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Rhodium is an important component of three-way catalysts for emissions control on gasoline engines1. It has unparalleled activity in NOx reduction under stoichiometric conditions, where very high conversion efficiencies are required to meet current and future legislative targets. Over 90% of world rhodium usage is in such catalysts, and in recent times the price of rhodium has increased enormously2. This has lead to significant focus on reducing the quantity of rhodium required whilst still retaining the ability to meet the most stringent emissions legislation. Experiments are described where three-way catalysts employing advanced washcoat formulations and coating techniques are evaluated with a range of rhodium levels right down to 1g/ft3 which nevertheless still meet Euro 4 emissions limits after 100,000 km-equivalent bench engine ageing.