Lexus RC 300h MPG & CO2 emissions

The Lexus RC 300h is a 'self-charging' hybrid, so there’s no need to plug it in. But its economy and emissions figures are nothing special

MPG (comb) MPG (extra high) MPG (medium) CO2
45.5mpg N/a N/a 114g/km

Lexus is quite rare in the UK market, as it doesn’t have any diesel engines in its line-up. As a result, its most economical models are its hybrid cars, which are what the company calls self-charging hybrids.

That means that, while they combine a petrol engine with a battery-driven electric motor, the battery is quite small. So, the car can’t go all that far on electric power – certainly not as far as a plug-in hybrid – and that means that its overall economy isn’t that great.

Lexus claims the RC 300h will achieve 45.5mpg, emitting 114g/km of CO2 – not bad for a car of this size and weight. However, while there are no hybrid models in the line-ups of rivals such as the Audi A5, BMW 4 Series and Mercedes C-Class, it’s worth noting that several of the diesel-engined versions can match – and, in some cases, beat – the RC for economy.

Lexus RC MPG & CO2 emissions

As with all self-charging hybrids, the RC’s range on electric power alone is minimal – only a mile or so. It comes into its around town, where it crawls through traffic without any need to enlist the help of the 2.5-litre four-cylinder petrol engine. And, if you want, at the press of a button, you can engage EV mode, which means the car will run on electric power as much as it can.

All the time the car is running, any excess power from the engine is used to charge up the batteries. Likewise, when the car is slowing down, the regenerative brakes convert the lost energy into charge in the battery.

The beauty of the system is that you won’t notice this happening, and there’s no need to ever plug the car in or for any home charging. However, the con to that pro is that you won’t get the same level of fuel economy that you would in a plug-in hybrid. Once the batteries are depleted or you need some extra performance, that petrol engine kicks into life – which you’re most likely to spot at higher speeds or on longer journeys.

In other words, you’ll get the best economy out of an RC 300h is you spend much of your time on short journeys or around town. If your motoring diet consists more of long-distance motorway runs, a rival with a diesel engine (which Lexus doesn’t offer) may give you better economy in the (every pun intended) long run.