First up is the efficiency. The Yaris majors in this area, thanks to the flexibility of the hybrid powertrain and its ability to sip fuel. I thought the LBX would impress here too, considering its ties to the Yaris; Toyota promises 68.9mpg on the combined cycle.
Lexus claims a little less for the LBX, at 61.4mpg – understandable given the extra kerb weight (1,280kg to the Yaris’s 1,090kg) and additional power (the LBX has the same 1.5-litre three-cylinder petrol hybrid, but with 134bhp rather than the supermini’s 114bhp).
Despite our best efforts, however, we’ve struggled to match this, returning 48.1mpg so far. We’ve tested efficiency in various ways, singling out motorway and urban driving without success. There is, of course, the EV-only mode – although the 1.01kWh battery is small and only works at up to 30mph.
You also have to be ultra-sensitive with the throttle to not awaken the petrol engine. Plus it’s rare that the battery and electric motor combination seems to be able to function alone, and regular ‘EV drive mode unavailable’ warnings are appearing on the dash.
Having looked at the receipt for the battery ‘state of health’ provided with the car’s registration, I found out it was rated ‘good’ with a measured voltage of 263 – between the nominal output of 201 and the system voltage of 280. If there’s no uptick in efficiency soon, I may request the services of Lexus to see whether there’s some other issue at play here.
