Get yours mapped and you'll be running the same sort of torque if not more plus a lot more bhp. I owned a 118d (143bhp) previously before purchasing my 1.8tfsi and mpg wise I averaged 38-42 around town, went down to the teens when giving it some, but on a long journey 60mpg is achievable with sitting at 70mpg. My 1.8 does 35-37 around town and can do 55mpg on a run, so they aren't that great on fuel. For people that think from a standing start you would beat him easily, their wrong, I could easily achieve 0-60 times around 8.5secs in my 118d, therefore a 120d with 177bhp would easily be able to achieve 0-60 in around 7-7.5 secs. In the wet it is a completely different story. The BMW diesels are great engines, but I hope your friend has either BMW warranty or deep pockets because the 2.0 Diesel engine has a very poorly designed crank and costs around 5k upwards to repair and with BMW not been prepared to pay out, it's very costly. This is such a massive issue thousands have had the problem and it was even on watch dog, this is one of the reasons I sold mine and the fact winter is coming but they do drive better than an A3.
I had an A5 3.0tdi mapped to 310bhp and it felt slow compared to a std S3. Fuel economy wasn't much better either! Admittedly, the big BMW diesel engines are a lot better than Audis but petrol all the way for me!
All depends on how far up the rev range u are with diesels.
Classic example is on an overtaking lane on a A class road.Mr I'm going to overtake slowly and ur following in 4th gear by the time they have pulled in ur at 4000 rpm. The car doesn't seem to pull fast and it doesn't seem logical to go into 5th yet but you should