Theoretically the Pre98 SHOULD be faster... the 98 Zetec has a VCT solonoid... which basically does nothing (I know it doesnt, but it doesnt really do what it was designed to do). Anyways, I would say the reason that the 98 seemes faster is because its overall a newer and better car... The trannie is younger in it... the engine probably isnt as dirty therefore more efficent... Id say when you get the 96 all cleaned up and running in top shape again.. it will very likely beat the 98...
