GM RPO Decoder
Look up GM RPO codes from the glovebox sticker — axle ratios (GT4, GU6), locking diff (G80), transfer cases, transmissions and more.
Eskimo Auto & Truck Parts — GM RPO Decoder
https://www.eskimoautoandtruckparts.com/tools/rpo-decoder · (780) 473-2424
Reference only — verify against your owner's manual or factory service information before performing any work. Full terms: https://www.eskimoautoandtruckparts.com/tools/terms
The RPO sticker (Service Parts Identification) lives in the glovebox or console lid on most GM vehicles — every 3-character code is an option the truck was built with.
423 codes
| Code | Category | Meaning |
|---|---|---|
| 1LE | Suspension | Track performance packageCamaro; upgraded suspension, brakes, cooling, diff |
| 9C1 | Other | Police packageCaprice/Impala/Tahoe PPV; HD cooling, brakes, electrical |
| A31 | Other | Windows, power-operated, all doorsPower window option code. |
| AJ1 | Other | Glass, deep-tinted (privacy glass, rear/side windows)Excludes windshield and front door glass. |
| AU3 | Other | Door locks, power (electric side-door locks)Power lock option code. |
| B30 | Other | Floor covering, carpet (floor and wheelhouse)Carpeted-floor trim code. |
| B4C | Other | Special service (police) packageCamaro B4C; HD cooling, brakes, drivetrain |
| BG9 | Other | Floor covering, rubber (full floor)Vinyl/rubber floor on fleet and work-truck trims. |
| BTV | Other | Remote vehicle starter systemFactory remote start; on early-2000s trucks it shipped as a prep package requiring dealer-programmed fobs. |
| C36 | Other | Heater, auxiliary (rear)Rear passenger/cargo-area heater on vans, SUVs and crew trucks. |
| C42 | Other | Air conditioning delete (heater only)Fleet/work-truck A/C delete on modern trucks; older passenger-car lists used C42 for the deluxe outside-air heater. |
| C49 | Other | Defogger, rear window, electricHeated rear glass; common on SUVs and trucks with power sliders. |
| C60 | Other | Air conditioning, front, manual (single-zone) controlsBase in-dash A/C code across trucks and SUVs. |
| C69 | Other | Air conditioning, rear auxiliary (front and rear air)Rear A/C on Suburban/Tahoe/Yukon and full-size vans. |
| C6P | Other | Heavy-duty chassis / 8,600-lb GVWR packageIdentifies true HD-rated GMT400 2500s (8-lug, 4L80-E) |
| DF2 | Other | Mirrors, outside, camper-type, manual foldingManual swing-out tow mirrors on older trucks; finished in stainless or black depending on year. |
| DL3 | Other | Mirrors, outside, power-folding, heated, with turn signal indicatorsUpper-trim mirror option on 2014-2019 Silverado/Sierra 1500 and 2015-2019 HD (LTZ, SLT, Denali, High Country). |
| DL8 | Other | Mirrors, outside, power-adjustable, heatedBase power mirror code on 2014-2019 trucks; older lists show it as remote electric with defog. |
| DPN | Other | Mirrors, outside, vertical trailering (camper-style), power-adjustable, heatedFactory vertical tow mirrors on 1500/HD trucks; later years add power fold/extend, turn signals and lower convex glass. |
| E62 | Other | Body equipment, Stepside/Sportside pickup boxFlared step-fender box (Chevy Sportside / GMC Fenderside); offered through the early 2000s. |
| E63 | Other | Body equipment, Fleetside pickup box (wide box)Standard straight-rail wide box; GMC marketed it as Wideside. |
| F40 | Suspension | Heavy-duty front and rear suspension: HD springs and shocks1960s-70s full-size Chevrolets and A-body cars; load-carrying rather than sport calibration |
| F41 | Suspension | Sport/firm ride-and-handling front and rear suspension: stiffer springs, shocks and stabilizer barsLong-running performance suspension: 1960s-70s Camaro/Nova/Chevelle/full-size, B-body through the 1990s |
| F44 | Suspension | Heavy-duty chassis equipment package: HD springs and shocks, typically bundled with upgraded brakes and coolingChevy/GMC pickups 1970s-90s (incl. GMT400 1988-98); exact content varies by year - check brake RPOs (JB5-JB7) alongside it |
| F45 | Suspension | Continuously Variable Real Time Damping: sensor-driven adaptive suspension1996 C4 and 1997-2002 C5 Corvette; related CVRSS systems on 1990s-2000s Cadillacs |
| F48 | Suspension | Manual select damping chassis packageGM dealer-parts RPO list; single-source confirmation only - shown here for completeness of the F-damping family |
| F51 | Suspension | Heavy-duty front and rear shock absorbersClassic Chevrolet car and truck option, 1960s-80s |
| F55 | Suspension | Magnetic Selective Ride Control: continuously variable magnetorheological dampersCorvette C5 (2003-04), C6 and C7; also Cadillac applications - first production MagneRide generation on Corvette |
| F60 | Suspension | Heavy-duty front springsBig-block 1967-69 Camaros and GM pickups (often with snow-plow prep on 1/2-tons); still used on 2000s HD trucks for camper/plow front GAWR |
| FE1 | Suspension | Soft Ride suspension system (base comfort calibration)Bottom level of GM's FE suspension hierarchy, used across GM passenger cars for decades |
| FE2 | Suspension | Ride and Handling suspension system (touring calibration)Mid-level FE suspension; commonly paired with touring packages on GM sedans and F-body/W-body cars |
| FE3 | Suspension | Sport suspension system: stiffer springs, shocks and stabilizer barsSport level of the FE hierarchy; seen on Olds 442/Trofeo, Chevy SS models, Buick GN-era cars and many others |
| FE4 | Suspension | Special ride and handling suspension systemOn 4th-gen F-body a firm 'special' calibration; on gen-5/6 Camaro ZL1/SS 1LE and C8 Corvette Z51 cars FE4 denotes the Magnetic Ride Control suspension |
| FE5 | Suspension | Performance suspension system (ride, handling, performance calibration)Top non-adaptive level of GM's FE suspension hierarchy on 2000s+ cars |
| FE9 | Other | Federal (49/50-state) emissions certification - NOT a suspension codeAppears on nearly every US-spec GM RPO label; frequently mistaken for a ride package because of the FE prefix |
| FG2 | Suspension | Firm-ride front and rear shock absorbersShock calibration code paired with sport suspensions on 1980s-90s GM cars |
| FX3 | Suspension | Selective Ride Control: driver-adjustable electronic damping (Tour/Sport/Performance)1989-1995 C4 Corvette; cockpit switch adjusts Bilstein shock valving |
| G44 | Axle Ratio | Rear axle, 3.07:1 ratio |
| G72 | Axle Ratio | Rear axle, 2.14:1 ratio |
| G75 | Axle Ratio | Rear axle, 3.62:1 ratio |
| G76 | Differential | Positraction (limited-slip) rear axleOlder Positraction option code; appears in GM axle references alongside G80/G81 |
| G80 | Differential | Locking / limited-slip rear differential (traction adder)Classic cars: Positraction clutch-type limited slip. Light trucks (GMT400/800/900 through current Silverado/Sierra): Eaton 'Gov-Lock' automatic locking differential — open in normal driving, locks both axles on wheel slip |
| G81 | Differential | Positraction rear axle (limited slip)Positraction option code used on various GM cars/trucks |
| G82 | Axle Ratio | Rear axle, 4.56:1 ratio |
| G84 | Axle Ratio | Rear axle, 4.10:1 ratio |
| G86 | Differential | Rear axle, limited-slip differentialClutch-type limited slip; e.g., 2004-06 Pontiac GTO and other RWD cars |
| G87 | Differential | Ring gear, 8.5 inchIdentifies GM 8.5-inch 10-bolt rear axle |
| G89 | Differential | Ring gear, 7.5 inchIdentifies GM 7.5-inch 10-bolt rear axle (S-10, F-body, etc.) |
| G90 | Axle Ratio | Rear axle, 3.15:1 ratio |
| G91 | Axle Ratio | Special highway rear axle, 3.08:1 ratio |
| G92 | Axle Ratio | Performance axle ratio (package code)Marker, not a specific ratio — accompanying G-code gives the ratio. E.g., on 1982-2002 Camaro/Firebird it replaced GU2 2.73 with GU5 3.23; 1993 G92 also included engine oil cooler and 150-mph speedometer |
| G94 | Axle Ratio | Rear axle, 3.31:1 ratio |
| G96 | Axle Ratio | Rear axle, 3.55:1 ratio |
| G97 | Axle Ratio | Rear axle, 2.73:1 ratio |
| GH0 | Axle Ratio | Rear axle, 3.54:1 ratio |
| GH3 | Axle Ratio | Rear axle, 2.77:1 ratio |
| GH4 | Axle Ratio | Rear axle, 2.92:1 ratio |
| GH7 | Axle Ratio | Rear axle, 2.73:1 ratio |
| GJ1 | Axle Ratio | Rear axle, 5.38:1 ratio |
| GJ2 | Axle Ratio | Rear axle, 5.13:1 ratio |
| GK7 | Axle Ratio | Rear axle, 4.78:1 ratio |
| GK8 | Axle Ratio | Rear axle, 4.33:1 ratio |
| GK9 | Axle Ratio | Rear axle, 4.63:1 ratio |
| GM1 | Axle Ratio | Rear axle, 2.59:1 ratio |
| GM2 | Axle Ratio | Rear axle, 3.44:1 ratio |
| GM3 | Axle Ratio | Rear axle, 3.45:1 ratio |
| GM4 | Axle Ratio | Rear axle, 3.67:1 ratio |
| GM5 | Axle Ratio | Rear axle, 3.89:1 ratio |
| GM6 | Axle Ratio | Rear axle, 4.22:1 ratio |
| GM7 | Axle Ratio | Rear axle, 3.68:1 ratio |
| GM8 | Axle Ratio | Rear axle, 2.56:1 ratio |
| GQ1 | Axle Ratio | Rear axle, standard (base) ratioPlaceholder code — actual ratio varies by model/year and is given by the companion GU_/GT_ code on the RPO label; open differential unless G80 is also present |
| GS1 | Axle Ratio | Rear axle, 2.73:1 ratio |
| GS3 | Axle Ratio | Rear axle, 3.73:1 ratio |
| GS4 | Axle Ratio | Rear axle, 3.70:1 ratio |
| GS5 | Axle Ratio | Rear axle, 4.11:1 ratio |
| GS6 | Axle Ratio | Rear axle, 4.56:1 ratio |
| GS8 | Axle Ratio | Rear axle, 3.94:1 ratio |
| GT1 | Axle Ratio | Rear axle, 2.56:1 ratio |
| GT2 | Axle Ratio | Rear axle, 2.29:1 ratio |
| GT4 | Axle Ratio | Rear axle, 3.73:1 ratioPopular towing ratio on 1988+ GM full-size trucks/SUVs (GMT400/800/900) |
| GT5 | Axle Ratio | Rear axle, 4.10:1 ratioMax-trailering / HD ratio on GM trucks; strong low-end pull, higher cruise RPM |
| GT7 | Axle Ratio | Rear axle, 3.33:1 ratio |
| GT8 | Axle Ratio | Rear axle, 4.10:1 ratioListed in GM references as a duplicate of GT5 |
| GU1 | Axle Ratio | Rear axle, 2.41:1 ratio |
| GU2 | Axle Ratio | Rear axle, 2.73:1 ratioCommon standard ratio on 1980s-90s F-body/B-body cars and light trucks |
| GU3 | Axle Ratio | Rear axle, 2.93:1 ratio |
| GU4 | Axle Ratio | Rear axle, 3.08:1 ratioHighway/fuel-economy ratio on GM trucks; not suited to heavy towing |
| GU5 | Axle Ratio | Rear axle, 3.23:1 ratioBalance of mileage and light-duty towing; also the F-body G92 performance ratio |
| GU6 | Axle Ratio | Rear axle, 3.42:1 ratioOne of the most common half-ton ratios (Silverado/Sierra/Tahoe/Suburban, 1988+) |
| GU7 | Axle Ratio | Rear axle, 2.77:1 ratio |
| GU8 | Axle Ratio | Rear axle, 3.90:1 ratio |
| GU9 | Axle Ratio | Rear axle, 3.91:1 ratio |
| GV0 | Axle Ratio | Rear axle, 3.55:1 ratio |
| GV1 | Axle Ratio | Rear axle, 2.73:1 ratio |
| GV2 | Axle Ratio | Rear axle, 5.83:1 ratio |
| GV3 | Axle Ratio | Rear axle, 3.08:1 ratio |
| GV4 | Axle Ratio | Rear axle, 3.36:1 ratio |
| GV5 | Axle Ratio | Rear axle, 3.55:1 ratio |
| GV7 | Axle Ratio | Rear axle, 4.11:1 ratio |
Showing first 100 of 423 — narrow with a letter, category, or search.
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Reference information only, provided "as is" without warranty. Specs vary by exact vehicle, trim, and production date — always verify torque figures, capacities, and fitment against your owner's manual or factory service information before performing any work. Tool Terms of Use.
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