After months of research to choose your new four-wheel-drive, there often remains one uncertainty: diesel or petrol?


Historically, diesels were respected for robust longevity, greater fuel efficiency and ability to work long and hard by pulling heavy loads all day. Diesels seemed the perfect partnership for early 4WDs when considering remote outback travel or for towing the family yacht or caravan.

The fuel is less volatile for storage and more readily available in remote locations.

But there was a trade-off: diesels were noisy, lacked refinement, and had asthmatic performance at best.

Three cheers for technology, that’s all a distant memory. With the aid of modern design, forced induction, electronic management and lightweight materials, the diesel’s hidden potential was unlocked. The humble rattly oiler has come of age in a rebirth of astonishing capability and refinement; look to BMW’s Alpina D4 Biturbo for the ultimate proof.

Quieter, with impressive torque delivery offering brisk on-road response and determined off-road capability.

So is the petrol option redundant?

With manufacturers pushing to meet ever-increasing restrictions on emissions, there’s a trend to develop smaller-capacity engines. Innovative designs combining multiple turbos, or a turbo and supercharger, produce impressive levels of lowdown torque with better driving dynamics often matching or exceeding the output of larger-capacity predecessors with better fuel efficiency and lower CO{-2} emissions.

Land Rover’s supercharged 3.0-litre petrol V6 is a good example as it relinquishes nothing to the superseded 5.0-litre V8.

Petrol engines are still generally more refined with a smooth delivery of power, higher in the rpm range. Ideal for short stop-start daily commuting, they offer crisp throttle response and acceleration.

Don’t think for a minute the petrol is the underdog — it can hold its own off-road and while it may require a little more rpm in some conditions, it’s a force to be reckoned with in soft sand as proved by Nissan’s latest V8 Patrol wagon, which devoured every sand dune we threw at it.

 

Nissan’s new high-tech petrol V8 devours sand dunes. Picture: Ray Cully


Petrols are more forgiving if you ingest a little water during a river crossing. They can have a cost advantage at purchase over the diesel variant and the money you save will go a long way to topping up the tank.

Repairs to a diesel engine or its fuel system cost considerably more than equivalent maintenance on a petrol engine, due to the nature of the diesel’s construction.

So when choosing between petrol or diesel, consider what you will do with your 4WD.

As the family daily driver with an 80/20 split of suburban black- top and the occasional family getaway, and maybe the odd dunking of the dinghy at the boat ramp; petrol will provide a smooth responsive drive and easily accommodate your needs.

But if you’re planning to cover long distances and pull a heavy load to remote locations, or to work the vehicle for long periods in arduous conditions, then diesel is probably the better option with its robust construction and fuel-efficient capabilities.

The humble rattly oiler has come of age in a rebirth of refinement.

 

© The West Australian