Chapter ii.
Mk1 vs Mk2
“Mk1” and “Mk2” are enthusiast terms, not official Triumph designations. They were coined after production ended. The car changed relatively little across its run; the differences are trim and cosmetic rather than mechanical.
The most reliable way to place a car is by its commission number. The ranges below are drawn from the Stag Owners Club's records and are approximate at the boundaries.
Commission-number ranges by year
| Commission range | Model year | Enthusiast designation |
|---|---|---|
| 1 – ~3,900 | 1970 pre-production & 1971 | Early / "Mk1" |
| 10,001 – 14,158 | 1972 model year | "Mk1" |
| 20,001 – 25,432 | 1973 model year | Early "Mk2" — matt-black tail panel & sills |
| 30,001 – 36,714 | 1974 / 75 model year | "Mk2" |
| 40,001 – 45,722 | 1976 / 77 model year | Late "Mk2" — body-colour tail panel, alloy sill covers |
Source: Stag Owners Club commission-number records. Boundary commission numbers are approximate.
Visual differences
The features most often used by owners to tell a later “Mk2” car from an earlier “Mk1” at a glance.
- Coach lines
- Twin coach lines on later cars.
- Rear tail panel
- Matt black from the 1973 model year, then body-colour on late cars.
- Wheels
- GKN alloy wheels on later cars.
- Gauges
- Clearer instrument gauges on later cars.
- Steering wheel
- Slightly smaller-diameter wheel.
- Sills
- Matt-black sills from 1973; alloy sill covers on the late cars.
Owners are best advised to verify their car's specification from the commission plate on the scuttle/bulkhead beneath the bonnet, and against the Stag Owners Club register, rather than by eye alone.