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VTNA Unveils EPA 2027-Compliant D13 Engine
OEM Promises a Further 4% in Fuel Efficiency
Key Takeaways:
- Volvo Trucks North America unveiled an EPA 2027-compatible D13 engine on May 4 at the Advanced Clean Transportation Expo.
- The 13-liter engine offers up to 540 horsepower and 1,950 pound-feet of torque with improved fuel efficiency.
- VTNA said the engine cuts NOx emissions by more than 80% compared with current standards.
LAS VEGAS — Volvo Trucks North America on May 4 pulled back the curtain on a D13 engine compatible with 2027 Environmental Protection Agency nitrogen oxide emissions standards.
VTNA will offer the engine as part of the standard package for the VNL and VNR on-highway Class 8 tractors.
EPA is still finalizing the regulations for the standards, which will see the agency leave in place a Biden-era requirement that NOx emissions for heavy-duty trucks drop to 35 milligrams per horsepower-hour from 200 mg/hp-hr.
Previously the Trump administration threatened to upend many years of design work and testing for engine manufacturers by possibly revising or retreating from the requirements.
International Motors, Daimler Truck North America and Cummins launched their EPA 2027 engines earlier in 2026.
Kenworth and Peterbilt parent Paccar promised to launch two EPA 2027 engines in February.
VTNA’s 2027 EPA-compatible engine offers up to 540 hp and 1,950 pound-feet of torque, the truck maker announced at the 2026 Advanced Clean Transportation Expo while providing additional fuel efficiency compared with its predecessor for the revamped VNL and VNR tractors.
Legacy D13 engines also offered as much as 1,950 pound-feet of torque, but the top-end horsepower increases from 500 hp. In addition, VTNA boosted the horsepower of the engine brake to 630 hp from 500 hp.
As many as 13 different variations of the engine are available from 405 hp and 1,450 pound-feet of torque up to the maximum 540 hp and 1,950 pound-feet.
To meet the 35-milligram EPA NOx standard, VTNA built upon existing aftertreatment technology.
“What we have done is that we have used the technology that we know. The aftertreatment system is refined in such a way that we can come to the correct emissions,” VTNA President Peter Voorhoeve told ACT Expo attendees.
The 13-liter engine in the revamped VNL was 10% more efficient than its predecessor, while the overhauled VNR was 7.5% more fuel efficient, but the 2027 EPA-compatible configuration will offer another 4% in savings, VTNA’s top executive said.
At the same time, the revised engine reduces NOx emissions by more than 80% compared with current standards.
The engine is compacted graphite iron, which provides an additional tensile strength of about 75%, Product Marketing Manager Duane Tegels told Transport Topics after the unveiling. As a result, the engine has higher in-cylinder pressures.
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Tegels
“What that did is then we changed the compression ratio from 18 to 1 to 20 to 1. We’re squeezing that fuel just a little bit more, trying to get just every little bit of energy out of that,” Tegels said. “So not only can we increase the compression ratio, but we also improved the design of the piston.”
VTNA’s latest engine design has a 14-wave piston. The truck maker only introduced a seven-wave piston in 2024, compared with six waves previously.
Also new for the 2027 EPA-compatible engine is an exterior high-pressure injection pump. Previously, there were three unit injectors pumped by the valve train. The tweak takes pressure off the valve train.
In addition, VTNA altered the exhaust gas recirculation valve from being controlled hydraulically to electrically with the aim of offering a higher degree of precision.
The engine also has a 48-volt alternator plus a 24-volt alternator. The 48-volt alternator is used for the aftertreatment system.
The aftertreatment system has two grid heaters. One is pre-diesel oxidation catalyst and diesel particulate filter and the other before the selective catalytic reduction.
