mpg has dropped since service!

ianbar0

i have a golf 1.6 tdi match. i took her in for her first service week thursday ago. i have only done work commutes which is only 3 miles but usually to work i can do nearly 70mpg and back just over 50mpg but this week i have been down to less than 50mpg there and 30 odd on way back. i have not called the garage yet as it is going back for a couple of little cosmetic jobs anyway in a week or so. i will mention it when they call to book it in but im thinking its simply a computer issue as the fuel does not seem to be dropping too fast in comparison. any ideas?

marlot

Sounds like the fuel computer was being over-optimistic before the service. I can't believe the car was genuinely getting 70mpg on a commute. Maybe there's been a software upload.

The only way to reliably get mpg figures is to fill the tank, run the car, fill the tank - and work it out from the number of miles travelled and the fuel needed to top it up.

reeac

Any idea what's involved in that first service? Presumably nothing too major but that might provide some clues.

ridethelightning

Not related to your mpg drop, but does your golf have dpf? From a quick search I think it may do. If this is the case you are going to have some major (and expensive) problems very soon if you are only using the car for a 3 mile commute! This should have been explained to you when you bought it but many dealers will not inform you that you have to drive fast (motorway, dual carriageway) with the engine hot for 10-15mins about once a week to clear the dpf. I would advise you to read up on it as it will not be covered under the warranty as the manual says it must be cleared regularly.

ianbar0

yeah might have to have a look at what they have done! thought it was not anything major. as for the mpg before, its basically all downhill to work hense i would hope i was getting 70mpg! especially with over a mile of coasting! i think they may have messed something when plugged in, its odd because while the trip computer is reading very different im not sure the fuel pointer is moving as same new rate.

DUTR

ianbar0 wrote: »

yeah might have to have a look at what they have done! thought it was not anything major. as for the mpg before, its basically all downhill to work hense i would hope i was getting 70mpg! especially with over a mile of coasting! i think they may have messed something when plugged in, its odd because while the trip computer is reading very different im not sure the fuel pointer is moving as same new rate.

If you think this and think that and the techs are so incompetent, then why not service the vehicle yourself?
The harsh reality is, you were never getting 70mpg from the car, and the 50mpg displayed is closer to reality (all be it still optimistic) I had charge of a 1.4 audi a3 and whilst quoted 68mpg, the reality was 45mpg certainley not twice of my gti. Not sure why folk complain of desiel prices if they are so economical?

roddydogs

Never go by the on-board computer, their usually miles out.

ianbar0

well that may be true! will still get it checked out, not bothered if its reading wrong just bothered if tis suddenly doing a lot less mpg!

pendulum

Garages hate this, they do some work then a customer returns with a completely unrelated issue that "wasn't there before" and expects them to sort it out.

We upgraded RAM in a computer once and the customer came back a couple of days later with a virus that "definitely wasn't there before I brought it in"...

It happens in every profession / area of work. After a customer's had work done they'll pay more attention and notice things they didn't notice before, and then they think it must be the fault of the person who last worked on it...

The_Turner

ianbar0 wrote: »

well that may be true! will still get it checked out, not bothered if its reading wrong just bothered if tis suddenly doing a lot less mpg!

How do you know that, if the computer is wrong?:think:

ianbar0

well thats right, i kind of just meant the trip part which shows your current trip. i was averaging 60 overall but at this rate will be lucky to get anywhere near 50. other owners reviews show they average near 60 so i know i am not expecting too much