I fitted one of the Broquet units some years ago to my WW2 GMC truck as the engine was designed for leaded fuel, the extra heat of unleaded fuel had in the past caused the stretching of the exhaust valves. The claim by Broquet that cooler running and the capability of using unleaded in place of leaded fitted the requirement due to the unavailability anymore of leaded. After fitting one the running temp was definitely lower, IIRC before trundling on the flat on a coolish day was 210*F and after when climbing Marine Drive at full throttle in 4th around the Great Orme on a hot day was 200*F.