Which engines have EGR?
Most modern diesel engines and many gasoline engines include Exhaust Gas Recirculation (EGR) to curb NOx emissions. Electric vehicles, by contrast, do not have EGR since there is no exhaust gas to recirculate.
This article explains which engines typically use EGR, how the system varies between diesel and gasoline engines, and what to look for if you’re trying to determine whether a specific engine includes EGR or how it might behave in maintenance and performance scenarios.
Engines that typically include EGR
The following list highlights engine types where EGR is standard practice or widely implemented in modern vehicles.
- Modern diesel engines across passenger cars, light trucks, and heavy-duty applications. EGR is nearly universal in diesel powertrains to meet NOx limits, often paired with cooling and other aftertreatment methods (such as selective catalytic reduction).
- Gasoline engines with turbocharging and/or direct injection (GDI). Since the late 2000s and into the 2010s, many GDI engines adopted EGR to reduce NOx while maintaining efficiency and performance.
- Some naturally aspirated gasoline engines, especially in markets with stringent emissions standards, that use EGR as part of a broader NOx-control strategy.
- Hybrid and plug-in hybrid systems that continue to run the internal combustion engine under certain conditions may use EGR during engine operation to balance NOx and efficiency.
- Industrial and marine engines designed to meet contemporary emissions regulations, where EGR is a common tool for NOx reduction across larger displacement ranges.
In practice, EGR is a standard feature on the majority of modern diesel engines and a large share of gasoline engines—particularly turbocharged or direct-injected variants. To confirm for a specific model, check the owner’s manual, service documentation, or repair guides for details on the EGR valve, cooler, and related plumbing.
Engines and situations where EGR may be absent or limited
The following list covers scenarios where EGR is not universally used or may be restricted under certain conditions.
- Electric vehicles (EVs) and most non-combustion-drive systems do not have exhaust systems or EGR, since there is no exhaust gas to recirculate.
- Some small-displacement gasoline engines designed for markets with less stringent NOx regulations may omit EGR entirely, though many have adopted it as emissions standards tightened.
- High-performance or racing-oriented engines may temporarily limit or disable EGR at wide-open throttle to maximize power, with modern controls still ensuring regulatory compliance under typical driving.
- Two-stroke engines or certain non-road engines often rely on alternative emissions strategies and may not use conventional EGR in the way most four-stroke automotive engines do.
Despite these exceptions, ongoing regulatory pressure tends to push more engines—especially gasoline turbocharged and diesel designs—toward incorporating EGR or equivalent NOx-control strategies over time.
Key EGR components and how they interact
Most EGR systems include an EGR valve that modulates the amount of exhaust gas reintroduced into the intake, an EGR cooler to reduce gas temperature before re-entry, and associated plumbing between the exhaust and intake paths. Modern vehicles use electronic controllers to optimize EGR flow based on engine load, speed, temperature, and emissions thresholds.
Common signs of EGR problems
When an EGR system begins to fail, drivers may notice rough idle, engine surges, reduced performance, increased fuel consumption, or the check engine light illuminating. A failed EGR valve or clogged EGR passages can cause NOx increases and drivability issues. If you suspect EGR issues, a professional diagnostic is recommended to isolate valve faults, cooler clogging, or related sensors.
Summary
Today, EGR is a standard feature on most modern diesel engines and a large portion of gasoline engines—especially those with turbocharging or direct injection. EVs do not use EGR, and there are occasional exceptions where EGR is not employed or is limited under certain conditions. Understanding whether a given engine uses EGR, and how its system is configured (high-pressure, low-pressure, cooled, etc.), helps in diagnosing emissions-related concerns and planning maintenance. If in doubt, consult vehicle specifications or a qualified technician for confirmation and service guidance.
Do gasoline engines have an EGR?
External Exhaust Gas Recirculation (EGR) has been used on diesel engines for decades and has also been used on gasoline engines in the past. It is recently reintroduced on gasoline engines to improve fuel economy at mid and high engine load conditions, where EGR can reduce throttling losses and fuel enrichment.
Do naturally aspirated engines have an EGR?
The implementation of EGR is simple for naturally aspirated gasoline engines, since exhaust tailpipe backpressure is normally higher than intake pressure. With the development of downsized gasoline engine, turbocharged gasoline engine is becoming increasingly popular in the market.
What engines have an EGR?
In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide (NO x) emissions reduction technique used in petrol/gasoline, diesel engines and some hydrogen engines.
Do diesel engines have an EGR valve?
The EGR (Exhaust Gas Recirculation) valve is a vital component found in diesel engines. Its primary function is to reduce nitrogen oxide (NOx) emissions by recirculating a portion of the engine's exhaust gas back into the combustion chamber.
