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).
Comparison table of ground clearances for various vehicle models.
| Identifier | ExFiles\Box 21\6\ Scan190 | |
| Date | 29th October 1934 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} C. to E.{Mr Elliott - Chief Engineer} x4217 Hs{Lord Ernest Hives - Chair}/FD.{Frank Dodd - Bodies}C/KH.29.10.34. Ground Clearance on 18-G-IV 25 HP. 4 Pass. 28-EX 40/50 5 Pass. 3-B-IV Bentley 4 Pass. 1-U-1 SpectreCodename for Phantom III 5 Pass. Essex 6 4 Pass. Cadillac 5 Pass. Under front axle, lowest point 10" D.W.S. Jacks 8.1" 8.625" 7.5" 8.75" 7.2" Under Crankcase 7.8" 8.5" 6.0" 7.3" 9.5" 9.5" Under Side steering tube 9.4" 8.1" 7.9" Stg. arm = 7.2" 9.0" 9.1" Under battery box 7.1" 8.4" 6.9" 7.0" 9.1" 9.3" Under rear cross member prop. shaft. lowest point 7.4" 7.25" 6.25" 6.5" - - Under front silencer 8.1" 8.2" 8.4" 6.6" 8.55" - Under rear silencer FP.{F. Potts}7.0" RP.7.3" FP.{F. Potts}7.8" RP.10.8" 6.5" FP.{F. Potts}6.5" RP.6.9" FP.{F. Potts}8.75" RP.8.85" FP.{F. Potts}10.15" RP.10.3" Buffer clearance - rear NS.{Norman Scott}3.075" OS.3.25" NS.{Norman Scott}4.4" OS.4.7" NS.{Norman Scott}2.25" OS.2.125" NS.{Norman Scott}3.1" OS.3.3" NS.{Norman Scott}3.9" OS.3.5" NS.{Norman Scott}2.8" OS.2.7" Hs{Lord Ernest Hives - Chair}/F.Dodd. | ||