dmjw01 said:
So why did you buy a diesel then?
You quote a set of journey conditions which will make a diesel the least efficient that it can be, and yet still it beats the petrol by a moderate margin. I would never recommend a diesel purely on the strength of its mpg, particularly to someone who does short journeys - by their nature they take longer to reach optimum temperature.
I didnt buy it just because it was a diesel. I happenned to like the look of it, and that was the main reason. The fact it would seem to be economical was a very nice bonus. And it is.... just not as much as I'd been led to believe.
Again, you really should have got more than 54. The other day on a decent motorway run, with occasional blasts up to (ahem...) mph, mine gave me over 58, and it's not properly run-in yet. Once it's fully loosened up I expect it to be better still.
54 is not too bad considering the official combined figure is 52.
Diesels take a lot longer to break in. For that reason I would also not recommend a diesel unless you intend to keep it for a good few years, otherwise you'll never see its best performance and economy.
I did 20,000 miles in mine. Despite the fact that according to some, it was not ran in, I really could not see it becoming THAT much better than it had already become.
In fairness, there always seems to be a big variation in the fuel economy figures given by people with these cars. It would seem that if your car is tucked away in a nice garage, and then used for 20+ mile motorway jaunts, then you'll get excellent economy. However, for those of us who scrape ice off our cars in the winter, the car takes longer to warm up, and if they then, like me, drive into town, then they arent going to see much better than a petrol.
I was led to believe that diesels would always trounce petrol for economy in a like for like comparison (as in, in roughly equivalent performance cars, and the same journeys). I did believe these claims due to my inexperience with the characteristics of diesel cars. Knowing what I now know, I would not have bought the diesel, but I am not putting it down, but people need to be aware that they are completely different, and that pottering 5 miles to town and back is not going to do them any favours.