the gas mileage is extremely minimal between 3.73 and 4.10's. it depends on what you want to do with the car. i wanted to prove a stock motor with bolt-ons and built aod car could go 12's. i dont know that i could have done it with 3.73's. but now i put a shot of gas on it and wish i had 3.73's cause im going to run out of motor on the gas, so i stepped up to 28" tires. no times on the gas yet.