INSTANT EXPERT
With drivetrains evolving so rapidly, considering a replacement car has never been more confusing, leading Rob Marshall to find out what hybrids are all about.
Despite the misinformation surrounding them, Electric Vehicles (or Battery Electric Vehicles/BEVs, to give their official title) are mar vels. This relates not just to the drivetrain technology but also to the attention that manufacturers have given to safety, considering the lethal voltages that they employ.
Yet, in the real world, the BEV is coming out of its honeymoon period. New sales are driven mainly by corporate tax incentives and private sales growth appears to be stagnating. Even if relatively early devotees can work their lives around the range anxiety and lack of public chargers, they are not immune to the market forces, which have been savaging the BEV withcrippling depreciation, compared with its fossil-fuelled counterparts.
Despite governments being fixated with an all-electric future, some car manufacturers admit that most UK drivers are at least one trade-in away from going fully electric. On the used car scene, diesel remains a very realistic proposition, especially if you cover high mileages and spend most of your time out of urban areas. Yet, modern petrol engines are worth considering, especially as electrified hybrid models can deliver impressivereal-world fuel economy figures but without the complex and expensive to repair emissions control equipment.
What is a ‘Hybrid’?
Hybrids are electrified vehicles that possess combustion engines. The problem is that there are many types of hybrid vehicles and carmaker marketing departments have made the term virtually all-encompassing.
Even so, almost all hybrids fit into two simple categories: Low-voltage hybrids, which cannot be driven under electric-only power, and high-voltage hybrids, which can.
Low-Voltage (‘Mild’) Hybrids
Mild Hybrid Electric Vehicles (MHEV) are the simplest types that you will encounter. They are also surprisingly DIY-friendly. They employ electricity to hot start and assist the engine, using a combined starter-alternator (known formally as a BISG – Belt Integrated Starter Generator), mounted to the Front End Auxiliary Drive (FEAD) belt. Dependent on the car, the alternator function recharges not just the lead-acid battery but also the lithium-ionpower pack that may also be fitted. To ensure a smoother and virtually silent experience, the BISG starter function is used, when the engine is restarted in Start-Stop mode. A conventional 12-volt starter motor tends to be fitted as well, for cold starting purposes.
