Which Subaru Forester is better - diesel or petrol?

The Subaru Forester is one of the safest SUVs on our roads and has enjoyed a five-star safety rating for almost as long as we can remember. If you’ve been dreaming of a diesel Forester, you’ll have to settle for an older model which is as hard to find as hen’s teeth…

Ané Albertse

11 Aug 2022 · 08:32Buying a Car

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Previous-generation Foresters in South Africa all came equipped with Subaru’s 2.0-litre horizontally-opposed (also known as a “flat-four”) B4 boxer direct-injection petrol engine, which looks and functions differently from the traditional layout of four-cylinder engines we find in most cars today. The 2.0-litre boxer engine first made its appearance in the SA Subaru lineup as an all-new model in 2013.

What’s a boxer engine?

The Subaru Boxer Engine is named after the horizontal movement of the pistons - “much like boxers throwing punches”, says Subaru:

“We firmly believe that the Horizontally-Opposed Engine is the optimum design for driving enjoyment. The pistons face away from each other in a 180º symmetrical layout around the crankshaft and work to balance out each other's vibrations, delivering a smooth, shudder-free feel. This is because the engine can rotate freely at any given speed, delivering a heart-gripping response to the driver.

“The length and height of this engine layout can be kept shorter than a traditional in-line engine, and it is also lighter. The engine can be mounted lower in the vehicle than other engines, and the weight balance on the left and right can be made almost exactly the same. In this design, the centre of gravity of the entire car is lowered. Similarly, a symmetrically balanced engine improves the balance of the entire car. Both of these aspects combine to deliver a safer, more stable, and more enjoyable experience on the road.”

What this means for the driver, is a more controlled ride, less noise inside the cabin while you drive, better fuel economy, and a better chance of walking away unscathed in case of an accident.

The 2.5 had a bit more oomph

Up until February 2015, the Subaru Forester’s engine of choice was another naturally-aspirated 2.5-litre boxer engine which fell away in 2016. The most recent 2.5-litre Forester had 126kW and 235Nm on tap and fuel economy was a reasonable 9,5 -11 litres per 100km. Owners of this particular Subaru also reported that fuel economy kept on getting better, even as low as 8.7 in the city and below 8 on the highway.

There once was a diesel Forester too

The 2.0-litre turbo-diesel Boxer engine with 110kW and 350Nm had a brief stint in South Africa from only 2011 to 2012, so these models are scarce. We checked on the AutoTrader website, and only managed to find one! This engine preferred 50ppm diesel, and real-world fuel consumption was rated at 7.7 km per 100 km, which is rather good when you have 350Nm of torque at your disposal. The open road should see that figure fall as low as 6.7 litres per 100 km.

Those who had the pleasure of driving this particular Forester were very impressed with the engine, but not many models were sold here and it was discontinued as a result.

So, which engine is the best?

If you’re buying used, maybe the diesel isn’t the best option; if you can find one, that is! Our local diesel is of poor quality and if you’re looking at a 2011 model, it’s getting a little long in the tooth in terms of upkeep. It is also said that the injectors were expensive to replace. If you are married to a mechanic or the family business is an automotive workshop, this shouldn’t be a problem, though.

That really leaves the pre-loved 2.5 and new or used 2.0-litre engines to choose from. From a pre-loved perspective, would pick the bigger engine because you won’t need to drive it as hard, which is better for a car’s health in the long run. The 2.0-litre engine mated to the CVT gearbox does not make for the swiftest progress, especially since the Forester is neither light nor small. It has 115kW and 195Nm of torque, and a 0-100 km/h sprint time of 10.3 km.

Buying new? Subaru now has a 2.5-litre model which joined the lineup in 2022.

Search for new and used Subaru Foresters on AutoTrader

See the latest Subaru Forester reviews

Watch Chad Luckhoff's video review of the Subaru Forester 2.5i-Sport ES here.

You can read Sean Nurse's review of the Subaru Forester 2.5i-Sport ES here.

Written by Ané Albertse

Ané was bitten by the motoring bug at a very young age. Her mom recalls her sitting in her stroller as a 3-year old, naming every car that came past. She was creating content for various publications within Media24 when AutoTrader nabbed her for good, and is one of the longest-standing members of the AutoTrader team. She prefers dirt roads to tar and SUVs/bakkies to sports cars, but her greatest passion is helping people find the perfect car for their budget, lifestyle, and personality.Read more