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Diesel v hybrid: Which is best for me?

  • We take a look at the pros and cons of buying a hybrid car
  • Is now the time to make the switch?
  • How do hybrids stack up against diesel power?

Written by Keith Adams Updated: 4 April 2023

The technology used in hybrid cars has been around since 2000 in the UK, however you wouldn’t be alone if you’d never driven one. Although small sale volumes initially caused many to doubt the new technology, there are significant benefits to choosing a hybrid as your next new car and momentum is building.

The main question, of course, is what type of hybrid car should you look at buying. In reality, mild-hybrid cars aren’t really going to make a massive difference as they generally can’t run on battery power alone, and the motors contained within are just there to assist with your running. In short, consider them to be just slightly more efficient petrols and diesels, rather than hybrids in their own right.

Self-charging and plug-in hybrid cars, however, are more useful. A good example of the former is something like the our 2023 Car of The Year, the Honda Civic, which constantly uses the battery to make the most of the engine and motor combination. It manages to deliver 60mpg plus and excellent performance. The best plug-in hybrids go a step further, with larger batteries that you can top-up, and the potential to go more than 20 miles without using the engine at all.

So, is now the time to consider buying a hybrid car, or is diesel the better choice? Here we take a closer look at the pros and cons for both.   

How do hybrid cars work?

If you’re looking for zero tailpipe emissions found in electric cars but don’t want to be restricted on how many miles you can travel, a hybrid car – in theory – offers the best of both worlds. These days, they tend to be called self-charging hybrids, denoting that they don’t need to be plugged in.

Hybrid cars essentially combine an electric motor with a combustion engine (usually petrol). Conventional hybrid cars uses the electric motor to supplement the engine for improved acceleration, while regenerative braking helps charge the batteries – such as the Toyota Corolla and the aforementioned Honda Civic.

Although offering lower running costs and emissions than most diesels, conventional hybrids can only be driven for a short amount of time on electric power alone.

A plug-in hybrid offers battery-powered, silent city running.

What is a plug-in hybrid?

Plug-in hybrids (or PHEVs) are different. They can be charged at the mains and have an indicated range where the car can be driven on electric power, significantly more than the conventional hybrids mentioned above – examples include the BMW 330e and Vauxhall Astra GSe which are both also offered in hybrid estate form. There’s also a raft of hybrid SUVs to consider – with the choice growing quickly.

You can typically charge them up at home, and a domestic wallbox should have a hybrid car battery topped up in about four to six hours. Most public chargers will also accommodate PHEVs, although only a handful will accept the best rapid chargers. Generally, once the battery is depleted, it will behave like a self-charging hybrid, and there can be some drop-off in performance.

Is hybrid right for you?

Hybrids are at their best when being driven in town. Plug-ins especially suit city life as they have a lot more capability to be driven solely on electric power. When the speed climbs above a certain level or the battery begins to run out of energy, the car automatically switches to the conventional engine to power the wheels and charge the batteries.

What’s the VED car tax on hybrid cars?

Hybrids offer both lower tax costs and running cost improvements. Legislation is only going to get tighter. The congestion charge costs £15 per day, and there is the ULEZ – Ultra Low Emission Zone – which operates in the same area as the congestion charge, and requires drivers of cars not meeting the emissions standards to pay an additional £12.50 per day. For more information about London’s congestion and emissions charges, visit the tfl.gov.uk website

There’s also the fuel savings – which potentially could cost you much less if you charge overnight at home. One of the perks to driving on electric power is that you’ve got 100% of the car’s torque from zero revs, meaning instant reaction when you push the accelerator. There’s also very little engine noise to be heard.  

It’s important to make sure a hybrid fits into your lifestyle. If most of your journeys involve long motorway distances it’s unlikely you’ll see the cost advantages mentioned above. If you buy a plug-in, remember that you’ll need to allow a fair few hours for charging each day if you’re planning on making the most of the battery power.

BMW 330e - best plug-in hybrid

How much do hybrid cars cost to buy?

There’s also the higher purchase price or monthly payment to consider. A hybrid is almost always going to cost more than a comparable diesel – some as much as 20% more – so you’ll need to travel a lot of miles and run your hybrid for a number of years to recoup the extra cost.

Hybrid cars – the pros

  • Lower tax bills
  • Most are congestion charge free
  • Lower costs when driven on electric power

Hybrid cars – the cons

  • Expensive to buy or finance
  • Charging times
  • Limited electric range copared with EVs

Should I get a diesel car instead of a hybrid?

Today’s diesel engines are a far cry from the dirty, clattery powertrains of old and not only are they more refined, they’re more economical too. One of the big draws to diesel engines is the fuel economy they offer and although not as impressive as hybrid on paper, if you’re planning on driving mainly long motorway journeys, diesel will in most cases be the more economical choice.   

In comparison to hybrids, diesels are almost always the cheaper choice to buy too – but there’s fuel to consider and higher tax bills to factor into your costs. It’s also commonly accepted that diesel cars aren’t normally as quiet to drive as petrol or hybrid cars, although at speed there’s almost nothing in it.

Diesel cars: the pros

  • Cheaper to buy than hybrids
  • Known residual values
  • Refuelling takes minutes instead of hours recharging batteries

Diesel cars: the cons

  • Fuel costs
  • Higher tax bills
  • May not be as nice to drive