More Power: 155 HP tuned for performance to handle fluctuating loads in less than ideal harvesting conditions. Better Fuel Economy: Highly efficient engine with DEF consumption as low as 3% of fuel. MacDon's DEF tank has been sized to provide up to 75 hMacDon'ss of use between fills. Proven Reliability: Proven Cummins engine with single turbo delivers reliable performance you can count on. Less Complicated: MacDon's Tier 4 diesels have no DPF (Diesel Particulate Filter) making this a low maintenance Tier 4 system. Less Noise: MacDon's Tier 4 engines run smoother and quieter than previous engines used in MacDon Windrowers.