They did various levels of tune in the 1.9 dCi engine on the L2 phase 1, ranging from 95bhp to 120. On an Authentique, it's probably one of the lower powered engines, especially if 0-60 is around 15 seconds.
Chip tuning is available and will give the performance a decent boost. Plug-in boxes can often be found on
for around the 200 quid mark (or even less second-hand) though I don't know how good they are. Expect the big names like Superchips to want to charge you around double that figure. Be aware that chip tuning voids any eligigibilty for an
failure, and with the 1.9 dCi's track record on this department, that's something that should be considered seriously. Some (like Superchips) will give you a warranty against their modification causing any damage, but I still wouldn't fancy playing 'piggy in the middle' between their insurers and
did go bang.
I'm not sure how the torque curve goes on the lower powered dCi's, but I know my 130 needs to be thrashed most of the way around the rev counter if you want to get the most from it. It runs out of steam before it hits the red-line (4750rpm) but it's certainly worth taking the needle to between 4000 and 4500 before changing up if you want the best acceleration.
Some people will tell you that this is rubbish, and you get all of your torque below 2500, but they forget to factor in the torque multiplication effect of using a lower gear. I've proven (while towing a ton of caravan up a steep hill) that I have considerably more torque at the wheels at 60 in 3rd than I do at the same speed in 4th. And of course it's torque at the wheels (not from the engine) that determines acceleration.