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 different radiator types detailing their chassis, weight, and water capacity.
| Identifier | Morton\M13.2\ img141 | |
| Date | 30th November 1931 guessed | |
| NEW LARGE HEXAGON TUBE MATRIX. Comparison of Radiators. Chassis Weight Water Capacity E.56327 Standard 3.750 long 97 lbs Round 2 gall.6½ pts. E.56692 19-GIV 3.250 " 98¼ lbs Round 3 galls. E.57135 20-GIV 3.250 " 86¼ lbs Hex.ended 2 gall.6¾ pts. E.57279 Capacity of engine & radiator 19-GIV 4 galls. 1½ pts. only 1 gall. 1f pts. | ||