BOXER engines are a Subaru trademark, so it was no surprise that when the company built its first diesel, it had pistons firing out to the sides just like its petrol-powered range. So far, Forester diesel accounts for about 10 per cent of Forester sales – to be expected as diesel-powered compact SUV take up is small. Buyers know that the diesel efficiency benefit is far less than with large SUVs and manufacturers – including Subaru – tend to add a premium for the diesel engine option. The question is, does Subaru’s first diesel engine match the sophistication of its better competitors?