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).
Weight of the Phantom III model and its impact on cost and performance.
| Identifier | ExFiles\Box 124\3\ scan0406 | |
| Date | 26th August 1936 | |
| To Sg.{Arthur F. Sidgreaves - MD} & Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}4/KW.26.8.36. Phantom III Weights. We have now got the average weight of the first Phantom III's delivered to customers, and compared them with the weight of the last Phantom II's sold twelve months ago. The figures are tabulated in the attached sheet. It will be observed that the Ph.III chassis is about 45 lbs. lighter than the last of the Ph.II's, and yet the completed cars are about 1 cwt. heavier. We think that this is a depressing start for a new model. We know from experience that the weight of our chassis in production goes up about 10% every five series, as shown from the tabulated list of 25/30's and Ph.II's. The Bentley is an exception because we have concentrated on preventing the usual thing happening. The reason we are continually stressing the weight question is as follows. (1) Cost. Contrary to the general impression we find that on balance when we save weight we save money. We attach a summary of recent Bentley Standardisation Sheets from which it will be seen that in reducing the chassis weight by 122 lbs. we have saved £13. 4. 2d., but in adding 71 lbs. we have done so at a cost of £14. 15. 11d. We believe the Ph.III chassis is too heavy, and that if we save weight we shall reduce costs. The Bentley and 20/25 have almost exactly the same number of pieces but the Bentley is lighter and less costly to produce. (2) Performance. Our original Ph.III which weighed 50 cwts. had the same acceleration as a 4¼ litre Bentley. At 53 cwts. it is 6% down on the Bentley already. A customer ten days ago demonstrated that he could out-perform the Bentley with his V-8 Cadillac. Several other American cars are in the same class, simply because, fitted with Saloon bodies complete, they weigh under 4,000 lbs., or less than the Ph.III chassis alone. It is difficult to understand how one can justify a tax of over £50 per annum and a petrol consumption of under 10 M.P.G. if superlative performance is not at least one | ||