Average mpg?
 

Hi all, having had my cdti auto for a few weeks now, I've managed to get a couple of tankfuls in, and using brim to be calculations, I've managed to get an average mpg of 34.87. This is on mostly shortish journeys of 17 miles each way to work and back, and round town stuff.
Is that about the average for a cdti auto, or should I be getting better?
Thanks

this time of year, with mostly local journeys in an auto it is in the range of what I'd call normal, I wouldn't worry.

Short journeys, cold engine, cold weather and a 2 ton automatic, it doesn't sound too bad.

I'm averaging about 43, but that includes a 130 mile round trip as well as some short journeys.

That's just about what I got from my diesel auto. You should see it increase by about 2mpg overall in the warmer weather.

I,v only had my 75 a few weeks
 

So I thought I would record the mpg before it had a service,,,I do a regular trip up the M11 and A1 from London to Lincolnshire,,I normally cruise about 60 on the mainroads but may boot it down the back roads ,Anyway I got 43mpg.I was abit disapointed I was expecting somewhere around 50ish..Oh yeah my car is an 01 diesel auto tourer,,so not too light ..Perhaps with new filters it may improve...regards all

Dunno if this helps, find ya car and click 'more info'
http://www.parkers.co.uk/cars/review...5/saloon-1999/

the key thing is not to be deterred by a meaningless average on a trip computer.

The average mpg data is utterly meaningless across journeys of different types to me.

For example, do a long motorway journey, and you want to know how good your mpg was. So zero it on the trip and you will have a meaningful figure at the end. Keep driving after all local miles at the end of the journey and look at it across the whole tank after that, and it is skewed by the massive reduction in mpg when you come off the motorway, and statistically becomes a bad average for my purposes. So really it is down to how meaningful you want the figure to be to you, because unless the time between resetting the average calculation .

Or in less words - auto's get bad fuel consumption on local miles, but better on motorways when they have been able to go into lockup mode inside the box. Shocker eh?

If you don't ever zero it and leave it running for weeks and weeks across a wide variety of journey types - personally I don't find it a particularly useful piece of information then. If your journeys are mostly similar, it will have more meaning to you perhaps. YMMV I believe is the modern vernacular.

That's just me though.

It's what my auto does pretty much, if you reset the mpg thing on a motorway at about 80mph it will sit at 47mpg for as long as you are doing that speed but otherwise yeah, about 34-36mpg average. Someone will be along shortly to tell you that their auto CTDi does 60mpg on a bad day but hey ho :}

My derv-ish estate gets 100 miles / division, which works out at around 9 miles to the litre. Why have we persisted in MPG calculations when the gallon is now just a throwback calculation and open to confusion with the US version?

Because we are all familiar with mpg, and are no more likely to confuse our gallon with the American gallon than we are our mile with the Swedish mile. ;) :D