An STTDCi even in standard forum will be just as quick, if not quicker in most aspects of driving. I do like the ST170's but you are getting a much better car with the TDCi. It will also be a much nicer drive, with all the low down torque. Should pull effortless in every gear.

Just so you know mate, the color of the two is slightly different; the TDCi is perfomance blue and the ST170 is Imperial blue.

Benni.