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).
Table comparing wheel and tyre weights in pounds for various car models and tyre sizes.
| Identifier | ExFiles\Box 123\3\ scan0203 | |
| Date | 19th March 1935 | |
| 19.3.35. Top Table: Wheel & Tyre weights - lbs. Model/Tyre Size, Weight (lbs.) Vulture 6.50 x 18, 64.25 Vulture 7 x 18, 73.25 SpectreCodename for Phantom III 7.50 x 17, 69.00 20/25 6.00 x 19, 64.0 Projected 20/25 6.00 x 17, 61.25 Bottom Table: Wheel & Tyre Weights - lbs. Model/Tyre Size, Weight (lbs.) Bentley 5.50 x 18, 50.62 Projected Bentley 6.25 x 16, 45 approx. Buick 6.25 x 16, 46.25 Graham 7 x 16, 53.375 Essex 6.25 x 16, 43.125. | ||