LIGHTNING performance from big V6-powered executive models doesn't generally go hand in hand with small family car economy.

That's unless you have a hybrid system combining two separate power sources - and no one does that bit better than Japanese giant Toyota.

Take the fourth generation GS 450h luxury sports saloon from the company's prestige arm Lexus.

This is a car that can storm to 62mph in a mere 5.9 seconds and on to a potential top speed of 155mph, yet can return more than 40 miles per gallon in the least economical urban conditions. The combined, or average, figure rises to 45.6.

Yet beneath the car's bonnet is a 3.5-litre V6 petrol engine. Thankfully it's mated to a 147kw electric motor, with the result of a collective 341bhp of punch - delivered with silky smooth precision.

The latest GS range comes with a choice of two powertrains, the full hybrid GS 450h featuring the second generation Lexus Hybrid Drive, and the GS 250 powered by a 2.5-litre V6 petrol engine new to the line-up.

The 450h is especially attractive to executive company car drivers, not only because of the terrific fuel consumption, but also because of the 141g/km emissions and subsequent 19 per cent benefit-in-kind tax.

On the road the GS performs smoothly and efficiently, the electric motor cutting silently in and out while the automatic six-speed gearboxbox is very sweet and you can use the paddle change as an alternative.

Both GS versions come in Luxury and F Sport grade, the latter looking more aggressive with 19-inch rims, a boot-lip spoiler and sports-styled bumpers to go with the new spindle-shaped upper and lower grilles.

There's a real premium feel inside the leather-clad cabin, the centrepiece being a 12-inch multi-display screen for the built-in sat-nav, radio and phone displays.

In addition to the comprehensive Luxury spec, F Sport also brings bi-xenon headlights with an auto high beam function, as well as adaptive front lighting, which adjusts the beam direction as the car approaches bends.

Sports pedals and perforated leather-trimmed sports steering wheel and gear knob plus electrically adjustable front seats are included along with ample space for two in the back, though a centre rear passenger has to make do with an uncomfortable perch.

The front sports seats gain further adjustment functions - 16-way for the driver, plus four-way lumbar support.

The F Sport benefits from Adaptive Variable Suspension and selectable drive modes plus, on the 450h model, the Lexus Dynamic Handling System which brings together a comprehensive array of steering and handling features.