22/28HP. 27/32HP, 30HP

This class was later renamed 27/32 H.P. from November 1934 and again renamed 30 H.P. from January 1937, although remaining similar in appearance. One difference was that some (perhaps all from the renaming to 27/32 onwards), including at least one survivor had the same bodywork design changes that had been applied to the 16 H.P. and its variants, i.e. tapering sides to the radiator base. The 22/28 H.P. were the first type to be fitted with one of the "JP" engines, JP standing for "Joint Product". These engines were built by Rustons at Lincoln but were designed in conjunction with R.A. Lister & Co Ltd. of Dursley, Gloucs., with whom Rustons had an agreement whereby they would not build small engines if Listers did not build large ones.