Motor Doctor is a motor oil additive specifically for diesel engines past their prime — think of compact tractors with thousands of operating hours, weak oil pressure, and creeping oil consumption. The additive stabilizes oil viscosity, restores oil pressure, and keeps the oil film intact on critical areas such as pistons, valves, and main bearings.
A Kubota or Iseki with 5,000+ operating hours often starts showing symptoms: a bluish puff of smoke during cold starts, oil running out faster than before, and slightly less power under load. These are all consequences of wear in the piston/cylinder assembly. An overhaul quickly costs thousands of euros; Motor Doctor is a fraction of that price and can postpone that overhaul for years — especially if the tractor is otherwise still performing well.
✔️ Stabilizes oil pressure in engines with high operating hours
✔️ Reduces oil consumption and blue smoke during cold starts
✔️ Protects pistons, valves, and bearings against further wear
✔️ Works with all oil types (mineral, semi-synthetic, synthetic)
Suitable for compact tractors from: Kubota, Yanmar, Iseki, Hinomoto, Mitsubishi, Shibaura, Satoh, Honda, and all other compact diesel engines.
Tip: combine with a fresh oil change and oil filter for the best result. The effect lasts until you change the oil again — then add another bottle of Motor Doctor.
See below which machines this product is suitable for.