From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Petrol consumption tests on a Phantom III vehicle.
| Identifier | ExFiles\Box 147\5\ scan0139 | |
| Date | 17th July 1937 | |
| CHATEAUROUX. Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux}8/JAB.17.7.37. 1249 also 300a To. Rm.{William Robotham - Chief Engineer} 32-EX. PHANTOM III. Petrol Consumption Further to your memo of the 14th, we have already gone into the possibility of the high pressure pump used with the larger needle valve seat, giving an over-rich mixture and increasing the petrol consumption. There has been no indication of richness at any speed, and the tests carried out show that the high pressure pump has not increased the consumption. They consisted of an out and back run of 334 miles. Night time was chosen so that no vapour troubles would confuse the issue, and maximum speed was used in order that the full effect of the fall in level with the low pressure pumps should be felt. Outward Run. Standard low pressure pump on dash working only. Standard .180 needle valve seat. 167 miles. Running time 2 hours 25 mins. Petrol used 26 gallons. Return Run. High pressure pump in frame working only. Standard .180 needle valve seat. 167 miles. Running time 2 hours 25 mins. Petrol used 26 gallons. We will carry out comparative consumption tests between direct and overdrive gears to-morrow. -------- Rm{William Robotham - Chief Engineer}/ IMW.{Ivan M. Waller - Head of Chateauroux} | ||