My Sentra runs mid 30's. low 40's on the interstate. This is with normal driving too. Not like a grandma...Not like I'm auditioning for Fast and the Furious - Doomed to Fail.
How many miles on each car? I have a Sentra 01 with 120k on it now, still runs and feels tight like it is new.
I think someone posted a while back they were getting 11 with a hoe, which is what I would guess with the stock setup, with rims I would imagine it would be even worse.