If you REALLY want to know the true MPG you'll need to do a few full tank to full tank calculations and ignore the computer, however you might wish you hadn't, expect to be disappointed, I'm sure you will not like what you find. As long as your brakes aren't binding and it's well serviced it will be using the same amount of fuel as every other 3.6 TDV8 over the course of a full tank regardless of what the computers might say.

JayGee wrote:

MPG watching only serves the purpose of being a warning sign if something was wrong. If you want good mpg buy another car

My averages over the last few years, tank full to tank full, 2020 (22.45), 2021 (24.86), 2022 (25.77), a real mix of small country lanes, A roads, Motorway and about a quarter of the time with a trailer, best 32.27, worst 16.79 mpg, per full tank, not on the vehicle fuel average. Not too bad, only drive about 7000 miles per year and far more comfortable than a pickup.
I don't often hammer it and 70ish on the Motorway.

Usually 22-25 across a tank for my 2010 3.6 TDV8 with normal diesel.

I'm fanatical about resetting the trip when I fill up and on a long run, eg Cheshire to Kent, I've never broken 30.

Interestingly, by my calculations I see better MPG when I fill up with 'super' diesel to the point where it's great than the cost difference of the fancy fuel. Did'nt expect that I must say

Really, I had often thought of the more expensive stuff being a bit snake oil. Do you think you see the greater mpg from super in long runs or shorter trips? V8 or else ...

The main difference with the premium fuel is the additives like Red x which help keep the engine clean and running slightly more economical. I rarely use anything other than premium fuel to help the longevity of the engine and the egr valves. When I do mix with non premium diesel (I never go to super market stations after water issues in fuel tanks) I notice I do get less mileage.

Out of interest I thought I would look at the owners manual to see what it said about MPG. Its predictions are close to what I would expect (from the onboard computer). Found it odd that it thinks between 2-3k revs is its most efficient range for the engine…

Click image to enlarge

Click image to enlarge

Click image to enlarge

I had a 3.6 for 4 years, a 2010 facelift model. Consistently did 500-520 miles on a full tank, mix of long runs and short hops. Always gave more miles on Shell V Power/BP Ultimate.

The extra mpg gains of premium fuel never make up for the cost difference - if they did everyone would be using it  2012 TDV8 Vogue (L322)

After owning my car for a while now the one thing that stands out when it comes to fuel economy is on a longer run the difference between driving at 70-75mph at around 1900-2000 rpm verses 60-65mph at around 1600 rpm is bigger than expected.

A month apart in similar weather on the same 65mile trip, with the same brand fuel and amount in the tank I got 29mpg doing 70-75 most of the way, but got 33.7mpg when doing 60-65 the second time around.

Slightly amazed that 5-10mph can make such a difference, doubt that’s the case in my other cars.

I have a Bodsy remap that was done with a mix of power and economy in mind. Doing my maths the on-board computer is not far off, in fact it maybe under estimating the mpg based on some rough calculations (need to do a few more full to full tanks to confirm). Bodsy did say that some on-boards over estimate and some under estimate, who knows why that is the case. 2009 pre-facelift 3.6 TDV8.

Just crossed the 20k miles ownership, 20030 to be precise, 3.6TDV8, the best I have managed is 34.1 mpg, the worst 17.1, a lot of low speed driving, quite often with a cattle trailer behind.
The average overall is 23.92 mpg, is that bad, I don't think so, before the FF we had an Isuzu Dmax for 36k miles, that averaged 26.5mpg, similar sort of driving, the Defender we had before that was 25 or so mpg long term
I'll stick with the FF if you don't mind.

I did the same 65 mile journey today as I did a while ago (see my old post above) and got 34.8mpg according to the trip computer.

I think this is the max possible on this journey as it was a warm day and there was no traffic - and I didn’t go over 2000rpm, guessing the average was 1700.

These cars are not made or bought for their high mpg I know, but I do find it quite satisfying when I get more than expected. No idea if the Bodsy remap and the Millers additive I add to standard Esso diesel has anything to do with it, guessing a small amount.

Most importantly it was one of those smooth, quiet, floaty, effortless drives that when I got out I thought - what a bloody great car this is. 2009 pre-facelift 3.6 TDV8.

I managed 36.4 according to the dashboard on Sunday over a 230 mile round trip at manly 60/65 mph with my 3.6 tdv8.

<70mph is the key to better mpg. The L322 has the aerodynamics of a brick and the fuel needed to push this through the air rises disproportionatley the faster you go. 2012 TDV8 Vogue (L322)

I have just done 1661 miles in my 3.6 in just over a week going up to the Highlands of Scotland 3 tanks of fuel still got 128 miles left out of the last tank and I used standard diesel from Costco, BP and Esso.
609 miles out of the first tank average 32 from Costco
601 BP just less than 31 point something
And 480 so far with Esso with 128 left.
I think I could get 700 miles out of a tank if I wanted to run it on fumes.
My 4.4 Tdv8 got nowhere near those figures.

Click image to enlarge

Click image to enlarge

Click image to enlarge

Click image to enlarge