Volkswagen Mark IV Forum banner


1050 Views 3 Replies 3 Participants Last post by  ChargedFury
Been recently having a few overboost issues with my TDI 140, found the issue to be a broken lug on one of the intercooler pipes so it had blown out of it's socket. All sorted.

I've not owned the car very long but I am quite disappointed by it's MPG, i travel 30 miles each way to and from work everyday and I have the choice of a nice scenic, windy A road or the boring M5 as my route.

With my old MKIV TDI 90 I was loving the 55-60 Average MPG, the MKV seems to be displaying an average of 37-43 MPG, one day I went to extremes and hardly touched the throttle to get 50 MPG (was falling asleep at this point though through sheer boredom)

Are there any pointers as to what can cause this dreadful fuel consumption for a Diesel? I'm fairly confident it's not my driving style (could be wrong)
1 - 4 of 4 Posts
I can definitely confirm that your TDi 140 should be running a lot more efficiently than 37-43 MPG: mine averages 54 over the long term (according to the onboard brain), which translates into 49 actual (calculated from fuel consumed and miles travelled).

As to the underlying cause, could be any of a wide variety of things (and possibly more than one): ECU, fuel system (pump or injectors), exhaust (including turbo), tyres under-inflated, and so on. Sorry not be able to give you anything more specific than that!
The only filter I haven't changed is the fuel filter because some fat thumbed mechanic has managed to round off one of the Torx screws, need to get my tap and dye set out and drill it out.
I will check all of the above, I'm going to take a wild guess right now and say it might be caused by my recent turbo issues.

Thanks all for the tips!
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.