Hybrid vs Mild Hybrid vs Plug-In Hybrid: Which Is Best Used

Understanding Hybrid Vehicles

The automotive landscape has evolved significantly in recent years, with hybrid vehicles becoming increasingly popular among UK drivers. They offer a blend of traditional combustion engines and electric power, aiming to provide better fuel efficiency and lower emissions. However, not all hybrids are created equal. There are three main types: hybrid, mild hybrid, and plug-in hybrid. Each has its own unique characteristics, advantages, and disadvantages. This guide will delve into these differences, helping you make an informed decision when considering a used vehicle.

What is a Hybrid Vehicle?

A hybrid vehicle combines a conventional internal combustion engine (ICE) with an electric motor. The electric motor is powered by a battery that is charged through regenerative braking and the ICE itself. This setup allows the vehicle to switch between the two power sources, optimising fuel efficiency and reducing emissions. Common examples include the Toyota Prius and the Honda Insight.

When driving a hybrid, you might find that the electric motor assists the engine during acceleration, or it may even power the vehicle at low speeds. This can lead to significant fuel savings, especially in urban driving conditions where stop-and-go traffic is common. However, the battery size in traditional hybrids is relatively small, meaning they typically cannot operate solely on electric power for extended periods.

What is a Mild Hybrid?

Mild hybrids are a step down from traditional hybrids. They still feature an electric motor and battery, but the electric motor cannot power the vehicle on its own. Instead, it assists the ICE, particularly during acceleration, and helps improve fuel efficiency. This is often achieved through a technology called Integrated Starter Generator (ISG), which can restart the engine quickly and smoothly when needed.

Mild hybrids are generally less complex and lighter than full hybrids, which can lead to lower costs and potentially better reliability. However, they do not offer the same level of fuel savings or emissions reductions as traditional hybrids. Examples of mild hybrids include the Ford Fiesta EcoBoost Hybrid and the Audi A6 55 TFSI e.

If you are weighing up alternatives, our guide to MG4 Used Buying Guide covers similar ground from a different angle.

What is a Plug-In Hybrid?

Plug-in hybrids (PHEVs) take the hybrid concept a step further. They feature larger batteries that can be charged from an external power source, such as a home charging point or public charging station. This allows PHEVs to operate on electric power alone for longer distances, typically between 20 to 50 miles, depending on the model.

The ability to plug in and charge means that PHEVs can significantly reduce fuel consumption for drivers who primarily make short trips and can charge their vehicles regularly. When the battery runs low, the vehicle seamlessly switches to the ICE. Popular examples of plug-in hybrids include the Mitsubishi Outlander PHEV and the BMW 330e.

Comparing Efficiency and Performance

When considering efficiency, it’s essential to look at how each type of hybrid performs in real-world scenarios. Traditional hybrids tend to excel in urban environments, where their ability to switch between electric and petrol power can lead to impressive fuel economy figures. For instance, a Toyota Prius can achieve around 60 mpg in city driving conditions.

Mild hybrids, while they offer some improvements in fuel efficiency, typically fall short of the figures achieved by full hybrids. They are best suited for drivers who want a slight boost in efficiency without the complexities of a full hybrid system. A mild hybrid like the Ford Fiesta EcoBoost Hybrid might achieve around 50 mpg, which is decent but not as impressive as its hybrid counterparts.

For more on this topic, take a look at our EV Battery Degradation Explained guide.

Plug-in hybrids shine when it comes to electric-only driving. If you can charge your vehicle regularly, you may find that you can complete most of your daily driving without using any petrol at all. This can lead to significant savings, especially if you can take advantage of off-peak electricity rates. However, if you regularly exceed the electric range, you may find that fuel consumption can become less efficient than a traditional hybrid.

Battery Health and Maintenance Considerations

One of the most critical aspects of owning any hybrid vehicle is understanding battery health. Batteries in hybrid and plug-in hybrid vehicles can degrade over time, affecting performance and efficiency. When purchasing a used hybrid, it’s essential to check the battery's condition and remaining capacity.

For traditional hybrids, the battery is generally designed to last for the lifetime of the vehicle, but it’s still wise to check for any signs of degradation. You can do this by looking at the vehicle's service history and checking for any battery replacement records. Many manufacturers offer warranties on hybrid batteries that can last up to 8 years or 100,000 miles, so knowing the warranty status can be beneficial.

In the case of plug-in hybrids, the larger battery means that there’s more to consider. If you’re looking at a used plug-in hybrid, make sure to check the battery health thoroughly. Some models, like the used BMW i3, have specific battery health reports available, which can provide insight into how well the battery has been maintained.

You might also find our Used Kia EV6 Buying Guide UK guide useful alongside this one.

Charging Costs and Infrastructure

Charging costs and infrastructure are vital considerations when deciding between hybrid, mild hybrid, and plug-in hybrid vehicles. Traditional hybrids do not require any charging infrastructure, as they rely solely on petrol. However, if you opt for a plug-in hybrid, you’ll need to consider how and where you will charge the vehicle.

Charging at home is often the most convenient option. Installing a home charging point can cost between £800 and £1,500, depending on the installation requirements. Public charging stations are also becoming increasingly common, but you may encounter varying costs depending on the provider. Some public charging points offer free charging, while others may charge per kWh.

For example, the used Renault Zoe is a popular choice among plug-in hybrid drivers due to its extensive charging network and affordability. It’s essential to factor in these costs when calculating the overall running costs of a plug-in hybrid compared to a traditional hybrid.

Common Problems to Watch For

Every vehicle type comes with its own set of potential issues, and hybrids are no exception. Traditional hybrids may experience problems related to the battery or electric motor, while mild hybrids can face issues with the ISG system. Plug-in hybrids may encounter complications related to their larger batteries and charging systems.

We have covered related ground in our Ford Mustang Mach-E Used Buying Guide UK guide, which is worth reading if this subject interests you.

When considering a used hybrid, it’s wise to research common problems associated with specific models. For instance, the used BMW i3 has been noted for its battery management system, which can sometimes malfunction. Additionally, always check the vehicle's MOT history on the GOV.UK MOT history site to ensure there are no red flags.

Running Cost Savings Compared to Petrol/Diesel

One of the most appealing aspects of hybrid vehicles is the potential for savings on running costs compared to traditional petrol or diesel vehicles. The savings can vary significantly based on driving habits, fuel prices, and the specific model chosen.

For example, a traditional hybrid like the Toyota Prius can achieve around 60 mpg, while a comparable petrol vehicle might only manage around 40 mpg. This difference can translate into substantial savings over time, especially for drivers who cover significant mileage.

Plug-in hybrids can offer even more savings if you can charge regularly and drive within the electric range. If you can complete your daily commute using electric power, you may find that your fuel costs drop dramatically. However, it’s essential to consider the initial purchase price of a plug-in hybrid, which can be higher than that of a traditional hybrid or petrol vehicle.

If things go wrong after purchase, Citizens Advice can help you understand your legal rights.

Dave's Verdict: Is It Worth Going Electric?

In conclusion, the decision between hybrid, mild hybrid, and plug-in hybrid vehicles ultimately depends on your driving habits, budget, and preferences. Traditional hybrids are excellent for those who want improved fuel efficiency without the need for charging infrastructure. Mild hybrids offer a simpler, more cost-effective option but may not provide the same level of savings.

Plug-in hybrids are ideal for drivers who can charge regularly and want to maximise their electric driving experience. However, they come with additional considerations regarding battery health and charging infrastructure.

Before making a decision, consider checking any electric car with Dave's free vehicle intelligence report to ensure you’re making a well-informed choice. By understanding the differences between these hybrid types, you can find the vehicle that best suits your needs and lifestyle, ultimately leading to a more satisfying and economical driving experience.

Whether you’re leaning towards a traditional hybrid, a mild hybrid, or a plug-in hybrid, the key is to do your research and ensure that the vehicle you choose aligns with your driving habits and budget. Happy car hunting!