Member Since: 16 Jan 2019
Location: Hampshire
Posts: 3
Dscovery 4 TDV6 fuel economy
The fuel economy on my 2010 Disco 4 TDV6 has suddenly worsened. It has dropped by 5-6mpg for no apparent reason.
The car was connected to diagnostics and no fault codes appeared and the air filter and fuel filter were only changed 3k miles ago.
I did remove the air cleaner to inspect it and it was fine. There were some feathers present in the air filter box. Can the inlet become blocked.
Also, the noise of the engine on tickover has changed to a deeper note - similar to an old carb engine being rich.
Any ideas?
16th Jan 2019 10:32 am
plocker
Member Since: 14 Mar 2016
Location: Preston
Posts: 828
Wearing torque converter? How many miles has the box done?05 V8 HSE Bonatti Grey
16th Jan 2019 10:35 am
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 73086
Check carefully for binding brake calipers, could easily explain the drop in mpg.
Plus don’t assume you haven’t got 2 problems. Could be binding brakes and suicidal chucks in the air box.
Last edited by DSL on 16th Jan 2019 10:37 am. Edited 1 time in total
16th Jan 2019 10:36 am
Davethegeo
Member Since: 01 Oct 2015
Location: Edinburgh
Posts: 913
That happens every winter to me. It will improve again when the weather warms up.D1 300Tdi - gone
D2 Td5 ES (Alive remapped...mmm) - sadly gone
D4 2012 SDV6 XS - Stolen
D4 2014 SDV6 HSE - Shiny
16th Jan 2019 10:36 am
Gareth Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26775
Whats the total mileage?
Post a video of it idling to Youtube and link it to here so we can hear?
16th Jan 2019 10:37 am
Tylney15
Member Since: 16 Jan 2019
Location: Hampshire
Posts: 3
I've had the car since new.
It has done 44,000 miles only
16th Jan 2019 10:46 am
latnutgub
Member Since: 25 Aug 2011
Location: Huddersfield
Posts: 170
I may be teaching you to suck eggs, in which case I apologise.
How are you calculating the MPG. The figure calculated by the car is notoriously unreliable & optimistic.
Probably the best method is to top-up the tank every time you refill, and calculate "from full to full". This still does not allow for the speedometer/trip "error", which you can check for your car & tyres with a decent GPS.
NJSSAm I Gammon or Woke ? - I neither know nor care.
2016 Discovery 4 Landmark
2011 Mercedes Benz SL350 (R230)
1973 MG B GT V8 - 3.9L John Eales engine, 5 speed R380 gearbox, since 1975.
1959 MGA roadster - 1.9L Peter Burgess Engine - 5 speed gearbox
Past LRs - Multiple FFRs, Discos & a Series I - some petrol, some diesel,
none Electric or H2 fuel cell - yet.
There are 10 types of people in this world: Those who understand binary, and those who don’t.
16th Jan 2019 11:03 am
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 73086
20+% is still a pretty big drop, assuming no change in measure of mpg. I usually saw ~10% drop in winter when everything was working OK.
16th Jan 2019 11:11 am
dgardel
Member Since: 03 Nov 2009
Location: Greater Venice
Posts: 2025
Davethegeo wrote:
That happens every winter to me. It will improve again when the weather warms up.
This is the case for all cars to which it is fitted.
If you are "pre-heating" the car once or twice a day then this can be significant as I have found out. It's difficult to calculate quite how much, but I have hear that it is of the order of 0.6 litres of diesel per hour - say 0.1L per 10 minutes.
If you are not doing many miles per day, but pre-heating twice this adds up.
NJSSAm I Gammon or Woke ? - I neither know nor care.
2016 Discovery 4 Landmark
2011 Mercedes Benz SL350 (R230)
1973 MG B GT V8 - 3.9L John Eales engine, 5 speed R380 gearbox, since 1975.
1959 MGA roadster - 1.9L Peter Burgess Engine - 5 speed gearbox
Past LRs - Multiple FFRs, Discos & a Series I - some petrol, some diesel,
none Electric or H2 fuel cell - yet.
There are 10 types of people in this world: Those who understand binary, and those who don’t.
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum