Usually you will find the difference between the two escorts are that the 1.6 finesse will more than likely be a 5 door and the gti will more than likely be a 3 door. I have a 1.6 si 5 door myself and when i checked the difference between that and the GTI there was quite a difference in price as they class a 5 door car more as a family car even though its a sporty engine. As with the petrol the 1.8 Gti will swallow a bit more than the 1.6 but the 1.6 can swallow it when your foot is put down anyway!