Lexus RX review - MPG, CO2 and running costs

The Lexus RX was an early adopter of hybrid technology, and every version of the flagship SUV is electrified. The range kicks off with the RX 350h, which uses Lexus and Toyota’s tried and tested ‘self-charging’ hybrid technology, with a 2.5-litre four-cylinder petrol engine under the bonnet. This version will return up to 44.8mpg, according to Lexus, and emits 143-149g/km of CO2 – both significant improvements over the previous-generation RX 450h.

Then there’s the Lexus RX 500h, a “performance hybrid”, producing 366bhp from its turbocharged 2.4-litre and a 107bhp electric motor mounted on the rear axle. Unsurprisingly, this is the thirstiest RX available, capable of returning up to 35.3mpg and CO2 emissions of 182-189g/km. Although our test drive was more boisterous than the average owner will engage in, we think most RX 500h drivers would struggle to get an mpg figure into the thirties.

But if you’re really looking to cut down on your running costs, then it’s the plug-in hybrid RX 450h+ you’ll want. This version also features a 2.5-litre four-cylinder petrol engine coupled with an electric motor fed by a 18.1kWh battery located under the floor. CO2 emissions for the RX 450h+ stand at 25-26g/km, while Lexus claims the first-ever plug-in RX can return up to 256.7mpg, although we doubt many owners still see close to that figure day to day – as is the case with a lot of plug-in hybrids. 

The 450h+ also has an electric driving range of around 40 miles, and we expect most people should get near to this figure with careful driving. But plug-in hybrid versions of the BMW X5, Mercedes GLE and Range Rover Sport will go even further without using a drop of petrol.

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There is a second battery in the 450h+ that allows it to run as a self-charging hybrid, which is a nice safety net to have if you forget or can’t charge the car as regularly as you’d like. However, you still need to charge the car regularly if you want to maximise the electric-only range or get the best fuel economy possible. Fully recharging the 18.1kWh battery via a standard 7.4kW home wallbox takes just under three hours. 

Benefit-in-Kind (BiK) rates also favour the plug-in hybrid 450h+ because it attracts an 8 per cent BiK rating, compared with the 33 to 37 per cent you’ll pay on one of the self-charging models. That means a top-rate taxpayer will face annual charges of at least £2,077 to run an RX 450h+, compared with £7,877 for the cheaper, but less efficient base RX 350h or nearly £11,000 for the range-topping RX 500h.

Insurance groups

As you might expect for a large luxury SUV, insurance ratings for the Lexus RX range are pretty high. The entry-level RX 350h sits in insurance group 42 or 43, depending on which trim level you go for. It’s the same story with the plug-in hybrid RX 450h+, which lands in group 44 or 45, while the RX 500h (available exclusively in F Sport specification) falls in insurance group 46.

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Depreciation

After three years and 30,000 miles, the latest Lexus RX should retain around 60 to 62 per cent of its value, so you can expect it to hold its value better than a Volvo XC90 and some variants of the BMW X5.

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