Angela, the stock tires for the 20" rims are 33" tall. My 305's are just a hair under 34". But they are wider as well and so they needed to be on rims with a negative offset. Leveling the front allows more room for fitment on the front also. You can level it by cranking the torsion bolts but longer shocks in front will help the ride after leveling.

 

As said, any lift catches more air and reduces MPG. Larger tires weigh more and have more rotating mass to control and is equal to parasitic drag which adds to less MPG. You dont lift and add tires and expect good mileage. I know you arent expecting it but some people dont understand why it decreases.