|The story: With the ongoing debate about the future of diesel emissions, is it worth looking at the petrol alternative to BMW’s all-conquering 520d?|
|Key rival:||Audi A6|
As a fuel, diesel took something of a battering during 2017, and the tax changes announced in the chancellor’s Budget guarantee that will continue into 2018 and beyond, and that’s despite the likes of BMW claiming there is minimal difference in terms of NOx emissions and therefore local air pollution between their modern petrol and diesel engines.
Nevertheless, BMW offers a petrol-powered 520i alternative to the very popular diesel 520d that is still the popular and traditionally overwhelmingly sensible choice for company car drivers.
The petrol is only 6hp down on the diesel, and therefore has almost the same performance: its 0-62mph time of 8.2 seconds is only 0.4 seconds behind the diesel’s. However, there is a huge 17g/km difference on emissions that equates to a 14.9mpg gap in favour of the diesel, which is the decisive number. The extra £1,500 or so spent on fuel over three years and 60,000 miles negates a residual value difference that means the two will be worth the same after 36 months, despite the diesel starting £1,000 more expensive.
From a company car driver’s benefit-in-kind perspective, the extra band that the chancellor added to diesel BIK tips the balance in favour of petrol, with a 40% tax payer taking a car in January for three years paying the Treasury just under £250 less on the BMW 520i than the BMW 520d. But the diesel’s extra efficiency will hit the private miles of a petrol driver, so much of the £250 will just go to the oil companies instead of the Government, with a real-world difference likely to be more than 10mpg in our experience. Take your pick.
Going from a BMW 520d to a BMW 520i, drivers will miss the diesel surge that characterises BMW’s excellent oil burner, but the petrol is quieter and more refined, and is happy to perform when you work it.
As with all mainstream BMW 5-Series models, the 520i comes in SE or M-Sport trims and in saloon or Touring forms, although unlike the BMW 520d, you can’t have it with xDrive four-wheel drive.