Aspen 4 is alkylate petrol without oil - suitable for lawnmowers, rotary cultivators, snow blowers, boats and other 4-stroke engines. Ordinary... Give your 4-stroke engines the clean, high-performance fuel they deserve with ASPEN 4 Alkylate Petrol. Specially formulated to burn cleaner than standard petrol, Aspen 4 is free from ethanol and harmful additives, helping to extend engine life and improve reliability.