You can't really compare these 2 cars on fuel consumption. Given if you buy the 2.0cc versions. Lets take some working examples.
For drivetrain on normal driving, the VTEC unit will be more fuel efficient than the VVT-i. Simple reason is more mechanical parts to turn in the RWD Altezza than in the FF Civic.
Still when both cars are running at maximum speed, i believe the VTEC would use more fuel. VTEC engagement is very aggresive. And when to get such power you use more fuel. Also EP3 has LSD. Which means few more gears to turn to move the car. Which in turn uses more fuel.
So fuel consiumption for EP3 is bad only when driven hard. Where the Altezza would be bad only when driven normally, and only when compared to drivetrain.
So like i said, you can't compare these 2 cars just on fuel consumption alone. You need to judge by price, usage, servicability and some more. If i want to buy a car just on the basis of fuel consumption alone, i would buy a new SAGA or Myvi.