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EPA 2027 Engine Compliance | International® S13® Integrated Powertrain

Mar. 4 2026 News By Cal Pacific Truck Center

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A new era of heavy‑duty efficiency is taking shape as the International® S13® Integrated Powertrain moves confidently into EPA 2027. What makes this transition remarkable is not a dramatic redesign, but the opposite: intentional simplicity, proven hardware, and targeted refinements that deliver compliance without compromising performance, serviceability, or uptime.


The Foundation: A Proven, Fuel‑Efficient Platform

With more than two years of real‑world production, the current S13® Integrated Powertrain has already established itself as a fuel‑economy leader in head‑to‑head TMC Type IV testing. Its streamlined architecture—no EGR cooler, no DOC, no fuel dosing, and a compact dual‑stage aftertreatment system—has set a new standard for simplicity and efficiency.

For 2027, ~90% of the hardware carries over, meaning fleets retain familiar service tools, training, parts, and maintenance practices. The powertrain also remains weight‑neutral, preserving payload advantages.


What Stays the Same

The core strengths of the S13® platform remain unchanged:

  • S13® Engine — Lightest 13L in North America, DOHC design, 23:1 compression ratio, fixed‑geometry turbo, and smart DEF dosing for superior NOx control.

  • T14® Transmission — The industry’s most compact 14‑speed, featuring a planetary gearset, fast ECA shifting, integrated oil cooling, and factory‑installed PTO options with full warranty support.

  • Dual‑Stage Aftertreatment — Same packaging, no pre‑heating elements, and no need for a 48V grid heater to meet 2027 NOx standards.

  • Maintenance Continuity — Planned Maintenance contracts minimize operational disruption and keep technician training and parts inventory consistent.


What’s New for 2027

While the platform remains familiar, several strategic enhancements elevate performance, drivability, and emissions control:

  • Elimination of External EGR — Simplifies the system and removes the previous crossover tube.

  • Variable Valve Timing (VVT) — Adjusts valve timing in real time for smoother power delivery, improved efficiency, and cleaner combustion.

  • Variable Valve Braking (VVB) — Boosts engine braking from 470 hp to 560 hp, improving safety and brake life.

  • Closed Crankcase Breather & Oil Centrifuge — Reduce emissions and maintain oil quality over long intervals.

  • 24V Powertrain Architecture — More robust global‑scale components, improved cold‑crank performance, and longer starter/battery life—while the cab and chassis remain 12V for body‑builder compatibility.

  • Updated TCM — A 24V module that uses learned driver behavior, GPS, and topography to optimize shifting for fuel economy and performance.


Designed for a Seamless Transition

The 2027 S13® Integrated Powertrain is built around a simple idea: compliance shouldn’t come at the cost of complexity. By refining a proven platform instead of reinventing it, International® delivers a solution that is cleaner, smarter, and easier to adopt—without burdening fleets with new tools, new training, or new maintenance routines.

The result is a powertrain that meets EPA 2027 standards while preserving the attributes fleets value most: uptime, efficiency, durability, and driver‑friendly performance.