Parkers overall rating: 2.5 out of 5 2.5

Miles per pound (mpp) Miles per pound (mpp)

Hybrid petrol engines 3.9 - 4.7 mpp
Low figures relate to the least economical version; high to the most economical. Based on WLTP combined fuel economy for versions of this car made since September 2017 only, and typical current fuel or electricity costs.

Fuel economy

Hybrid petrol engines 26.2 - 31.4 mpg

Infiniti Q50 running costs are kept well in check via a pair of efficient engines and drivetrains. The diesel engine with manual gearbox manages to emit only 114g/km of CO2, so annual road tax is in one of the lowest bands available. That figure does rise with the seven-speed automatic ‘box specified but only by 10g/km so road tax is still reasonable.

Overall economy is great too, with a claimed combined figure of 64.2mpg, which means a theoretical 1,045-mile range. Choose the automatic model and that range drops to around 960 miles thanks to its 58.9mpg combined economy, though in our time with the car it appears a figure between 44-46mpg is more likely.

Even the high-performance hybrid toes the line when it comes to running costs; its 144g/km CO2 figure means annual road tax is reasonable and theoretically it can average 45.6mpg or 41.5mpg when fitted with the four-wheel drive system.

If your primary concern is how low Infiniti Q50 emissions are – if you’re a company car user for example – then the 2.2-litre diesel on standard wheels and with the manual gearbox is your only choice. Opt for this model and the CO2 output is a very reasonable 114g/km.

Choose the Sport, with its 19-inch alloys and this rises to 118g/km while adding the seven speed automatic increases the figures to 124 and 128g/km respectively.

It’s actually the Hybrid model that is the most polluting, despite the environmental connotations usually associated with such technology. The good news is even with its 359bhp power output the four wheel drive model manages to only pump out 159g/km.

If there’s one thing the company can do it’s look after its customers, so in the unlikely event that Infiniti Q50 reliability isn’t as stellar as we’d expect owners won’t feel much pain.

That said, the diesel engine – which is likely to be the most popular – is actually a development of the popular Mercedes Benz 2.1-litre unit. Without too many changes, we’d expect it to perform faultlessly in the Infiniti. The hybrid unit is related to the engine found in the M35h, and we’ve not heard of any major issues with that car either.

It's loaded with new technology though, and there is a fear that the more kit the more there is to go wrong down the line – though with Infiniti’s track record that is probably unfounded.

Ongoing running costs

Road tax (12 months) £30 - £490
See tax rates for all versions
Insurance group 30 - 43
How much is it to insure?