DeVille — C-body front-drive (1985–1993)

the standard HT-4100 (High Technology) V8, 135 hp; Wikipedia's High Technology engine article gives the option code LT8 to the HT-4100 and lists the DeVille among its applications for every year of this span, and its DeVille article calls the HT-4100 the standard engine of the 1985 sixth generation, continuing in 1986; the article's applications list ends the HT-4100 after 1987, and the 4.5L that replaced it for 1988 gives no code in any source read; both articles are Wikipedia, one source; decoderpo.com (T3, undated, no vehicle) reads LT8 as a 4.1L V8 engine, which agrees on the meaning only; the code is not listed in a Cadillac-specific factory page, so single-source

optional, 85 hp; Wikipedia's Oldsmobile diesel article lists the 1985 Cadillac de Ville among the front-drive LS2's applications (with the Buick Electra, Cadillac Fleetwood and Oldsmobile Ninety-Eight, which share the engine on the same platform), and its DeVille article says the diesel was optional for 1985 and dropped the following year; decoderpo.com's LS2 entry reads as a 6.0L V8, a different meaning, so it gives no support; single-source

200 hp; Wikipedia's High Technology engine article heads the 4.9 section with the code L26 and lists the DeVille among its applications for every year of this span, and its DeVille article introduces the 4.9L for 1991; decoderpo.com (T3, undated, no vehicle) reads L26 as a 4.9L V8 with multiport fuel injection, which agrees on the meaning only; both articles are Wikipedia, one source