Have you ever seen a product, or series of products from a long list of vendors, that just seem to have things backwards and you can’t figure out why? This is exactly how I feel about hybrid electric cars… all of them (well, the production ones, anyway). As the name suggests, hybrids are a mix of traditional internal combustion engines, and modern electric motors. This marriage of old and new is meant to solve the “range anxiety” many people have with pure Electric Vehicles (EVs), while still offering a substantial benefit in terms of fuel economy and eco-friendliness. Unfortunately, more often than not though, a dive into the specifications will show that the manufacturers are prioritising small-capacity petrol engines as the primary motor for driving the wheels and relegating the electric motor to a limited range “boost” option. I believe this to be a rather strange choice, but it is one repeated over, and over again, by almost every hybrid car manufacturer. It’s quite odd to see this configuration win out over other more compelling options.
Before we look at alternatives, let’s take a closer look at the typical hybrid of today. With the exception of vehicles like the Chevy Volt – which ended production in February 2019, anyway – very few hybrids use the concept of running the electric motor as the primary, and using the internal combustion engine to charge the batteries as the secondary. In the case of the Volt, the car operates as a permanent electric vehicle that features a dual electric motor system capable of delivering up to 111 kW and an all-electric range of up to 85 km. Extending the range, and used only when the battery charge fell below a specific threshold, an additional 1.4L petrol engine (capable of 63 kW) was used. This configuration gave the Volt a fuel economy value of 2.2 L/100 km. That’s impressive, but I feel it could have been even better. In most hybrids, the situation is far less impressive, as they tend to use almost the opposite drivetrain configuration to the Volt, and prioritise rather asthmatic petrol engines that can merely leverage auto-start/stop technology to run all-electric for short periods of time. While this does improve the overall economy of the vehicle, it’s far from the optimal configuration, and doesn’t remove the dependence on fuel as much as some would like (especially for the price of hybrids).
Probably the strangest part about the hybrids that choose to prioritise internal combustion engines, is actually the fuel that they use: Petrol. It’s fairly well known, especially in places like Europe, that small diesels can be a whole lot of fun due to their torque at low revs (RPMs). It’s also fairly well known in the hybrid community, that that the electric system in most aren’t that capable, and the moment you breathe on the accelerator pedal the electric motor is replaced by the usually-terrible petrol engine. Surely, if fuel economy, emissions, and power are the priority, then what we should be seeing is more diesel hybrids. Additionally, consider the ongoing debate over whether it is better to choose a diesel over a hybrid: Doesn’t that raise the obvious idea of having a hybrid that uses a diesel motor instead? If the choice is between diesel and hybrid, then a diesel hybrid would surely tick all the boxes.
For many years, all manner of industry, and everything from datacentre backup power to earth-moving equipment at mine sites, have relied on diesel. As a fuel, diesel is less volatile than petrol and that makes the engines safer to operate; diesel motors operate are capable of producing the same power output as petrol motors, but at significantly less RPMs, load levels, and temperatures, which ultimately increase their reliability and durability; And due to the diesel fuel acting as a lubricant and coolant, combined with the lack of ignition system compared to a petrol engine, diesel motors are able to run for much longer periods under heavy load than petrol engines. Long story short, if you want to generate power, diesel is your friend. I get that some parts of the world aren’t used to diesel engines, and can’t shake the image of these being loud, smoke-blowing, tractors from 1964. But, for the rest of the world, combining the awesome range and torque of diesels, and adding more performance via a electric motor, can only mean great things for the future of hybrids.
But hybrid manufacturers shouldn’t just replace petrol engines with diesel engines: Plenty of automakers have looked at using diesels in their hybrids. But most of these want to use the diesel motor as the primary that turns the wheels, and boost that with electric… and that’s the entirely wrong way around. The key is to create an electric-first hybrid, and use a small, efficient, quiet, low-emission diesel as a generator to charge the batteries when needed.
Personally, I’d love to see Hydrogen Fuel Cell vehicles hit the market. No, not the “scary” and “inefficient” hydrogen gas-powered things that deliver worse economy than LPG-powered vehicles, but the proper salt-water-to-electricity systems, like in GM’s Hywire concept (which works well, but never entered production) from 2002. Sure, some manufacturers – notable BMW – are heading this way, but it has already been 18 years since we had indisputable proof of this working, and we’re still focusing on inefficient hybrids and pure EVs. Sure, Hydrogen Fuel Cell vehicles aren’t here yet, and are likely to be far more costly than pure EVs in the near term, but I still have hope. Until then, dear car manufacturers, please consider switching up the hybrid recipe so that we can enjoy the performance of an electric-first car, with the anxiety-reducing benefit of a diesel generator tucked away inside.