The hybrid crutch by Nicol Louw
Hybrids are a compromised solution. Here’s why
HYBRID technology is not the future of powertrain development. There, I said it. Before you criticise my statement, however, let me put my case forward and, after hearing the facts, you can decide for yourself.
As an engineer, I love technical developments and can imagine working on a hybrid project must rate as one of the most interesting powertrain-engineering jobs out there. It must be fascinating to bring to fruition a complex control strategy that decides when to charge, when to run the internal-combustion engine (ICE) and when to boost acceleration with the electric motor. The problem is that the end result is still a highly compromised vehicle. Let me explain.
Internal-combustion engines excel at providing extended range and quick refuelling, but they are inef cient during stop/start driving. In contrast, electric powertrains are less complex, have excellent torque response and are very ef cient (even in congested driving). Their range, however, is unfortunately limited and “quick” charging still takes longer than a braai. Surely, then, a marriage between the two powertrains should be a match made in heaven?
Unfortunately not; any relationship built on a farce rarely lasts. The problem is in the fuel-ef ciency claims. We all know the European method of testing fuel economy (known as the NEDC procedure) is awed and yields unrealistic results. This is ampli ed when hybrids use electricity stored in the batteries (not fully accounted for) during the test cycle. This supplemental power runs out after the battery is depleted – something that will often happen in real-world driving – and, when running only on internal-combustion power, the hybrid’s meagre fuel economy climbs dramatically.
Our hybrid comparative test between the BMW 330e and Mercedes-benz C350e on page 74 is a perfect example. BMW claims 1,9 L/100 km in mixed use and Mercedes-benz 2,1 L/100 km. However, on our standard 100 km fuel route taking in city and country driving, both vehicles’ batteries drained completely and they spent the majority of the route propelled by their turbopetrol engines. Ultimately, the BMW returned an average gure of 5,0 L/100 km and the Benz an even higher 6,2. Those are nearly 300% worse than the claimed consumption.
Many governments around the world have accepted these claimed NEDC gures and have offered persuasive buying incentives for buyers of these “green” machines (although not ours), and this has kept manufacturers interested in producing them. Zero congestion charge (in London, for example), road tax and, in some cases, free parking are other fringe bene ts. Thankfully, a new realistic emissions and fuel-economy test method will soon be introduced (called the WLTP) and this will reveal the truth and is sure to send the powertrain couple to the divorce attorney.
In short, although the technology appears bene cial on paper, hybrids are just too complex. Compared with an ICE car of equivalent outputs, the hybrid version has roughly 500 extra part numbers for its additional hybrid components. It weighs several hundred kilograms more and, in South Africa, is between 20 and 30% more expensive than an equivalent ICE model in the same range. Boot space is also reduced due to the added batteries. Statistically, a more complex vehicle is less reliable; this is a fact of maths, not always a function of vehicle brand.
It’s likely that the ICE vehicle is only marginally slower to 100 km/h than its hybrid sibling, but consumes less fuel on longer journeys, where the electric motor rarely comes into play. The fact is that, if you optimise an ICE solution (petrol or diesel), it is as fuel ef cient as a hybrid while being lighter, less complex and cheaper.
This column’s title points to the fact that the technology does, however, help the automotive world move on to the next step of vehicle powertrains, which is fully electric. Imagine an electric Mercedes C350e (or BMW 330e) sans the fossil-fuel burner, which costs the same amount as a C250, has a range of 500 km, charges in ve minutes, can go from zero to 100 km/h in ve seconds and has running costs that are a quarter of the ICE alternative’s? RIP the internal-combustion engine…
Will we see this scenario become reality in our lifetimes? Surely, electric vehicles still have a long way to go to compete directly with ICE versions? Yes, but the gap is rapidly closing. If you turn to page 102, you’ll notice an all-electric supercar, the NIO EP9, has just obliterated the Nürburgring lap record for all production vehicles at 6:45,90, leaving many exotics sporting V8s and V12s in its wake (although we love their ICE sound while trying). Also note that the range for a Tesla Model S is already at 500 km, and the future suddenly looks a lot closer.
My advice is to stick to an ICE vehicle for now. Hybrids will soon be obsolete when the new generation of all-conquering electric vehicles arrives.