140 miles later after a cruise down the M1 at 65mph

That MPG is accurate according to the fill to the brim vs miles calcs over the last month after I used the GAP IID tool to reset the CCF instrument pack for mpg offset from the stock +7% to zero. 2012 TDV8 Vogue (L322)

It was the first Range Rover to have a combined mpg of over 30, so that seems about right on a steady run…

 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

Another 10mph and it drops below 30mpg.65mph seems the sweet spot between not going too slow to be a problem on the M-Way and getting very good ( For a 4.4 V economy.
Also fitted another MAP sensor the other day so this may have done something.
BTW the speedo readout is adjusted as well for the taller 255/55 R20 tyres and it reads about 1 mph above the real speed on my GPS. 2012 TDV8 Vogue (L322)

Hi, I have the Same FFRR 2012 and I bought it with 255x55x20 on it (it came from germany).
at the controle technique (french MOT equivalent) they told me that the only acceptable mount for the vehicule were 255x50x20.

So I changed the lot ...

Can you enlighten me on the subject ?

Cheers
Sylvain "it needs some intelligence to undestand you may not have enough"

My 4.4 TDV8 is still struggling to get to 25mpg
Still working through the possible causes on that one…
Good to see it can be done  Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

255/55R20 we’re not OE size on the L322 so some countries insist on no deviation from spec. 2012 TDV8 Vogue (L322)

Ffrr-lover wrote:

My 4.4 TDV8 is still struggling to get to 25mpg
Still working through the possible causes on that one…
Good to see it can be done

Absolutely!
I’ve given the engine a few doses of cleaning agents via fuel additives and intake spray after manually cleaning the plenum and throttle body. I also cleaned the Maf sensor last weekend.
On Wednesday I’ll be taking her to Dartford Transmissions to replace a faulty thermostatic valve and that’ll be the first decent run since my cleaning work.
I’ll then see how her average mpg looks with a decent run… Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html