Poor mpg in a 1.9tdi 130 sport

[Sp0oner]

In the last couple of months i've noticed the mpg drop a fair bit on my Passat. There are no error codes when I plug in VAG and there is no loss of power so ruled out the MAF need cleaning.

It was last serviced in July with just an oil change/filter.

The only thing that has changed is im obviously using the climate control a lot more in the cold weather but I can't believe that can affect the mpg so much? I thought it was only the air con when having cold on full blast that really hit the mpg?

The engine does sound 'rattly' at low revs but with no error codes it isn't obvious what is wrong. My local garage took for a drive, said power was fine but could hear the low rev rattle but with the bonnet up in the garage with them looking/listening they couldn't find anything obvious.

I know the undertray is loose and the engine cover isn't tight but the rattly noise is metallic as opposed to plastic banging/knocking.

Any ideas? MPG is at best low 40's and i'm driving it like miss daisy both round town and on the motorway. If I sit at 80 I struggle to get 40mpg on the motorway which is not right for a tdi.

[PeterB]

My MPG drops by about 10% in the winter - presumably because of fuel being changed to winter diesel. I have spent about 25 years recording my mpg for a variety of cars (I know its sad but its also compulsive). This is the first diesel I have owned and until I read about Winter Diesel on this forum (last winter) I also thought I had a problem.

Late last week I travelled back from Kettering and at a steady 70mph my 130 tdi se was returning about 48mpg according to the trip computer. I usually find the trip a bit optimistic compared with actual consumption so I think just over 40mpg at 80mph is probably about right.

Peter

[Panzerdriver]

There has been a lot of debate on mpg on 130 tdi's on this forum. Have a look using the search engine to see previous threads.

I am on my 2nd 130 tdi sport and the mileage does vary but if i drive the car normally ie not thrashing the nuts of it i will see on a run an average of 48 mpg+.
I normally do 500 miles+ a week mainly A roads and Motorway driving on the Motorways at 80 ish.

I do find that if i hammer the car hard for the first 20 miles or so on the motorway then i will struggle to get 42 mpg but without the heavy right foot to start with then 48 is easily achieved.
I personally have never got less than 500 miles from a tank with the best being 650 (this just recently)

My last sport had 133k on the odo and my latest one 71k and mpg on both is very similar so from an average mpg point of view there is very little difference.

The metallic rattle should not be there but you will really need to check all the ancillaries, tensioners, mountings etc. Diesels are noisey (some quieter)by nature but not metallic so something is amiss.

[Sp0oner]

Well it is a weird one, been driving the last 2 days with the climate control turned off, no demisting the windows or anything. Whilst i've been leaving that off the mpg has been much better. Got 51mpg on a 20 mile run out today and then 48mpg on the way back with the fuel computer reset for the way back.

Yet all the time i've been driving round with the climate control on i've been struggling to get 40mpg I really can't believe the climate control can use that much fuel unless there is something wrong with it?

It's getting a test drive by the head technical bloke at my local dealership in the new year when he is back from leave to get a specialists opinion on the rattle/noises and on the fuel consumption. Not charging me for it unless it gets booked in for anything to be checked further which i'm quite pleased about (previous Octavia couldn't be looked at by Skoda without incurring a £40 charge for sticking it on the computer no arguing). I explained to VW garage i've stuck it on VAG.COM and got no errors and have had no warning lights on the dash and they were happy to accept that and not insist it goes on their computer.

[stonedagain]

My MPG drops by about 10% in the winter - presumably because of fuel being changed to winter diesel. I have spent about 25 years recording my mpg for a variety of cars (I know its sad but its also compulsive). This is the first diesel I have owned and until I read about Winter Diesel on this forum (last winter) I also thought I had a problem.

Late last week I travelled back from Kettering and at a steady 70mph my 130 tdi se was returning about 48mpg according to the trip computer. I usually find the trip a bit optimistic compared with actual consumption so I think just over 40mpg at 80mph is probably about right.

Peter

The accuracy of the trip is not a legal requirement by law, but the odometer & the speedometer are, within a specified percentage! If, for instance, you do a journey of a known distance, zero the trip & record the odometer reading, then at the end of the journey compare the mileage difference between them. I work for a car manufacturer!

[Panzerdriver]

I leave my climate control on auto all the time so if your fuel consumption changes that much each time you turn it off then they may well be a problem with the system.

Do you notice any change in the engine performance when you turn the climatronic system on and off.

I used to have a Calibra turbo which had a well worn air con compressor and there was a huge difference in power with it selected on, it actually felt like the brakes were stuck on so instead of 204 bhp it felt more like 130 so in the end i never used it.

[minty0_10]

500 miles to tank i can dream i suppose 40 mpg ive been seeing for the last year.
so me minds made up its being sold early next year and im going back to my old 110 afn tdi passat a much better car and 50+mpg and no real difference in performance either