The SDEC R Series engines are 2.5–2.8 L (2,499–2,776 cc) Inline-4 diesel engines from SDEC.

They are light-duty truck engines based on licensed VM Motori designs.

SDEC R Series engines use a non-fixed naming convention: 2.5L light-duty truck engine based on VM Motori RA 425 DOHC.

Light-duty truck engines based on VM Motori RA 428 DOHC.

Based on a tunnel closed cylinder block design, 4-valves per cylinder, high pressure 1600bar BOSCH common rail system, aluminum alloy cylinder head, double overhead cam system and volute casing fixed geometry turbocharger or electronically controlled variable geometry turbocharger, complying with China/Euro 4, 5A and 6 emission standards.