Hi all.
I've had my 2007 TDV8 since November, and I'm a big fan overall. However, I've recently become concerned that the mpg is getting worse and worse. Around town (which is most of my driving) I get about 16-17mpg, and on a motorway at a steady 80 this weekend I got just 23mpg over 200 miles.

I remember when I drove the car home when I bought it I got just about 30mpg on the motorway (at about 70mph ish).

So, whilst I expect a lot of sarcastic comments about lead boots etc etc, does anyone have any ideas about what might be wrong?

I've done a search on here and intend to clean the MAF sensors. I'm assuming these will be in a similar position to in my p38?? - should I just be spraying with electrical contact cleaner??

Cheers in advance.

I don't know what's wrong with it but i do know thats its not right.
I had one and i drive with the lead boot and live on the side of a mountain and mine was 19.8 MPG.
There is probably and easy fix though.
Blocked EGR or something

Good luck  2020 Porsche Panamera Turbo Hybrid (V FAST)
2017 Range Rover Autobiography 5.0 V8
2018 JCW Mini Cooper
2018 Skoda VRS

First thing I'd check would be the two big turbo hoses at the top of the engine - check for splits, a common problem

Causes worse mpg, excessive smoke from the exhaust on hard acceleration and can make the engine feel rough

I would also get it booked in with a good garage ASAP - something is clearly not right and you risk more damage by continuing to drive it.... 2007 Zermatt Silver TDV8 Vogue SE - now sold but was a great car!

I had two things wrong with mine one has been mentioned the other hasn't.

I had a split Turbo boost hose and although I noticed the black smoke it didn't seem to have much of an effect on mpg. The other thing I had was a sticking rear brake caliper which easily knocked 10% off the mpg, dead easy to check as the affected wheel gets very hot, in my case too hot to touch, after 20 or 30 miles.

HTH
Geoff Geoff

Very good advice above

^^ Sticky rear caliper - I've had it on both I've owned . . .
I don't know about 10 %, but driving back from hols last year I lost 10mpg

 Where do you go after one of these . . . ?

I'm going on a longish drive this morning, so I'll check the wheel temps when I arrive and report back!

If your calliper is starting to seize, i would suggest not going on a long drive!

Take the car for a run of a couple of miles, check the temps and if not the issue happy days If it is the issue, i would seriously recommend you change your travel plans sir...

A, can cause big issues long distance. B, if it sticks on further 30mins after you leave, then you can wreck all of the mechanical components in that corner & C, it can be bloody dangerous sir!!!

I did check the wheels for 'hotness' after the school run this morning, so was pretty sure I was on safe ground going on a journey!

Anyway, I'm back now and all wheels were the same temperature to the touch - slightly warm - as normal. Also, all wheels are getting dirty at about the same rate, so I'm pretty confident it isn't a sticking caliper.

I'm planning a short session poking around under the bonnet this evening - is the MAF sensor in an obvious place?