Poor MPG after timing belt changed? 184.

[Aero843]

Hi , had a major service done in November, timing belt and pump changed, its remapped to stage 1 but I used to be able to pull 40-45 no worries on my commute to work, now its dropped to 37-40 per commute, it was done by seat themselves so I don't think they would've messed up the timing or anything like that (I hope) But not sure what the issue is. I don't think it'd be because of the cold as it was just as cold in November, anyone have any ideas? I get around 350-370 miles to a tank.. Tyre pressure is factory and i've tried it in sport and eco.

Thanks in advance for the help!!

 

[Rusty2k]

If it's driving okay then it could just be due to winter diesel, which is used from November to March. It has additives to help keep it stable at colder temperatures but this dilutes the fuel meaning you will perhaps see a reduction in economy.

Perhaps see if it improves over the next couple of months.

 

[SRGTD]

When I owned VW diesels, I used to see up to a 10% drop in economy during the months that winter diesel was on sale. So winter diesel could well explain @Aero843 ’s poorer fuel consumption - assuming the lower mpg has been happening since November and hasn’t just recently started happening.

 

[MATT RILEY]

350-370 miles to a tank.

In a diesel?
My god I get 560 to a tank in my 150TDI.

 

[MattN]

I once got 600 miles from a tank in my 1.2TSi petrol. I am upset with anything less than 550 in summer and 500 in winter.

 

[Jay5959]

Is it still mapped? There was a software update notice showing when I booked my 184 for an all in warranty inspection. They should check with you if you are happy to get it installed, but if they have just done it anyway while you were having timing done that could explain it. Just a thought. Others saying winter diesel, it could be, but 37mpg is not great even for city driving flooring it from traffic light to traffic light . Unless you’re constantly having dpf regens which tanks the consumption. I’d ring up seat and check with them as that’s poor economy for a 184. I had no noticeable change in fuel economy after getting the timing done on mine. Mix of motorway driving and city driving on my commute still well into the mid 40s mpg

 

[SuperV8]

How long is your commute?
I normally get 55 - 60mpg on my commute, not eco driving - 60-73mph and 27miles each way. If I drive less than 10 - 15miles the MPG is much worse.
Rain/Cold/DPF regen's & busy traffic all negatively effect this.
My MPG didn't change noticeably after my belt/pump change.

 

[Aero843]

Is it still mapped? There was a software update notice showing when I booked my 184 for an all in warranty inspection. They should check with you if you are happy to get it installed, but if they have just done it anyway while you were having timing done that could explain it. Just a thought. Others saying winter diesel, it could be, but 37mpg is not great even for city driving flooring it from traffic light to traffic light . Unless you’re constantly having dpf regens which tanks the consumption. I’d ring up seat and check with them as that’s poor economy for a 184. I had no noticeable change in fuel economy after getting the timing done on mine. Mix of motorway driving and city driving on my commute still well into the mid 40s mpg

Ye they done a software update after the service and never asked for permissions, got a full refund and the guy i got it remapped off put it back on for 50 quid so was delighted dpf regens id say once or twice a week maximum does that sound normal?

 

[Aero843]

How long is your commute?
I normally get 55 - 60mpg on my commute, not eco driving - 60-73mph and 27miles each way. If I drive less than 10 - 15miles the MPG is much worse.
Rain/Cold/DPF regen's & busy traffic all negatively effect this.
My MPG didn't change noticeably after my belt/pump change.

Commute is about 10 min motorway and 5 min backroad about 10 miles only, ill keep an eye on it as it starts to get warmer, thanks for your help

 

[bigbadjay]

Mpg always drops in winter petrol or diesel, it takes much longer for the engine to reach optimal temps thus runs inefficiently for a good 20mins on first start