What is MHEV?
The term MHEV refers to Mild Hybrid Electric Vehicles
Mild Hybrid Electric Vehicles are some times also called:
- Power Assist Hybrids
- Battery Assisted Hybrid Electric Vehicles (BAHV)
From the outside, these cars seem almost identical to a fully hybrid vehicle. But when you dive into the technical specifications, you’ll realize that MHEVs are designed to improve on the disadvantages of fully hybrid vehicles.
We have written a comprehensive guide to PHEV here.
We also have a comparison of PHEV and MHEV here.
History of MHEV
Surprisingly, the concept of electric vehicles was in circulation as early as the 1900s[1].
Ford experimented with electricity in its Model T, which ended up as a prototype.
In the late 1970s, Volkswagen made the VW Taxi which had gasoline plus an electric motor, in order to deal with the oil crisis.
Prototypes of hybrid cars, mild hybrids and electric cars have been made all through the history of electric vehicles.
In the year 1828, Anyos Jedlik created a small prototype car powered by an electric motor. The model didn’t make it to the mass market as it was not designed to be a commercially viable vehicle.
Later in 1839, the Scottish inventor Robert Anderson came up with a larger electric motor that could actually power a large carriage.
During the same period, somewhere in 1835, Thomas Davenport invented batteries that had the power needed to drive the car around. The only issue was the batteries were non-rechargeable.
As you can imagine, the lack of recharging capabilities (plus the car’s short mile range) made the Davenport car challenging for the purpose of road trips.
Based on historical data, the first practical electrical/hybrid car was created by William Morrison.
Throughout this early history, the big issue for MHEVs was they provided alower mile range than gas-powered vehicles. This was a roadblock to the mass production of MHEVs, especially on the scale of gasoline-powered cars.
Besides the mile range issue, automobile manufacturers have had to overcome a large number of other practical hurdles before electric vehicles could be widely adopted. Slowly with time, there has been wider and wider acceptance of these electric vehicles among the public.
The concept of PHEV (Plug-in Hybrid Electric Vehicle), MHEV, and other hybrid variants is fairly recent.
This development takes us one step further in the story of electric cars becoming a primary transport choice.
It was in 1884 that the first truly electric/battery-operated car came into operation. It was invited by Thomas Parker in Britain. This car was not at all ready to be used on commercial roads, due to the poor quality of roads and rash traffic conditions found around the world. Instead, it began to be predominantly used inside airports, hospitals, and golf courses to cover short distances.
in 1914, the famous inventor Thomas Edison played a crucial role in making electric cars more feasible. He developed more powerful batteries that helped expand the range of electric cars. He worked closely with Henry Ford who owned one of the biggest automobile brands in the world. The association paved the way for some big innovations in a time when gasoline cars [1] had not yet been adopted widely. The vehicles were decades away from being powerful beasts like a Lamborghini or Ferrari as in modern times.
The gasoline car cost $650 while an electric vehicle in the 1900s went up to $1750 and it ended innovation in electric vehicles until the 1970s when the world was finally staring at oil depletion.
In the past few decades, from the 1990s to the 2020s, electric cars, hybrid cars, and mild hybrid electric vehicles have co-existed trying to compliment the space created by the fact that oil resources will soon be depleted in the world and it was time to adopt the alternate technologies one step at a time.
The primary goal was to make cars that can be charged and driven on the road, not only to commute to office in city traffic but also for long drives to reach nearby cities and anywhere one would travel on a gasoline or diesel vehicle.
The road, however, was not as straightforward as it sounds, which led to the evolution of MHEVs and PHEVs.
Hybrid vehicles have both an electric motor and a car engine whereas mild hybrids try to set a new benchmark.
The biggest companies, such as General Motors released their Parallel Hybrid Truck whereas Honda brought in hybrid variants of Honda Civic, Jazz, and Accord models.
According to a poll conducted by the National Automobile Show in New York City, the majority of automobile enthusiasts preferred electric vehicles.
The concept of using batteries for cars sounded feasible when compared to inventing an engine that would provide the horsepower necessary to drag large vehicles on the road.
The popular manufacturer known for their MHEV cars is Audi. A significant surge is definitely around the corner for electric vehicles and the same will reflect on both hybrid as well as mild hybrid cars, SUVs, and trucks.
The advantages that they deliver especially with the successful 48V MHEV architecture is expected to provide the much-needed boost to make them widely adopted. When the market share for electric vehicles increases, the MHEVs, despite having very minor space in history, are expected to sell nearly 25 million units by 2030 according to a survey by Continental.
The choice of car models available is also expanding at a rapid pace which is a necessity for buyers to finally look into MHEVs as much as they do in PHEVs and fully-electric vehicles
MHEV Cars
An MHEV car is usually less expensive when compared to a fully hybrid vehicle, has fewer components to worry about and is more like a gasoline-powered vehicle but with better fuel savings.
Here is a video from Land Rover about MHEVs :
Popular MHEV Models
- Audi A8 Le-tron
- Honda CR-Z
- 2018 Buick LaCrosse
- Honda Insight
Let us look at these vehicles in more detail next.
Audi A8 Le-tron
The Audi A8 is a mild hybrid electric vehicle and perfectly delivers a fine balance with its V6 turbo engines and the electric motor mounted in it. The model was released in 2018 and features all the latest innovations including a touchscreen to control its functions.
The company is also planning to upgrade it with garage and parking pilot features to make it more autonomous.
It is powered by a lithium-ion battery that can comfortably deliver at least 31 miles of coverage before it switches back to the gasoline engine.
The company makes use of their new MHEV technology driven by a 12-volt setup and the smaller lithium-ion battery is placed in the luggage compartment to provide increased legroom.
Honda CR-Z
Designed to be a sport hybrid coupe, the Honda CR-Z delivers a stylish look combined with a 2×2 seater.
Honda continues to innovate in the field of mild hybrid vehicles and hybrid vehicles since the year 2000 with multiple models. The CR-Z is one such edition which is on par with the Honda Insight and the Civic Hybrid variant.
However, the model’s production ended in 2016 but it is expected to be revived with a whole new model number for the next few years to come.
General Motors eAssist Cars
2018 Buick LaCrosse
GM continues to innovate every year with a whole lot of models and all their cars that are categorized with eAssist can be considered MHEVs.
The 2018 Buick LaCrosse uses eAssist hybrid technology and being a sedan, it comfortably falls in the MHEV cars list.
The car has a very conventional design that ensures it doesn’t give any hybrid EV vibe, allowing users to ride it anywhere as they would with a conventional car. It is powered by a 24-cell 0.5kWh lithium-ion battery and uses a regenerative braking system to generate additional power while on the move.
Honda Insight
Honda Insight has a pretty long history as it was originally launched way back in 1999 and later found its way into the market in 2009. There have been multiple iterations and the latest version available is the 2020 four-door sedan with mild hybrid electric features. The model is designed to be visually appealing as Honda revealed in a new advertisement and is also going to compete against fully hybrid variants such as the Toyota Prius and Hyundai Ioniq.
While the previous iterations of the Honda Insight were mild hybrid electric vehicles with smaller batteries, it is to be seen how the 2020 models go through. The company may choose to make fully hybrid and MHEV cars or stick to only one model that does better sales against its tough competitors like the Prius.
MHEV SUV
MHEV SUV
Finding an MHEV SUV that makes use of the technology to deliver excellent power with a gasoline engine coupled with better fuel efficiency is much easier than an MHEV car. That is, there are more MHEV SUVs on the market than MHEV cars.
The accolades go to General Motors as the company under their eAssist system released a couple of vehicles in the past decade that fall under the SUV category.
2017 Silverado 1500
In the past, the eAssist, which indirectly refers to a mild hybrid electric vehicle, was referred to as the Belt Assist System by General Motors. The Silverado 1500 is one of their newest models that delivers an excellent mild-hybrid experience. There is a strong catch when it comes to powering SUVs that are usually large vehicles with an electric motor and battery.
The Silverado 1500 is powered by a 5.3-liter V8 engine while it’s electric motor delivers 13 horsepower. It does require assistance from the car’s gasoline engine as the electric motor will not be able to completely drive such a large vehicle. The lithium-ion battery makes use of regenerative braking in order to generate additional power and delivers a hybrid-like SUV experience.
Range Rover Evoque
Opting for the Range Rover Evoque will help you contribute to the planet with a lower emission rate, reduce fuel usage and also boost the overall performance of the SUV.
The company specializes in making the best SUVs and this is an MHEV SUV that is ideal to cruise through congested city traffic.
Regenerative braking system allows it to generate electric power every time you brake, coast or keep the car static.
Here are a couple of unique features and advantages of the Range Rover Evoque:
- Emission control up to 8g/km of CO2.
- Automatically shuts down the engine when cruising at 17km/h
- Delivers 140Nm of electric torque.
Discovery Sport MHEV Edition
Land Rover from Jaguar offered buyers more options and the MHEV edition of their popular Discovery Sport is a great addition to their line-up.
The particular model is powered by a 48-volt powertrain which is a mild variant that considerably contributes to better fuel management and makes use of all the popular hybrid features.
Similar to other models, the Sport edition shuts off the engine at lower speeds and reduces CO2 emissions besides being powered by an RDE2 certified engine.
The MHEV model will be available in both gasoline engine variant and diesel engine models, providing buyers enough options to choose from if they are planning to go all-hybrid with their next SUV.
Audi Q7 SUV
The Audi Q7 is a perfect MHEV powered by a 48V mild-hybrid system and provides a minor yet effective fuel efficiency level for its users.
According to the official claim, the SUV can help reduce 0.7-liters of fuel savings for a 100-kilometer drive and every time you brake, the BAS generates about 8kW of power.
The excessive power is stored in the battery and automatically utilized whenever you drive the vehicle at lower speeds. It can also automatically switch off the engine when the car is coasting at approximately 35 mph up to 99 mph to save energy.
Technology of MHEV
The technology that is being used in a mild hybrid electric vehicle may sound difficult to understand for the average user.
While keeping things simple, an easier way to comprehend it is that MHEVs are much closer to a conventional gasoline-powered vehicle and they are not as superior or advanced as a hybrid electric car.
Audi Explains MHEV technology in the video:
The hybrid electric cars are equipped with a dedicated gasoline engine and electric motors that allow the vehicles to be driven using either power source.
However, the concept of using MHEV technology is to allow a car or wagon to significantly rely on the power generated by the gasoline engine whereas power savings will be achieved with the help of regenerative braking which will help power up the battery and the electric motor.
What Drives an MHEV?
The electric motor used in an MHEV is not designed to individually propel it without assistance from a gasoline-powered conventional engine.
They are rather utilized to act as a power booster that helps save power, propel the car at varying speeds and also act as a way to improve the overall efficiency of the conventional engines used in vehicles.
Based on different surveys, a mild hybrid vehicle can approximately save about 10 to 15 percent in fuel efficiency when compared with a car that has no type of hybrid technology installed in it.
In order to better understand the technology behind these cars, you can consider the Audio A8 MHEV with an active suspension as an example.
In this particular model, the car is powered by dual V6 turbo engines which ensure maximum torque and acceleration for the Audi A8. At the same time, as they fall under the mild hybrid category with the necessary components, they can help reduce fuel consumption to a certain level. Users can save 0.7 liters or 0.3 gallons in U.S. metrics of gas when driving for 62.1 miles or 100 kilometers.
In the long run, the savings will be significant, which is the primary reason buyers opt for MHEV models.
Behind the Technology
The Volkswagen MHEV cars are another prominent examples of how MEHV technology is implemented in everyday cars and bring about significant savings in being fuel-efficient.
The Volkswagen models are equipped with a 48V belt starter generator and provide savings up to 0.4 liters of gasoline on an average of 100 kilometers. When these vehicles are used as your primary source of commuting, they can help you save significant money spent on fuel on a daily basis.
Volkswagen Golf 8 is one of the models that fall into the MHEV category and comprises of multiple components including:
- A starter motor
- A 12V battery
- DC/DC converter
- 48V lithium-ion battery
- 48V starter belt generator.
While the type of battery used and their role in helping a hybrid engine work will be discussed in a different section, all these components work together in order to achieve results and deliver impressive fuel efficiency.
The major advantage of an MHEV model is its ability to sustain powerful acceleration and top speed as it is still handled by the conventional V6 or other engines used by the manufacturer.
The hybrid part is mildly incorporated and saves fuel when possible through freewheeling, regenerative braking and other modes.
MHEV Battery
The future is filled with expectations about a fully battery-powered car that runs without using gasoline or diesel as its primary fuel.
However, the first step into the world of hybrids starts with MHEV variants and they are prevalent. They already help car owners save fuel by using minor but effective methodologies in place.
In order to better understand the MHEV battery, its size and how it works, we can take a look at a couple of popular mild electric cars available in the market and the technology that powers them on the inside.
The Land Rover is a popular brand that makes the best SUVs in the world and their Range Rover Evoque MHEV is a hybrid vehicle capable of delivering impressive performance while being fuel-efficient.
Battery Size and Use Case Scenario
The size of the battery found in the Range Rover Evoque is a 48V. Industry-standard is essential for all manufacturers to follow a widely accepted size and the 48V electric motor battery is widely accepted by major car companies.
Marketed as a mild hybrid, the Evoque reduces CO2 emissions by a significant number and ensures that the overall smoothness and driving experience is not compromised by any means when the car drifts or uses a regenerative braking system.
On a similar note, the Audio A8 mild hybrid electric vehicle utilizes multiple technologies and has two different batteries in place.
One of them is a powerful and much bigger lithium-ion battery that is integrated inside the luggage compartment whereas the 48-volt electrical system receives its power from a belt alternator starter. Based on the press release information provided by these manufacturers, the 48V lithium-ion battery is split into 14 x 8Ah lithium-ion pouches. The setup allows these batteries to deliver a maximum power of 200Wh and the fuel efficiency will vary based on the size and the type of vehicle that is powered by this mild hybrid battery setup.
The Volkswagen Golf 8 is equipped with a 48V lithium-ion battery and the car falls under the mild hybrid electric vehicle category.
The setup also includes a 12V battery that is utilized to power the starter motor and other components that support the battery including a DC-DC converter and a 48V starter belt generator. The batteries found in an MHEV play a huge role in generating power, storing it and using it whenever possible in order to make the vehicle more fuel-efficient than an ordinary gasoline car.
The Role of MHEV Battery
When directly compared with a full hybrid vehicle that has all the space required to mount as large a battery as possible, mild hybrid vehicles save that space for the conventional car engine.
The spacing is quite limited in all types of vehicles that are much less hybrid than a proper hybrid vehicle.
Despite all these shortcomings, the size of the battery and the power delivered is phenomenal because it helps save fuel while occupying very little space in the vehicle.
The battery and the engine, when paired with one another in the right size, lead to fuel-saving measures such as regenerative braking similar to how a hybrid car handles it but with much fewer components to work with.
MHEV Engine
Mild Hybrid vehicles are identified with different naming schemes in the automobile market.
They are also widely known as battery-assisted hybrids and power-assist hybrids as they provide additional torque for the conventional gasoline-powered engine.
Most MHEV cars from major manufacturers typically use a 48V MHEV system which comprises four main components.
All these hybrid vehicles will have an electric machine which makes use of TiMG or BiSG technology.
Furthermore, it is supported by:
- an inverter
- a DC-DC converter
- a 48V volt battery.
Some models also have an additional 12V battery which is used to kickstart the 48-volt belt start generator.
Some of the common examples of car models that use this engine and battery setup are Volkswagen Golf and Audi A8.
Every year, automobile manufacturers spend a significant amount of money and time in developing mild hybrid technology which is the key to bringing full hybrid vehicles into the mainstream market. A dedicated team of automobile brands like Tesla does exist and such companies focus on real electric cars.
However, the evolution and presence of MHEVs, PHEVs, and full hybrid vehicles play a significant role in making cars more fuel-efficient for the average user around the globe.
Evolution and Improvements in MHEV Engine Setup
Ford is a prominent name in the automobile industry and the brand was one of the pioneers to have entered the manufacturing sector.
In their latest upgrade, they launched a 1-liter EcoBoost engine powered by an 11.5kW belt-driven MHEV engine.
It uses the BiSG technology that stands for belt-driven motor power and this particular setup is responsible for saving and storing the power generated every time the user brakes the car where excess energy is lost in transition.
The BiSG setup works in unison with a three-cylinder engine that acts as a booster to improve the overall acceleration and driving experience.
In theory, the Ford car is capable of delivering 50Nm additional torque when compared with a conventional gasoline-powered vehicle of the same model.
In a typical setup, the engine used in Mild Hybrid vehicles may not be ideally used in fully hybrid vehicles. The engine is more of a motor setup driven by a smaller battery and they are not capable of operating on their own.
The type of electric motor used in a hybrid vehicle is powered by a much larger battery, thus allowing these vehicles to run for miles without relying on the motor engine.
Compared to the mild hybrid or MHEV models such as the Toyota Crown released in 2002, the newer innovative models are much more fuel-efficient and can help in significant savings in fuel costs when used on a regular basis.
A couple of new models powered by MHEV engines are scheduled for launch in the near future such as the Mazda CX-5, Mercedes AMG variants, and Range Rover covers. All these cars, be it sedans or SUVs, will rely on the BiSG technology and in some cases will utilize TiMG wherever possible in order to achieve the hybrid status that buyers are willing to adopt in this generation.
Mild Hybrid Electric Vehicle