§ Mr. Hooleyasked the Minister of Transport what calculations have been 149W made by his Department of lengthening car engine life by the use of lead-free petrol, which arises from omitting corrosive material now included in the lead additive, for example, ethylene dibromide.
§ Mr. Kenneth ClarkeNo precise calculations have been made, but the report of the working party on lead in petrol, published by the Department in July of this year, concluded that use of lead-free petrol in vehicles currently on the roads in this country would in most cases create major problems of engine durability due to valve seat recession. Assuming design of new engines for use of lead-free petrol a slight reduction in corrosion could be expected due to the absence of alkyl halides, but some increase in cylinder and piston ring wear would also result.