See What Your Car Sees: The ECU Widget Explained

March 25, 2026

Available with Update 2.0 is the Project Motor Racing real-time telemetry system that reveals the forces, power, and energy of your car instant-by-instant, lap-by-lap. The ECU Widget.

Fore more details on Update 2.0 read this article.

For a full breakdown, read the patch notes.

Modern racing machines generate huge amounts of data. In Project Motor Racing, the Electronic Control Unit (ECU) Widget transforms that data into a clear visual dashboard, helping you understand exactly what your car is doing while you’re on track.

From load distribution and tyre behaviour to power delivery and fuel usage, the ECU Widget offers a multifaceted look into the systems that define your performance.

Designed for drivers who want to understand the mechanics behind lap time, this widget provides a powerful diagnostic tool.

Because every car uses a slightly different electronic architecture, not every sensor will be available on every vehicle. Some indicators may therefore appear inactive depending on the car you’re driving. For example, vehicles without front‑wheel drive will not display power on the front drivetrain indicators.

The widget is disabled by default. To activate it on your HUD, go to the HUD settings in your Cockpit Setup and turn it on.

ECU Status

Let’s take a look at it and explain what it all does.

At the top of the widget is the ECU Status indicator, which shows whether the system is currently receiving sensor data.

Active: One or more sensor channels have been detected and are reporting live telemetry.

Not Connected: No sensors were found. While all official Straight4 Studios vehicles include sensor systems, modded cars may not implement them. In those cases, the widget data remains inactive.

Loads: Understanding Weight Transfer

The Loads section visualises how forces are distributed across the car. In this view, the left side represents the front of the car, while the right side represents the rear.

Tyre Load: A vertical bar above the reference line represents the total load acting on the tyres. The height shows how much load is present, while the position shows where that load is concentrated.

Aerodynamic Load: Below the reference line, another bar represents aerodynamic downforce. Its size indicates total downforce while its position shows the centre of pressure.

Centre of Gravity: A vertical line marks the car’s centre of gravity. This position may shift slightly during a race as fuel load decreases.

Scrub Bubble: The gold bar shows the rolling range of tyre slide while the black bubble shows the current balance between front and rear slip. Movement to the left indicates more front scrub (understeer), while movement to the right indicates more rear scrub (oversteer).

Power: Tracking Energy Through the Drivetrain

The Power section contains several indicators related to power delivery.

On the left side of the widget, four vertical bars show overall power flow from key drivetrain systems. Each bar represents a specific power channel and displays its output in kilowatts (kW).

The four power bars are:

• Front Half Shafts (F)
• Rear Half Shafts (R)
• Electrical Power (E)
• Auxiliary Power Sensor (X)

Each bar changes colour based on power direction:

• Green indicates positive power delivery.
• Red indicates negative power, such as braking or regeneration.

A numeric value in kW is also displayed to show the current power level.

On the right side are indicators showing power activity across specific drivetrain and power-delivery components within the vehicle.

Let’s take a look at the power bars and what they mean.

Power Bars Detail

To understand what is being shown, a quick understanding of the half-shaft is necessary. Half-shaft power shows how much power actually reaches the wheels. Watching it helps you understand traction, drivetrain behaviour, and how your car delivers power on track. For example: Too much rear half-shaft power means probably oversteer on throttle. And if you’re seeing inconsistent power delivery, this is traction control intervention severing the power going to the wheels.

Front Half Shafts Power (F): Power measured as the sum of the two front half shafts.

Rear Half Shafts Power (R): Power measured as the sum of the two rear half shafts.

Electrical Power (E): Displays power flow into the battery. Positive values indicate regeneration, while negative values indicate deployment. This display is inverted relative to half‑shaft power because regeneration is typically larger than deployment and the widget provides more display space on this side.

Auxiliary Power Sensor (X): This channel is defined by the ECU or mod implementation and may vary depending on the vehicle.

Powertrain Components

The powertrain visualisation on the right side of the widget is arranged to reflect the vehicle layout: the top represents the front of the car, and the bottom represents the rear.

Power blocks transition from bright red during negative power events (such as braking) to bright green during positive power delivery.

To understand what you’re seeing, it’s important to understand what the differential does for your car’s traction and cornering.

A differential splits power between the left and right wheels while allowing them to rotate at different speeds when the car turns. In the ECU widget, seeing how much the differential is locking helps explain how the car delivers power to the ground—more locking can improve traction on corner exit, while less locking can help the car rotate more easily.

Front and Rear Differential Locking: Thin gold bars at the top and bottom of the display represent differential locking. As locking increases the bars widen. At 100% locking the bar reaches the same width as the half‑shaft indicators.

Front Half Shafts: Two horizontal blocks at the top represent the front half shafts. These typically show activity only in vehicles with front‑wheel drive or all‑wheel drive.

Front Drive Shaft: Located below the front half shafts and typically active only in vehicles with FWD or AWD layouts.

Front MGU: Motor Generator Unit is an electric motor used in hybrid race cars that can both generate electricity and provide additional power to the drivetrain. A smaller block located between the front drive shaft and the engine block representing the front motor generator unit.

Internal Combustion Engine (ICE): The large central block representing the engine.

Rear MGU: The smaller block below the engine representing the rear motor generator unit.

Rear Drive Shaft: Located below the rear MGU and transmitting power toward the rear axle.

Rear Half Shafts: Represent power delivered to the rear wheels.

Rear Differential Locking: A thin gold bar at the bottom that widens as locking increases, reaching the same width as the half‑shaft indicators at 100% lock.

Fuel: Managing Your Stint

The Fuel section provides information that can be critical for race strategy.

Fuel Flow Rate shows current fuel consumption as both a number and a bar. A secondary hash mark indicator shows a smoothed average to help track trends.

Lap Estimate predicts how many laps remain with the current fuel load based on the previous lap’s usage.

Please note: the lower portion of the ECU Widget, engine mapping, is currently only functional in LMDh cars. We will make this function compatible with other cars in a future update.

Driver Tips Using the ECU Widget

If you notice the scrub bubble shifting heavily toward the front during corner entry, you may be overloading the front tyres. Try adjusting brake balance or easing steering input.

Did You Know?

Aerodynamic centre of pressure moves depending on speed. Watching the aero load bar during fast corners can reveal how your car’s balance changes as downforce builds.

Pro Insight

Monitoring electrical power alongside drivetrain power can help you optimise hybrid deployment and regeneration strategies in longer races.

The FFB Widget

Also coming to version 2.0 is the FFB Widget, which is enabled by default.

The vertical bars form a force feedback histogram that samples only while steering input is applied.

The rightmost bar represents force saturation.

The horizontal bar shows the current force feedback output level.

A yellow hash mark and numeric value represent a smoothed force feedback level while steering. This helps compare force feedback levels between different setups or cars.

The widget also displays pedal inputs so you can see how throttle, brake, and clutch inputs are being registered in game.

A Deeper View of Performance

The ECU Widget adds another layer of understanding to the driving experience in Project Motor Racing.

By translating complex telemetry into intuitive visual indicators, it allows drivers to see how the car responds to every input and every section of the track at every single instant.

Whether you are analysing load transfer through a fast corner, monitoring hybrid deployment, or managing fuel over a race stint, the ECU Widget gives you a clearer picture of the machine beneath you and the performance you can unlock from it by focusing on where your telemetry is not optimal and working on your car’s setup to reach the closest to optimal possible.

Discuss and share your feedback in our community forum or in the official Discord server.