Oldsmobile Firenza — J-body (1982–1988)

The Firenza was Oldsmobile's front-drive J-body compact for the 1982–1988 model years, sold as a sedan, a hatchback (to 1987), a Cruiser wagon from 1983 and a coupe from 1986 (Wikipedia). The NICB VIN manuals list the Firenza and Firenza Brougham in 1982 and, in the 1988 manual, the Firenza with Firenza Brougham, LC, LX and GT. No GM order guide, data book, Heritage kit or service RPO list for the Firenza is in the archive, so only powertrain codes are listed: Wikipedia's Firenza article names and dates the engine codes, and the Heritage kits of the Chevrolet Cavalier, the J-body twin, are cited for the shared V6 (LB6), for LL8 in 1988 and for the transmission codes MM5 and MX1, which the kits never tie to the Firenza; they only date a code the two cars share. No source read ties an option, package, paint or trim code to the Firenza with a year, so none is listed.

Codes

Engines

Code	Description	Years	Models/Notes	Confidence
L46	1.8 L (112 cu in) L4, OHV, carburetor	1982	the launch engine; Wikipedia's Firenza article (infobox and Engines list) and its 122 engine article give it to the Firenza for 1982 only; the carburetor is a 2-barrel in the merged Skyhawk and Cavalier docs, which Wikipedia's Firenza article does not say	single-source
LH8	1.8 L L4, SOHC, throttle-body fuel injection	1982–1986	the Brazilian-built overhead-cam four, added during the 1982 model year; Wikipedia's Firenza article (infobox and Engines list) and its Family II engine article give it to the Firenza 1982–1986	single-source
LQ5	2.0 L (121 cu in) L4, OHV, throttle-body fuel injection	1983–1986	the OHV engine enlarged to 2 liters for 1983; Wikipedia's Firenza article (infobox and Engines list) and its 122 engine article give it to the Firenza 1983–1986	single-source
LT2	2.0 L (121 cu in) L4, SOHC, throttle-body fuel injection	1987	Wikipedia's Firenza Engines list and its Family II engine article give it 1987–1988, but the article's text says the overhead-cam engine was dropped for 1988, so only 1987, which both print, is claimed	single-source
LL8	2.0 L (121 cu in) L4, OHV, throttle-body fuel injection	1987–1988	replaced the LQ5; Wikipedia's Firenza article (infobox, Engines list and the 1988 text, which leaves only the OHV four) and its 122 engine article give it 1987–1988; shared J-body code; the 1988 Chevrolet Cavalier kit prints LL8 on a single-condition air conditioning line, a sibling page dated 1988 ⛭ GM Heritage — 1988 Chevrolet Cavalier, p.42	single-source
LB6	2.8 L (173 cu in) V6, OHV, multiport fuel injection	1985–1987	an option with the GT package from 1985 (Wikipedia); Wikipedia's Firenza article (infobox, text and Engines list) gives it 1985–1987 and says the V6 was dropped for 1988, so 1988 is left out although the 1988 Cavalier kit prints LB6; shared J-body code; cited from the Chevrolet Cavalier kit, whose optional equipment weight pages list it in each year (a V6 optional or standard on some Cavalier lines) ⛭ GM Heritage — 1985 Chevrolet Cavalier, p.35 ⛭ GM Heritage — 1986 Chevrolet Cavalier, p.37 ⛭ GM Heritage — 1987 Chevrolet Cavalier, p.37	single-source

Transmissions

Code	Description	Years	Models/Notes	Confidence
MM5	Transmission, 5 speed manual (merchandised order code)	1984–1987	matched to the unit by meaning: Wikipedia's Firenza article names a Getrag 282 five-speed in its infobox and five-speed GT cars for 1984 and 1987 but prints no code; the kit's 1985 line reads "with the L4 engine only"; 1988 is left out because no listed kit page heads the code; shared J-body code; cited from the Chevrolet Cavalier kit ⛭ GM Heritage — 1984 Chevrolet Cavalier, p.11 ⛭ GM Heritage — 1985 Chevrolet Cavalier, p.35 ⛭ GM Heritage — 1986 Chevrolet Cavalier, p.37 ⛭ GM Heritage — 1987 Chevrolet Cavalier, p.37	single-source
MX1	Automatic transmission, 3 speed (merchandising code for the THM 125C)	1984, 1986–1987	matched to the unit by meaning: Wikipedia's Firenza article names the 3 speed Turbo-Hydramatic 125 C automatic in its infobox but prints no code; the 1986 page prints MXI (letter I); 1985 is left out because the kit's option line is cut off after MX, and 1988 because no listed kit page heads the code; shared J-body code; cited from the Chevrolet Cavalier kit ⛭ GM Heritage — 1984 Chevrolet Cavalier, p.11 ⛭ GM Heritage — 1986 Chevrolet Cavalier, p.37 ⛭ GM Heritage — 1987 Chevrolet Cavalier, p.37	single-source

Sources

Factory documents (T1)

No Oldsmobile factory document for the 1982–1988 Firenza is in docs/factory-docs/ or docs/heritage-ocr/. The rows cite the Chevrolet Cavalier Heritage kits (J-body twin) for shared engine and transmission codes only, on the brief's listed RPO pages (owner, 2026-10-03):

[HK] chevrolet/1984-Chevrolet-Cavalier.txt — MVMA specifications, model year 1984, optional equipment weights (p. 11)
[HK] chevrolet/1985-Chevrolet-Cavalier.txt — MVMA specifications, model year 1985, optional equipment weights (p. 35)
[HK] chevrolet/1986-Chevrolet-Cavalier.txt — MVMA specifications, model year 1986, optional equipment weights (p. 37)
[HK] chevrolet/1987-Chevrolet-Cavalier.txt — MVMA specifications, model year 1987, optional equipment weights (p. 37)
[HK] chevrolet/1988-Chevrolet-Cavalier.txt — MVMA specifications, model year 1988, optional equipment weights (p. 42)

Other sources

https://en.wikipedia.org/wiki/Oldsmobile_Firenza — infobox, text, trims, GT section and Engines list (retrieved 2026-11-05 as wikitext, action=raw)
https://en.wikipedia.org/wiki/General_Motors_122_engine — L46 (1982), LQ5 (1983–1986) and LL8 (1987–1988) in the Firenza (retrieved 2026-11-05 as wikitext)
https://en.wikipedia.org/wiki/GM_Family_II_engine — LH8 (1982–1986) and LT2 (1987–1988) in the Firenza (retrieved 2026-11-05 as wikitext)
NICB Passenger Vehicle Identification Manual, GM sections (T4): docs/reference/nicb/nicb1982-gm.txt p.52 and nicb1988-gm.txt pp.71–72, read on the page images — Firenza series and trim names; the engine tables are division-wide and name no car line or RPO code
Web search 2026-11-05 for a Firenza RPO list: nothing usable found