well being that almost all preludes come with h22s in them allready. he or she didnt "swap" anything unless its an older one 88-90ish then he or she swapped it to an h22 which is a shitty car IMO. swapping a h22 in a civic of some sort would be much better being the prelude is HEAVY. oo and the h22 is a one of the bigger motors honda has so the gas mileage is not of the civics. just a little info for you.