Volvo Trucks seeking CARB 0.05 g/bhp·hr NOx certification for D13 diesel engine

2 May 2025

Volvo Trucks North America announced that it will apply for certification of a new heavy-duty D13 diesel engine that it expects will meet the California Air Resources Board’s (CARB) 2024 Omnibus emission standards. The engine is designed to obtain a certification at the 0.05 g/bhp·hr NOx emission standard.

Volvo received its first CARB-24 certification for the D13 engine in December 2023 and announced the commercial availability of the engine in July 2024. However, the engine was certified to NOx emission levels higher than the 0.05 g standard, with compliance achieved through the use of emission credits.

The new engine will be built on the new Volvo D13 VGT (Variable Geometry Turbo) engine platform. Once certified, customers will be able to order the engine in the Volvo VNL and VNR truck models with expected configurations of 425 hp/1,750 lb-ft torque and 455 hp/1,850 lb-ft torque.

The new D13 VGT engine will enhance fuel efficiency through a shorter seven-wave piston for improved combustion, a longer connecting rod to reduce friction, a precision needle control valve for optimized fuel flow, and a variable displacement oil pump to minimize parasitic losses.

The CARB-24 D13 VGT engine features a linear exhaust aftertreatment system (EATS) with a 48-volt heater used to support the SCR catalyst during startup and low-load operation to achieve the ultra-low NOx emission targets. Each EATS component is designed for individual servicing or replacement.

Volvo expects the deliveries of trucks with the new engine would begin in the fourth quarter of 2025.

Source: Volvo Trucks