As the UK edges closer to a ban on the sale of new internal combustion engine (ICE) vehicles, car manufacturers are making the most of the time that remains. Rather than being left behind, the ICE is undergoing its most significant transformation in years – a focused final push to make traditional engines cleaner, smarter and more efficient than ever before.
While the long-term outcome may be zero-emission vehicles (ZEVs), getting there will depend on a combination of hybrid technology, advanced engineering, and low-carbon fuels. Drivers will see ICEs working alongside electric motors in hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs). These systems allow the engine to operate within its most efficient range while using electric power at lower speeds or in stop-start traffic. The result is lower fuel consumption and fewer emissions, without the need for full electrification.
Efficiency has become the focal point of ICE development. Engineers are using a wide range of innovations to reduce waste and maximise output. Technologies such as direct fuel injection, turbocharging, and variable valve timing are now standard, helping smaller engines deliver the power of much larger units from previous generations. Engines are now designed to switch off some cylinders when full power isn’t needed, reduce friction with specially coated parts, and manage heat more efficiently – all helping to improve fuel economy and reduce harmful emissions.
At the same time, the fuels powering these engines are changing. Manufacturers are working to adapt ICEs to run on alternative fuels such as biodiesel, renewable diesel, and hydrogen. These fuels, if certified as low or zero carbon, could allow ICE vehicles to remain part of the new transport mix even after sales bans come into force. Synthetic fuels, produced using captured carbon and renewable electricity, are also being explored as a route to carbon neutrality using existing engine platforms and infrastructure.
Artificial intelligence (AI) and simulation tools are now widely used in engine development, allowing engineers to test thousands of different operating conditions without needing to build physical prototypes. This speeds up innovation and makes sure engines are optimised for real-world performance, not just laboratory conditions. Increasingly, software and control systems are becoming as important to ICE performance as the mechanical components themselves.
Despite all this progress, the end of the ICE as a new-vehicle technology is in sight. Across Europe, countries are introducing legislation aimed at achieving net-zero emissions. In the UK, the sale of new petrol and diesel cars is expected to end by 2035, with earlier targets being considered. The pressure on manufacturers to comply with future emissions regulations while meeting current market demands has never been higher.
Yet the end of the ICE story is about refinement and adaptation. Manufacturers are not simply trying to extend the life of fossil fuel engines – they are re-engineering them to support wider environmental goals. These engines, paired with hybrid systems or running on sustainable fuels, are helping to reduce emissions today while the infrastructure and technology for full electrification continue to develop.
When it arrives, the last generation of ICE-powered vehicles will likely be the most advanced ever built. In the years leading up to the ban, the internal combustion engine may still have relevance in a changing world.