My friend just installed a chip into his '01 S4 and I got this chance to test drive it last week. The car was A LOT quicker than stock and the whole car sounded very different than before too. A stock S4 has very quick 1st and 2nd gear, but after 3rd, the car seems going nowhere. However, after putting on the chip, the S4 went all the way up to 180km so quickly and smoothly and one thing to keep in mind is there were 4 people in the car! Definitely one amazing mechine.