Inside Volvo’s new 13-Liter D13 engine for 2027

At the foundation is a fundamental redesign of the block itself. Volvo switched to compacted graphite iron, increasing tensile strength by 75% over the previous platform.

“That allows us to maintain or increase cylinder pressures,” said Duane Tegels, Volvo Trucks product marketing manager, in an interview with FreightWaves. “So we brought our compression ratio from 18:1 up to 20:1. We’re squeezing that fuel just a little bit more, trying to get every little bit of energy out of it.”

The company also introduced a 14-wave piston design, doubling the wave count from the previous generation. The injector fires directly at one of those waves, splitting fuel in a pattern intended to improve air-fuel mixture and reduce soot.

“Soot is a result of incomplete burn from fuel,” Tegels said. “By changing that design, we reduced the amount of soot that we’re putting into the aftertreatment system, which also affects how many regeneration cycles you have.”

The transmission has been refined to measure input torque more precisely, keeping the engine in its sweet spot longer.

“How it shifts is going to be amazing,” Tegels said. “It’s going to be very seamless; it’s going to pull all the way through the shift. The driver’s going to feel a little bit more acceleration.”

Fuel Economy Varies by Application

Fuel economy gains will depend on the type of operation. Fleets running regional haul or vocational operations with the Variable Geometry Turbo platform will see roughly 4% improvement in fuel economy. Long-haul customers currently running turbo-compounding units will maintain the same efficiency they have today, according to Volvo.

The turbo-compounding unit will sunset in 2027, replaced by a swing-blade VGT design that delivers equivalent performance through the higher compression ratio and refined turbocharger technology.

The engine supports renewable diesel (R100) and biodiesel blends up to B20, providing added flexibility as alternative fuels become more widely available.

Electrical Upgrades Target Component Life

Volvo added a 48-volt alternator alongside the existing 24-volt system, paired with a crankshaft decoupler — essentially an improved harmonic balancer — that stabilizes voltage at idle, protecting alternator components and extending aftertreatment life.

“When you spike voltage up and down, it takes out rectifiers and diodes in alternators,” Tegels said. “So this helps give us clean voltage at low idle and improves the life expectancy of the aftertreatment.”

Two grid heaters — one before the diesel oxidation catalyst and one before the selective catalytic reduction system — increase heat for catalyst conversion, washing out soot and hydrocarbons before the SCR handles NOx reduction. The system builds on aftertreatment technology Volvo has refined over more than a decade in commercial use.

Serviceability Changes

The engine features an exterior-mounted high-pressure fuel pump for the common-rail system, eliminating the need to remove injector cups during injector replacement. The exhaust gas recirculation valve is now electrically actuated rather than hydraulically controlled.

“It gives us better feedback and knowing the position of it so we can mix exhaust gas in there based on cylinder temperature and pressures,” Tegels said.

A variable-displacement coolant pump reduces parasitic loss and provides dynamic cooling based on real-time engine demands. Closed crankcase ventilation runs on an electric motor instead of the oil pump.

The new engine will be available across all Volvo truck models when EPA 2027 standards take effect Jan. 1, 2027. Volvo’s dealer network, parts availability and training programs are also aligned to support adoption from day one.