Engine variants

Hi, since I’m about to order an UP! my question. What really is the Utnerschied with the engines? are both the same size. only one 60hp and the other 75hp. With a friend that was at that time with a Civic only an air intake narrowing, taken out –> swups instead of the 75hp to the 90hp and saved 1500DM. So –> what’s mechanical/electronic different? Otherwise I’m still undecided –>complete or just the most necessary. Then give me Ford KA (98’i) n Payment and collect the change premium and thus come to almost 21% discount at the dealer. Can one at VW also possibly negotiate the first maintenances? Look forward me shcon to the answers.