In-depth reviews

BMW 3 Series review - MPG, CO2 and running costs

Excellent economy and decent CO2 emissions make the BMW 3 Series a good choice for business and private users

The latest 3 Series offers decent economy across the board; driven sensibly, even the sporty M340i can get very close to 35mpg on average. CO2 emissions are relatively low – good news for private buyers and company car users alike. All quoted figures here are for the saloon – Touring estate buyers should factor in a slight dip in economy and an increase in emissions on account of the extra weight.

The 320d SE, with mild-hybrid tech, is the most economical choice, with a claimed maximum of 61.4mpg and CO2 emissions from 119g/km. Adding xDrive to the spec brings a further emissions increase to 130g/km – along with fuel economy of 57.6mpg. It’s worth sticking with the rear-drive option unless you plan to make regular use of the four-wheel drive system’s improved traction in inclement conditions.

The powerful 330d does not suffer too much in terms of economy despite its six cylinders and 261bhp. Rear drive models return a maximum 56.5mpg and emit 132g/km of CO2, while xDrive models take a slight dip in fuel economy and release eight more grams of CO2 per kilometre. 

Those that are seeking even more grunt won't be left too short-changed, the M340d xDrive manages to combine a 335bhp output with an outstanding 46.3mpg on the combined cycle.

The most efficient of the petrol engines is the 318i SE with a claimed 44.1mpg and 144g/km of CO2. Almost the entire petrol engine range sits around this economy range; even the 330i returns up to 41.5mpg on average, with CO2 emissions from 148g/km.

The M340i is the least efficient model in the range, but still achieves a claimed best of 36.7mpg on the combined cycle, with CO2 emissions of 176g/km. 

The 330e plug-in is capable of travelling over short distances without using any fuel – its battery will provide up to 37 miles of electric range when fully charged. It’s this ability that helps the 330e achieve its impressive 201.8-217.3 maximum claimed economy and 30g/km CO2 emissions – though you’ll be hard pressed to match these figures in real life on longer journeys. It’s definitely the best choice for lower-mileage, shorter-distance drivers, however – keep your battery charged up and you could conceivably not use any fuel at all on shorter journeys.

Insurance

Insurance groups for the 3 Series saloon and Touring models are competitive and range from 24 for the 318i SE Pro petrol version to group 42 for the M430d xDrive. The mid-range 320i and 320d saloon models, in popular M Sport trim, sit in group 29 and 30 respectively.

Depreciation

Thanks to the lure of the premium badge the BMW 3 Series has never suffered from terrible rates of depreciation, but as with the C-Class and the Audi A4 the sheer number of these premium models being sold each year has ultimately had a slight softening effect on their residual values.

The average retained value for the range after three years and 36,000 miles is around 45%, with the 318i petrol and 330e plug-in hybrid models holding on to nearer 50%. 

Which Is Best

Cheapest

  • Name
    318i SE Pro 4dr Step Auto
  • Gearbox type
    Semi-auto
  • Price
    £32,125

Most Economical

  • Name
    330e SE Pro 4dr Step Auto
  • Gearbox type
    Semi-auto
  • Price
    £40,425

Fastest

  • Name
    M340i xDrive MHT 4dr Step Auto
  • Gearbox type
    Semi-auto
  • Price
    £50,095

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