different servo.

[Willo9891]

It can also be the error at the service station (assuming you go by the fuel docket). Some pumps are less accurate than others and it could be as bad as 50ml per L that's just over 2.5L less in the 54L tank if you fill up from almost empty. Try different servo.

Nah I fill it right up everytime and go off the cars odometer...

[gldgti]

I have a mate that uses that servo for diesel a lot, no complaints from him really. (Same car as you too, even the same colour!)

Also, I'd just about rule out a DPF problem knowing the commute you are doing (same as me pretty much) so it might be something weird.

See you Sat.

[getjet]

My fuel usage went down when I cleaned the egr/asv. Not much but still went down... I wouldn't have thought it was this though given its only done 50k

[jazd]

I'd definitely be suspecting the dpf doing lots of regens. I'd also clean the intake and EGR but they shouldn't d be that bad at 50k