Member Since: 21 Sep 2007
Location: Aberdeenshire
Posts: 1391
Just filled up today, actual since last brim up was 22.5 mpg, computer shows 27.7
Not too bad considering the cold temperatures and shortish journeys over the last two weeks but why the difference in the figures? Pretty pointless having this feature if it is so inaccurate.
Still great to drive every day and no problems to report whatsoever after nearly 4 months - touch wood.
Dex
16th Jan 2008 12:24 pm
wolster
Member Since: 07 Dec 2007
Location: various
Posts: 352
A test!
(I've not done this by the way. It just occoured to me the other day)
On a stretch of flattish motorway which doesn't climb or drop in overall altitude. Set cruise to 75 mph then reset trip computer. If its quiet enough, hopefully you can maintain this state of tranquility for 2 miles. Check your mpg and post it here.
Lets see what variations we get. I'm guessing results will vary. Debate will then rage as to whether we have differences in engine efficiency or trip computer accuracy.What if the "Hokey Cokey" really is what it's all about?
'54 TDV6 Auto SE, Silver, Leather, HSE Wheels, Alpine Roof, Light Guards, Black Side Tubes, Tints.
Y 110 County Commercial, White, just bought it... watch this space for added bits!
16th Jan 2008 2:05 pm
ThatMartinChap
Member Since: 06 Nov 2007
Location: Deepest Darkest Berkshire
Posts: 696
good idea - i bet its way off.
16th Jan 2008 2:33 pm
simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
If I can cover between 460 and 500 miles on a tank then I'm happy. That could be 27MPG or 30MPG - who cares. Its a great range and the average I get day to day in my 3 year old.
16th Jan 2008 2:41 pm
Pricey
Member Since: 10 Jul 2007
Location: Swansea
Posts: 40
MPG
I dont thrash it and try and avoid busy or congested areas and can only average 21.9mpg.Range ffrom full is 368miles.Does not change when towing a twin axle tin tent.Something must be wrong.11000 miles on clock on a 56 plate.HELP
16th Jan 2008 8:46 pm
simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
I dont trash around either, but also dont hang about when I'm in the mood.
I dont thrash it and try and avoid busy or congested areas and can only average 21.9mpg.Range ffrom full is 368miles.Does not change when towing a twin axle tin tent.Something must be wrong.11000 miles on clock on a 56 plate.HELP
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
Zero your trip (the one below the odo) at the next bank loan inducing fill up and see what it gets too when the orange light comes on to tell you your next loan payment is due... then add that to the range left. Oh and zero your MPG / Trip thingy too.
16th Jan 2008 9:42 pm
Shiny Silver
Member Since: 27 Feb 2007
Location: Cambs
Posts: 170
I changed jobs at the start of the New Year.
2007 was approx 22MPG for 15 miles per day average speed less than 20MPH, now 2008 it's 29 to 30 for 110 miles per day at average speed of minimum 48MPH.
And going to work in morning is consistantly 1MPG less than coming home in the early evening, (it must be an uphill struggle!)
I get more MPG by using the A5 in the evening than I do on the faster and quicker M6 Toll which runs parallel to it. my 25 mile journey, 18 on the A5, during which I am doing a max of 50mph, but with a lot of stopping and slow traffic. The toll I am only going at 70mph no faster.
overall at the moment I am getting around 28-30 mpg average per tank full
"I know that you believe that you understood what you think I said, but I am not sure you realize that what you read is not what I meant"
16th Jan 2008 11:17 pm
Wex
Member Since: 16 Apr 2007
Location: Knackeragua
Posts: 5173
Wouldn't it be nice .....................
17th Jan 2008 1:16 pm
simonsi
Member Since: 14 Oct 2007
Location: Auckland
Posts: 1264
OK, anyone any ideas on this one:
I find the calculated fuel consumption matches the fuel computer within 1mpg fairly consistently.
I primarily use Tesco diesel from the Loughborough store. Occasionally I run down to the South Coast and fill for the return at the Tesco store nr Hamble. Longer gaps between this round trip would mean that the tank is effectively all Loughborough fuel at the start of the trip down and is approx 50:50 Loughborough/Hamble when starting the return trip.
On the run down I get 26.5mpg, on the run back I get 28.8mpg
This difference seems consistant irrespective of weather conditions over several round trips, no load difference between the trip down and back.
...AND it also occurred on my previous D2!!!
So I deduce it just has to be a difference between the fuel supplied from each store.
As the journey always starts from Loughborough there may be a cold start / transmission warm-up issue for the downward journey that is largely not there for the return but I can't see that having such an effect over such a long distance (and the engine doesn't seem to have any other running issue, the vehicle is in very good order as was the D2).
My current theory is that the Hamble store gets its fuel direct from Fawley at Southampton, possibly Tesco buy a "better" grade as the costs of delivery from Fawley are so low it makes sense to take a better-than-they-would fuel. The Loughborough store would have longer delivery distance so they may have opted for the cheapest possible fuel to offset the cost of supply.
Anyone any thoughts??? Cheers
Simon
17th Jan 2008 1:41 pm
Wex
Member Since: 16 Apr 2007
Location: Knackeragua
Posts: 5173
Is it downhill from A to B and uphill from B to A ?
17th Jan 2008 1:44 pm
simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
Is it that important
As Wex says, there may be more uphill on the way back and also you may be keener speed wise as your on your way home
17th Jan 2008 1:54 pm
simonsi
Member Since: 14 Oct 2007
Location: Auckland
Posts: 1264
simon wrote:
As Wex says, there may be more uphill on the way back and also you may be keener speed wise as your on your way home
Maybe but I wouldn't think that is the only long journey I do where I am keener to get home than to go in the first place so I would see similar differences in consumption elsewhere.
The uphill bit may have merit (Hamble must be closer to sea level than Leicestershire) but only by a 100m max - could that account for the energy 3mpg over 150 miles equates to
Edit - NO!! the lower mpg figure is on the way uphill so it can't be that - in fact the effect is greater if you take that into account..... Cheers
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