The development of special fuel was attributed to the work of "Rod" Banks, an engineer who specialised in fuels and engine development. After using neat benzole for early ground test runs; a mixture of 11% aviation petrol and 89% benzole, plus 5 cubic centimetres (cc) of tetra-ethyl lead per Imperial gallon (4.5 L) was tried. This blend of fuel was used to win the 1929 Schneider Trophy race, and continued to be used until June 1931. It was discovered that adding 10% methanol to this mixture resulted in a 20 hp (15 kW) increase, with the further advantage of reduced fuel weight – particularly important for aircraft use – due to its lowered specific gravity. For the 1931 airspeed record attempt acetone was added to prevent intermittent misfiring, the composition of this final blend was 30% benzole, 60% methanol, and 10% acetone, plus 4.2 cc of tetra-ethyl lead per gallon.