Bizarrely High Mpg From My 2.1td Auto, What the *bleep*??!?

Last Tuesday, I topped up the XM 2.1 TD Auto.
Today, according to the odometer, I had driven 842 kilometers, which works out to 523 miles.

I topped it up today. When the filler shut off, I was in disbelief, so I persisted until the thing was all filled up, and in fact the diesel gushed out the filler hole. All I could squeeze in was 48.25 litres, which works out to 10,57 gallons.

This indicates that I got 49 (no typo... fourty nine) and a bit miles out of the gallon.

WHAT?

Conditions: approx. 60% motorway, the remainder A-road, B-road and local traffic. I know this because I have 'retraced my steps' to see if my odometer is fooling me... but no, it's accurate to a handful of miles (less than 20).

Driving style: while I would agree that I have nothing to prove at the traffic light I also enjoy the surge of force that I get when accelerating from 40 to 8-- er, sorry, that's 70, officâh. With the help of the cruise control, I do usually stick to the legal limit, although I do occasionally floor it a bit just to see what it is capable of.

We use this filler station on a regular basis (it's quite near to where we live), and it's always given us realistic figures, so we have reason to assume that this filler station doesn't give us more than it says.

In the light of the above, I would say that, for a 110BHP automatic, 49 miles to the gallon between tank stops is surprising to say the least. Mind you, it's not as if I am unhappy with this... but it seems to be out of line with what I read here.

What giveth??!?

Peter,

I have a 2.5td which is now in desperate need of a service. However, with fresh oil and filters, around town I usually get just over 30mpg and on a 300 mile run to Wales and back I averaged 45mpg. On the outward run to Wales I averaged 48!

Yes yours is an auto but it has a smaller engine and as I am sure most will agree that particular engine and box are ideally matched.

Just out of interest what mpg were you expecting?

Based on what I read in the MPG thread, I would have expected a 38 to 40 average... and as I said to the wife, I would've been hapy with 45.

49.5 on average (between tank stops) is definitely not what I expected.

Hi All,
On My Run up to yorkshire from Tilbury Motorway for most of the journey then the last 20 miles "A" and "B" roads up and down dale i regulary get 54 Mpg going up but comming back down 45 Mpg and that is at 60 Miles an hour on cruise control around town it drops to about 30-31Mpg


Norman

That is surprisingly good for an auto, my best recorded with the manual estate is a shade over 56 mpg although there was one particularly slow holiday where I think I could have got 1000 miles from a tankful but as I wasn't prepared to take the risk of running out, it wasn't documented.

Peter.N.

I don't think I'll find out what mine does around town... I hardly ever drive enough miles in-town only to get a reasonably accurate measurement (I don't have a trip computer, so my only clue is jotting down my mileage on my fillup bills).

That's one of the reasons I got a diesel... what with us living in the sticks, even our weekly shoppin trips are 15 miles.

my 2.5 is doing about 27 to 30 round town (darlington) with its new congestive bypass cum ? road charging eastern corridor????????? ,,, but on a run down the A1 with 3 accidents and lots of stop starts , pluss a run round yorks ring roat at 5pm i got ,41. sumthing to the gallon??, 257 miles on 27/28ish liters, please feel free to cottect my maths.

Hi Peterh.

No surprise to me -- they really are amazing machines. My 2.5 estate, with very mixed driving (although I don't drag race off the lights) averages around 41.5 according to the computer.

Mike.

That's where I go wrong...

Only a touch over 30mpg out of the last tank, but there have been some very frustrating drives to work over the past couple of weeks - I think someone must have left the madhouse door open round here or something.

My 2.1td auto exclusvie would return 52 MPG on a run (cruise engaged at 70). In fact the auto should be the same as the manual above about 50 ish as the TC locks up then (so no losses though it due to slipage), and the final drive is the same IIRC. Now its making horrible noise its dropped to such a leave the 2.3 litre 20v quattro on petrol is as cheap to run
Its been a LONG time scince Autos used sginfiactly more than their manual equivalents, anything relased on the marked post '85 ish is likely to have very similar consumption figures regarless of the number of pedals the car has.

Stewart

If I drive my 2.1 TD manual at 60, I get 55mpg+, so 49 in an auto doesn't seem too outrageous.

Likewise.

Hello all,
what a brilliant thread.When I had my 2.1 td auto I regularly used to get around 750 miles per tank full and that's around rural Lancashire with the odd run into Liverpool and back from Leyland,absolutely amazing from such a big car.
I remember cruising down the motorway at 70 and the revs showing around 2000.
amazing cars total luxury and small car economy,Fantastic.
Gary