To the OP... I'd stick with the Z4... I made the switch from more fun cars to a mile-eater diesel BMW a few years ago when I had to drive for work (many more miles than you).
For the pocket, it was worth it & to be fair... BMWs are a good balance of driver focus vs build quality with good fuel economy with their diesels... so it wasn't the worst step down from more fun cars.
But very soon after I got it, I missed the life from a petrol engine and have been longing for a decent 6+ cylinder for a long time.
The 6 cylinder diesels are noticeably better than the 4-pots... but they're no 3.0 Z4
I could only get about 48MPG out of a 116d so I don't see how someone can get 60 in a 320d.
I get 40-45 out of my Focus so it's not a driving style thing...
The 116d and 118d are horrible engines.
I once had a rental to drive to Poland and back (company paid)... it turned out to be a 2013 318d... it averaged 43-45mpg at the same speeds my own 2004 320d manages 50-55...
For motorways, the 318d and 316d are pathetic (unless you like trundling at lorry speeds, I suppose)... and despite being in Germany for a lot of the trip, I wasn't flooring it the whole way either... keeping a steady 80-85
For comparison, my 2004 320d averages 600 miles to a 12 gallon tank... on long runs keeping it between 70-75 then I'll get 700 to a tank and on back roads it still manages about 550.
I think 60 might be achievable if you have a very light foot, keep good distances to minimise wastage and keep the speed down to 60-65mph... but I haven't tried as I get bored too quickly and it hasn't been worth it... only tried 65mph in my XKR out of curiosity to see if I could break the 30mpg barrier and that didn't last long lol.
EDIT:
I wouldn't say doing 60 is trundling however I would happily have taken a photo of the computer to show my average. When I bought the car it was on 52.3 and when I sold it 60.1. I only reset the computer when I bought it.
However my point still stands, a newish well maintained 120d should have no problem getting over 50.
I would... 60 is trundling... but at least you're not going slower than the lorries.
People who think it's OK to go slower than a lorry should not be allowed on the road
I'm guessing you and the car spent most of your time together on the motorway to get that figure?
[TW]Fox;28365043 said:
Q to OP... why Super in the 2007 3.0?
It's way past Nikasil, so there's no benefit there to the cleaner fuel, I don't think it's got a knock sensor to adjust the timing dependent on RON and the 3.0 is not a highly strung or tuned engine, so I doubt you would see any benefit from 98+ over 95 other than your own peace of mind in thinking the fuel is that little bit purer.
Please do correct me if I'm mistaken...