Currently getting 10-12Km/l (1.0L 1KR-FE), never took it on a highway so don't know about the mileage I'd get there. I need to replace the fuel filter as soon as possible. Current mileage on my Belta is 34,000Kms. Bought it on 18,000Kms have driven it 16,000Kms since 2007 
Yes indeed G selections are expensive, especially in the Punjab region. They are high in demand and not available at the same time.