From top to bottom:
1. Base variant. 1 camshaft per bank (SOHC) for reduced cost, 4 valves per cylinder, regular intake with 1 throttle body per cylinder bank, short cast iron exhaust headers, and heavy flywheel for smoothness and greater lifespan. Runs on regular unleaded fuel (87 AKI/91RON)
2. Mid-grade. 2 camshafts per bank (DOHC) for less friction, performance intake, tubular headers, slightly lighter flywheel, and slightly increased rev limit. Runs on premium unleaded fuel (91AKI/95RON)
3. Top-grade for now. DOHC, individual throttle body per cylinder, lightest flywheel, long tubular headers, higher rev limit. Runs on premium unleaded.