BMW 320i and 320d

AutoTrader NZ
Published 3 October 2021

The Perception of Weight: Diesel vs. Petrol

The mind can play strange tricks. Jump from a drive in a BMW 320i into a 320d and it actually feels as if the diesel is a larger car than the petrol model. That’s despite the fact that both cars are identically specified SE versions running on the same 205/55 Continental tyres and 16-inch alloy wheels. The diesel version is 95kg heavier and the modest increase in mass over the front wheels could have a marginal effect on the balance of the vehicle.

Noise and Vibration: Affecting the Perception

Yet the real reasons for the perception that the diesel is a heavier car are noise and vibration. It’s not so much a matter of the 320d lacking in refinement – more an acknowledgement of the superb silence and mechanical excellence of the 320i Valvetronic petrol motor.

The Appeal of Smaller Engines: 320i and 320d

My plan was to back-to-back two of the smallest-engined 3-Series BMWs sold in New Zealand. Most buyers opt for the larger capacity six-cylinder versions, but they are much more expensive and consume more fuel. Can you truly enjoy the experience of the new E90 3-Series with a smaller four-cylinder motor and without the sticker price breaking the bank?

Market Sales and Value: 320i vs. 320d

Both the 320i and 320d prove you certainly can. Though the E90 was on sale for only part of last year, the sales figures confirm the 330i is the biggest selling variant, followed well behind by the 320i and 320d. New Zealand’s luxury car market is still nervous about diesels when it has no right to be. Yet ironically, the 320d is the best value 3-Series model in our market. Both the 320i and 320d are available in base and SE forms, with no price penalty for the diesel.

Price Comparison and Justification

Globally, most markets price their diesels above the petrol because of higher diesel engine manufacturing costs, increased efficiency, performance and longevity – and because the markets can stand a higher price. In Britain you need to stump up the equivalent of nearly $5000 more to own the 320d over the 320i. Wonder how you could justify spending that much more before pondering on the retained value of the car two or three years down the line? The extra expense is more than recouped as a secondhand car, and the vehicle has cost less to run. Different rules apply in our country.

Pricing Dispensation and Sales Preference

As Mark McCutcheon, BMW NZ’s sales chief, says, we have dispensation from the pricing penalty because car franchises still need to win consumer acceptance for diesel performance/luxury models. As a result, the 320d is something of a snip at $66,900 or $74,900 in SE trim. Substitute the six-speed manual gearbox for the six-speed automatic, and the respective prices are $70,900 and $78,900. If you’re objective, the diesel is the logical choice every time. Yet buying up-market cars is not about logic or reason, which explains why 320i sales in New Zealand last year were more than 40 percent higher than 320d.

Performance and Fuel Efficiency: 320d Advantages

I drove the 320d first and was so taken by the strong performance that I figured BMW had given me a six-cylinder 330d by mistake. They hadn’t. Most New Zealanders opt for two-pedal motoring, so it was not surprising both test cars were automatics. The second-generation common rail diesel combines brilliantly with the silky smooth auto, but it’s the immense torque that is most impressive.

The four-cylinder diesel has twin balancer shafts, variable-nozzle turbocharger and direct injection. It produces a hefty 340Nm of torque at just 2000 revs, outgunning all other 3-Series engines with, of course, the exception of the 3.0-litre diesel. With 70 percent more torque than the 200Nm 320i, the 1995cc diesel is a clear winner in on-road performance, especially in mid-range urge. The 0 to 100km/h sprint time of 8.6 seconds is 1.1 seconds quicker than the petrol BMW’s.

At 120kW, the 320d is nine percent more powerful than the 110kW 320i, and its 225km/h top speed is 10km/h higher. The diesel pulls from less than 1000rpm and achieves peak power at 4000rpm – 2200 revs less than the 320i.

When it comes to fuel economy, the differences are even more spectacular. We ran two fuel checks over easy touring conditions, and the diesel was 50 percent more economical. The 320d posted five litres/100km (56.5mpg) where the 320i returned 7.8 litres/100km (36.2 mpg). So, is this a total walkover for the diesel? Well, no, not exactly.

The 320i petrol clearly wins the refinement race. It’s a sweet, easy-revving motor with enough performance for most owners and, unless pressed, is remarkably quiet. Unlike the diesel, the 320i power unit is hardly audible at idle and on the move it’s one silent car.

The E90 3-Series is a superb driver’s car with an immensely rigid chassis and near-perfect weight distribution. At slow speeds, the steering may be a touch heavy for some drivers, but the car is involving and satisfying. MacPherson strut front suspension and a five-link rear end combine with ideal wheel location in a carefully measured way to produce a car with near-perfect manners.

Run-flat tyres mean no spare wheel and a harsh slow speed ride because of the tyres’ heavily reinforced sidewalls. On indifferent surfaces, the busy, firm ride takes the edge off occupant comfort and is disappointing.

A nice aspect of the smaller-engined 3-Series models is their simplicity. Some may brand the interior as bland, but it’s more likely tasteful and functional. The dashboard is no-nonsense clean, with sharp instruments and easy-to-learn controls. I miss a water temperature gauge even though BMW engineers say one is no longer necessary.

Few self-respecting BMW owners will want a 3-Series with steel wheels and covers, but the entry-level 320i and 320d are otherwise reasonably well equipped for our market. They include electronic controls for cornering braking, dynamic braking, dynamic stability, and traction.

Park distance control is standard on the rear, which is just as well given the poor visibility through the back window. Upgrade to SE and PDC extends to the front. But I can’t imagine anyone buying the standard model without air conditioning because it would be sale-proof. Air conditioning adds $1910 to the price. The SE has it as standard and adds cruise control, a sports leather steering wheel, leather upholstery, and interior finishers in brushed aluminium.

Apart from the gimmicky push-button for starting and stopping the engine and a rear seat more suitable for two adults than three, the 3-Series sedan is hard to fault.

And the outcome of this test vindicated the real worth of the 320d and 320i that are hardly poor relations when mixing with their larger-engined brothers.