The Marcos 1800 GT was first introduced in 1964 by Marcos Engineering LTD as their first mass produced car. This low coupé was originally fitted with a cast iron P18 Volvo powertrain but would see many iterations across its production. The car was produced in two phases, the first one lasting from 1964-1972 until it was later resurrected for a final run from 1981-1990.
| Brand | Volvo |
| Configuration | Straight 4, OHV, 1.8L |
| Construction | Cast Iron |
| Displacement | 1779 cc |
| Bore/stroke | 84,14 mm / 80,00 mm |
| Aspiration | Naturally aspiration |
| Fuel Feed | Weber 45 DCOE |
| Clutch Type | Hydraulic |
| Actuation | Slave Cylinder External |
| Number of gears | 4 forward, 1 reverse |
| 1st Gear | 33/15 |
| 2nd Gear | 28/20 |
| 3rd Gear | 22/23 |
| 4th Gear | Direct |