How Does Mild Hybrid Technology Work?
Summary
You've been browsing new cars and found one you like. You've spotted the letters MHT or MHEV and are wondering what an MHEV is?
It sounds technical, but it doesn't need to be. Here's what it actually means, how it works, and the benefits of driving an MHEV.
The 48V Mild Hybrid System and Why the Voltage Matters
Most cars run on a 12V electrical system. It powers the electrical systems in every car, such as your lights, infotainment, heated seats, and other electrical features. It is perfectly adequate for those tasks, but lacks the power to provide meaningful assistance to a combustion engine.
That is where the 48V mild hybrid technology comes into play. Increasing the volts from 12 to 48 quadruples the electrical power available. This higher voltage enables more efficient power delivery, which supports engine operation and reduces fuel consumption. It is the difference between a system that can keep the lights on and one that can lighten the engine's workload to improve efficiency.
The two systems work together. A DC/DC converter steps the 48V mild hybrid supply down to 12V for all your standard electrical components, so everything works exactly as it always has.
The Belt-Starter Generator: The Component Doing the Work
At the heart of every mild hybrid technology system is the Belt-Starter Generator, or BSG. It is a compact unit mounted on the front of the engine, driven by the same serpentine belt that runs the alternator on a conventional car. In fact, it replaces the alternator entirely and takes on two jobs at once.
Here is the process of how it works:
During Deceleration and Braking
When the driver lifts off the accelerator, the BSG captures rotational energy from the engine and converts it into electrical energy. This recovered energy charges the 48V mild hybrid battery. Energy that would otherwise be lost as heat is recycled back into the system. This is regenerative braking.
During Acceleration
The BSG uses the stored electrical energy that’s been built up to apply torque through the belt drive, aiding the engine in accelerating. This additional torque helps reduce fuel consumption and improve the performance of the vehicle.
During Stop/Start
Because the BSG is belt-driven, it can spin the crankshaft more smoothly and quickly than a conventional starter motor. This allows manufacturers to perform frequent engine stop-start without the harsh wear associated with traditional starter systems. The result is a stop-start system that is seamless rather than the slightly clunky experience of older technology.
Benefits of Owning a Mild Hybrid
With MHEVs, the benefits are subtle, but they create immense value for everyday driving.
The throttle response is more immediate, making pulling away in stop-start traffic cleaner. Stop/start technology works seamlessly, allowing for savings on fuel with every journey.
For motorway cruising, a number of mild hybrid systems offer a sailing or gliding function, where the engine shuts off at constant speed, it maintains the momentum with battery support before re-engaging when the driver touches the accelerator.
For daily driving, the gains are valuable. Every time you get behind the wheel and brake or accelerate, the system is recycling energy. The result is improved fuel economy, which gives you seriously impressive mpg. And the best bit is that you don’t have to change anything about the way you drive to reap the rewards.
Dick Lovett Brands Utilising Mild Hybrid Technology
A range of our brands offer mild hybrid technology across their range; however, two standout brands that have built this technology into their core model lineup are BMW and Land Rover.
BMW Mild Hybrid Technology Across the Core Range
BMW calls its system BMW MHT (Mild Hybrid Technology) and has now featured it in almost all new four and six-cylinder petrol and diesel engines across its model lineup. The chances are, if you don't choose an all-electric or plug-in hybrid BMW, your next new car will have an engine backed up by BMW MHT.
BMW is deliberate about describing MHT as a performance enhancement as much as an efficiency one. The system doesn't dull the driving experience in pursuit of better fuel figures. It uses the recovered energy to make the engine feel more engaging, while the efficiency benefits follow naturally.
Browse our latest MHT BMW models at Dick Lovett
MINI Mild Hybrid Technology Across the Range
MINI has embraced mild hybrid technology across selected petrol models, blending the brand’s trademark go-kart handling with greater efficiency and everyday usability.
MINI’s Mild Hybrid Electric Vehicle (MHEV) system works behind the scenes to support the combustion engine during acceleration, recovering energy when braking and storing it in a compact battery. Rather than changing the character of the drive, the system enhances it, delivering smoother power delivery and extra responsiveness when pulling away or overtaking.
The added electrical assistance helps reduce fuel consumption and emissions, particularly in stop-start traffic where MINI models spend much of their time. Whether you're navigating city streets in the MINI Cooper or covering longer journeys in the MINI Countryman, MHEV technology helps make every drive more efficient without compromising the fun-to-drive experience MINI is known for.
Browse our latest MINI MHEV models at Dick Lovett.
Land Rover Mild Hybrid Electric Vehicles
Land Rover has integrated mild hybrid technology deeply into its Ingenium engine family, across both petrol and diesel variants. The approach is consistent with everything Land Rover builds, pushing performance, capability, and comfort to new heights.
The MHEV system makes an already characterful and responsive engine feel sharper at low speeds, exactly where off-road driving demands the most from a powertrain. Not to mention the added efficiency, especially in models such as the Evoque, where city driving is so prevalent.
Browse our latest Land Rover MHEV models at Dick Lovett
Is a Mild Hybrid Right for You?
If the idea of electrification appeals but a plug-in hybrid feels like a bigger change than you want to make right now, mild hybrid technology is a natural step in that direction.
You will not need to plan charging stops. You will not need a wallbox at home. You will not need to think about the electric range. What you will get is a car that uses energy more intelligently, responds more eagerly, and costs a little less to run. All the benefits of electric motoring with none of the drawbacks.
For a broader look at how mild hybrids compare to full hybrids and PHEVs, visit our EV Hub. For tax implications and long-term cost-of-ownership comparisons, our EV Hub provides the full picture.
Speak with the team at your local Dick Lovett dealership to find your new MHEV.
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