Fuel Economy of the 2024 BMW Alpina B8 Gran Coupe. Compare the gas mileage and greenhouse gas emissions of the 2024 BMW Alpina B8 Gran Coupe side-by-side with other front-engine, rear/all-wheel-drive, 4-passenger, 2-door coupe. PRICE AS TESTED $175,745 (base price: $147,995) four doors, and an acceleration force so strong, you'd think the 2024 BMW M8 Gran That isn’t much more than the BMW M8 Gran Coupe but the B8 has a higher top speed and it feels infinitely more long-legged than any M car. In this new video, we see a POV drive of the ALPINA B8 9lUVxt.