Help Guide: How to Identify Your Motorcycle's Emissions Rating: Triumph Euro 4 vs Euro 5 vs Euro 5+

A Hitchcox Motorcycles guide to choosing the right aftermarket exhaust for your Triumph's exact emissions specification

If you're looking to upgrade your Triumph with a new aftermarket exhaust system, one of the first things you'll need to know is your motorcycle's Euro emissions rating.

Many riders know their bike's model and registration year, but aren't always sure whether it's a Euro 4, Euro 5 or Euro 5+ model. Unfortunately, ordering parts based on the wrong emissions standard can lead to compatibility issues, as manufacturers often make changes to exhaust systems, catalytic converters, sensors and ECU mapping when new regulations are introduced.

The good news is that identifying your Triumph's Euro rating is usually straightforward once you know what to look for.

In this guide, we'll explain what Euro emissions standards are, why they matter, and how to identify the correct rating for your motorcycle before ordering aftermarket exhaust parts.

What Are Euro Emissions Standards?

Euro emissions standards are regulations introduced across Europe to reduce vehicle emissions and improve air quality.

Every time a new Euro standard is introduced, manufacturers must make changes to ensure their motorcycles meet stricter environmental requirements. These changes often involve updates to the engine management system, catalytic converter, exhaust design and emissions monitoring equipment.

For motorcycle owners, this means that two bikes which appear almost identical can have important differences underneath the bodywork.

That's why many aftermarket parts, particularly Triumph exhaust systems, are designed specifically for Euro 4, Euro 5 or Euro 5+ models.

Why Does Your Euro Rating Matter?

When purchasing aftermarket exhaust parts, your Euro rating is often more important than the registration plate.

A system designed for a Euro 5 motorcycle may not fit a Euro 4 model correctly, even if both bikes share the same name and overall appearance.

Differences can include:

• Exhaust mounting points
• Header pipe design
• Catalytic converter location
• Oxygen sensor placement
• ECU calibration
• Silencer dimensions

Before ordering any exhaust system, it's always worth confirming your motorcycle's Euro rating to ensure you receive the correct parts.

Understanding Euro 4

Euro 4 regulations were introduced for newly approved motorcycle models in 2016 and became standard on most new motorcycles from 2017 onwards.

Compared to previous regulations, Euro 4 introduced:

• Stricter emissions limits
• Mandatory ABS on larger motorcycles
• Improved evaporative emissions controls
• More advanced fuel injection systems

Many popular Triumph models such as the Bonneville T100, Bonneville T120, Street Twin and Street Scrambler were updated to comply with Euro 4 requirements.

Today, most Triumph motorcycles produced between 2016 and 2020 fall into the Euro 4 category.

Understanding Euro 5

Euro 5 became the next major step in emissions compliance and was introduced on most new motorcycles from 2021 onwards.

The regulations further reduced allowable emissions and required manufacturers to improve engine efficiency and exhaust after-treatment systems.

Common changes included:

• Larger or more efficient catalytic converters
• Updated ECU software
• Revised exhaust routing
• Additional emissions monitoring systems

Although many Euro 5 Triumphs look almost identical to their Euro 4 predecessors, important technical differences can affect aftermarket exhaust compatibility.

As a general rule, most Triumph motorcycles produced between 2021 and 2024 are Euro 5 models.

What Is Euro 5+?

Euro 5+ is the latest evolution of the Euro 5 emissions regulations.

For Triumph owners, Euro 5+ is mostly found on 2025 model-year motorcycles onwards.

Rather than focusing solely on reducing emissions when the motorcycle is new, Euro 5+ places greater emphasis on ensuring emissions systems continue to perform correctly throughout the bike's lifespan.

Additional requirements include:

• More advanced onboard diagnostics
• Enhanced emissions monitoring
• Stricter durability testing
• Improved fault detection systems

While the physical differences between Euro 5 and Euro 5+ motorcycles may not always be immediately obvious, there can still be changes that affect aftermarket exhaust compatibility.

If you own a 2025 model-year Triumph or newer, it is important to confirm that any exhaust system you purchase is specifically designed for Euro 5+ compatibility.

How to Identify Your Triumph's Euro Rating

1. Check the Model Year

The easiest place to start is by identifying your motorcycle's model year.

As a general guide:

While this is accurate for most Triumph models, it should be treated as a guide rather than a guarantee. Motorcycles can sometimes be registered later than their actual model year, particularly if they remained unsold in dealer stock.

2. Check Your VIN Number

Your VIN (Vehicle Identification Number) is one of the most reliable ways to confirm your motorcycle's exact specification.

If you're unsure about compatibility, providing your VIN to the supplier will usually allow them to identify the correct version of your bike.

3. Check Your V5C Logbook

Your V5C registration document may contain emissions information that can help confirm your motorcycle's specification.

This can be particularly useful when purchasing a used motorcycle.

4. Review Original Documentation

Owner's manuals, sales invoices and dealer paperwork often contain details about the motorcycle's model specification and emissions compliance.

If you still have the original documentation, it can be a useful reference point.

5. Contact the Supplier Before Ordering

If you're ever unsure, it's always worth asking before placing an order.

Providing the following information will usually allow compatibility to be confirmed quickly:

• Motorcycle model
• Model year
• Registration year
• VIN number
• Photos of the existing exhaust system (if applicable)

A quick check beforehand can save a lot of time and frustration later. If your bike's CAT is welded to the link pipes, it's definitely a Euro 5+. Previous versions had clamps instead.

Common Triumph Model Examples

The following examples provide a useful guide for some of Triumph's most popular modern classics.

Bonneville T100

• Most 2017–2020 models are Euro 4
• Most 2021–2024 models are Euro 5
• Most 2025 onwards models are Euro 5+

Bonneville T120

• Most 2016–2020 models are Euro 4
• Most 2021–2024 models are Euro 5
• Most 2025 onwards models are Euro 5+

Street Twin / Speed Twin 900

• Earlier models are typically Euro 4
• Most 2021–2024 models are Euro 5
• Most 2025 onwards models are Euro 5+

Street Scrambler / Scrambler 900

• Most 2017–2020 models are Euro 4
• Most 2021–2024 models are Euro 5
• Most 2025 onwards models are Euro 5+

Always verify the exact specification of your individual motorcycle before purchasing aftermarket exhaust parts.

Common Mistakes Riders Make

Assuming the Registration Year Tells the Whole Story

A motorcycle first registered in a particular year may have been manufactured during the previous model year. That's why model year and VIN information are often more reliable than the registration plate alone.

Ordering Based on Appearance

Many Euro 4, Euro 5 and Euro 5+ Triumph motorcycles look almost identical from the outside. Small technical differences can still have a significant impact on compatibility.

Assuming Every Exhaust Fits Every Version

Even minor changes to mounting brackets, catalytic converters or sensor locations can mean that an exhaust designed for one emissions standard will not fit another correctly.

Need Help Identifying Your Triumph?

If you're unsure whether your motorcycle is Euro 4, Euro 5 or Euro 5+, we're happy to help. Simply contact us with your motorcycle's model, model year and VIN number, and we'll help identify the correct specification before you order.

Taking a few minutes to confirm compatibility now can help ensure you receive the correct parts the first time.

Quick Summary

• Euro 4: Typically Triumph models from 2016–2020
• Euro 5: Typically Triumph models from 2021–2024
• Euro 5+: Typically Triumph models from 2025 onwards
• Model year is a useful guide, but not a guarantee
• VIN numbers provide the most reliable way to confirm compatibility
• Always check your Euro rating before ordering exhaust components
• When in doubt, contact the supplier before purchasing

Knowing your motorcycle's Euro rating is one of the simplest ways to ensure you choose the correct aftermarket exhaust system and avoid unnecessary compatibility issues. Whether you're upgrading a Bonneville, Speed Twin or Scrambler, a quick check now can save time, money and hassle later.

Not sure which Euro rating your Triumph falls under? Get in touch with the Hitchcox Motorcycles team with your model, model year and VIN, and we'll help you find the right aftermarket exhaust the first time.