A sub 160g/km CO2 figure brings the luxury sports saloon under a key tax threshold for the first time – benefiting company balance sheets and saving drivers money. There’s even a small extra bonus on fuel consumption – without any loss of the car’s pacesetting performance.

At 159g/km, the latest Infiniti M35h qualifies for the higher rate of Write Down Allowance (WDA), allowing companies to claim 20% of the car’s cost as capital expenditure per year. Cars with CO2 of more than 160g/km can claim only 10% WDA per year.

The lower emissions figure also drops the M35h one tax band for drivers, from 23 to 22% for 2012/13, saving a 40% taxpayer around £180 a year. Already the Infiniti M35h’s tax liability for company drivers is substantially lower than petrol saloons with similar performance.

The latest Infiniti M35h is just what newly-appointed UK Fleet Sales Manager Simon Lewis wanted. He said: “The Infiniti M35h is already popular with companies seeking a luxury saloon with no compromise on performance or fuel consumption. Now with its no-compromise approach to running costs, it offers fleet buyers a car that is both hugely enticing and entirely sensible – a combination we think they will approve of.”

Rather than resort to specification tweaks such as fitting low rolling resistance tyres to lower CO2, Infiniti engineers found the emissions-reducing answer in technology. Key enhancements to electric motor accuracy and battery charging allow the Infiniti M35h to rely more on silent electric power when starting off from cold, bringing benefits that go beyond just cutting running costs.

As well as lowering CO2 the changes bring improvements across the EU fuel consumption spectrum; the combined figure for the 359bhp (364PS) petrol/electric model improves by 0.5mpg to 40.9mpg, while on the highway cycle the Infiniti M35h is now credited with more than 50mpg.

Low fuel consumption in everyday driving was independently confirmed in the 2011 MPG Marathon when the M35h returned an overall 43.4mpg over a varied 370-mile route, with almost half the distance covered on electric power alone. Recording a 6% improvement on the official combined figure, the M35h easily won its class – while the other hybrids taking part failed to match their official figures.

Faster than Porsche and BMW hybrid rivals with 0-62mph in just 5.5 seconds, the M35h’s position as performance champion was sealed in 2011 when Guinness World Records officially declared it the fastest accelerating hybrid in the world after independent testing at the UK’s Santa Pod Raceway.

At £46,840 the single model for the UK boasts everything as standard (apart from metallic paint choice) at a margin over an equivalent Infiniti M30d of just £1180 – substantially less than the hybrid premium charged by some rivals.