If there are two words that don’t normally go hand in hand, it’s ‘power’ and ‘economy’. Some would say when it comes to motor vehicles you can’t have both, but in an Isuzu D-MAX, they work together harmoniously. As our recent Max Run Challenge proved, a D-MAX can go far on a single tank of diesel if you drive and maintain it correctly. It all begins with Isuzu’s refined 3.0-litre 4JJ1 engine, which ensures torque is available from idle. At just 1000rpm, 73 per cent of total torque is on tap, with maximum torque achieved and maintained at 1800rpm through to 2800rpm. This means you’re getting plenty of power without the engine working overtime and consuming unnecessary fuel. The manual and automatic transmission ratios have been specifically matched to maintain legal cruise speeds at around 2000rpm, giving maximum torque where it’s needed most. This is the D-MAX’s biggest secret exposed—and why the vehicle can achieve the best fuel economy figure in its class for automatic transmission models, an impressive 8.1L/100km. Here are our top 10 tips to achieve maximum fuel efficiency in your D-MAX.
One: SPEED CAN HURT YOUR WALLET IN TWO WAYS
Drive too fast and you’ll get caught. But it’s not just the risk of a speeding fine that will play havoc with your bank balance.
Reducing your speed will reduce the amount of fuel consumed by the engine—the faster your vehicle goes, the more effort is required to get it there and maintain it. At 110km/h, your engine can consume as much as 25 per cent more fuel than if you were travelling at 90km/h.
TWO: DRIVE SMOOTHLY
Aggressively accelerating or braking not only makes you look a bit silly, it wastes a substantial amount of fuel. When pulling away from the lights, try to accelerate gently. Avoid harsh braking and hard acceleration—be soft on the throttle and smooth on the brakes. Less throttle means less brake applications. Where possible, make use of the D-MAX fuel shut off on deceleration and coast to a stop.
THREE: KEEP YOUR VEHICLE WELL MAINTAINED
Be sure to get the specified maintenance procedures carried out on time, using the correct fluids, filters and lubricants. Clean oil and filters are essential to get the best performance and maximum efficiency from your engine.
It’s simple—the heavier your vehicle is, the more engine power it requires to move it. So don’t use your vehicle for additional storage. Make it as light as possible and only carry what you need.
Make sure your tyres are checked for wear and damage on a regular basis—ideally, you should do this weekly. Ensure your tyres are inflated to the correct pressures. Refer to your tyre placard fitted inside the driver’s door panel, or your owner’s manual. Different conditions, loads and speeds require different tyre pressures, and maintaining the correct tyre pressure will reduce the rolling resistance between your D-MAX and the road, further reducing the effort required to drive your vehicle, and hence reducing fuel consumption. Also, ensure your wheels are correctly aligned—particularly if you drive off-road. When going bush, knocks and big bumps can upset the balance of your car when you get back on the bitumen, creating more work for your engine.
SIX: REDUCE AERODYNAMIC DRAG
Roof racks, roof-mounted cargo trays, ladder racks and even larger exterior mirrors all change the shape of your roof line and vehicle profile, creating additional drag, which in turn decreases fuel economy. Make sure you remove any unnecessary items from your roof racks or tub, and keep the vehicle clean—polished is best—to aid the slipstream effect. If towing a large van, a roofmounted scoop will help deflect wind over the van.
SEVEN: USE YOUR AIR CONDITIONER WISELY
Using air conditioning places more load on your engine. A slight increase in effort is required as the air conditioning pump takes a small amount of engine power to run. While driving at higher speeds—say, 75km/h or above—leaving the window down creates more drag and hence engine effort than operating the air conditioning system, so it’s best to wind the window up at speed. If the ambient temperature isn’t extreme, keep the air conditioner off and have the cabin fan on to increase interior airflow with the windows up, with the fresh air vent open and not on recirculation.
EIGHT: ALWAYS DRIVE IN THE CORRECT GEAR
When driving a D-MAX equipped with an automatic transmission, the best suggestion is to leave the transmission shift up to the expert— the transmission computer—especially when towing. When driving a D-MAX fitted with a manual transmission, be aware that driving in a gear lower than you need uses fuel by increasing the engine RPM. Make sure you change up into a higher gear as soon as it’s possible and safe to do so. This will maintain a steady cruise speed using the engine torque. You’ll feel the torque ‘pull’ as the vehicle gains speed.
NINE: PLAN YOUR JOURNEY
Are you going out to run all your weekly errands, or are you just dropping a letter off at the post office before heading back home? You will essentially cut distance travelled and fuel usage in half by making all your stops at once, instead of taking lots of short roundtrips. Cold engine fuel use and emissions are higher until the optimum operating temperature is reached. As a rule of thumb, this can mean up to 10 kilometres of normal driving before it reaches that point.
TEN: MINIMISE FUEL CONSUMPTION
Your D-MAX’s diesel engine has many features to aid economical fuel consumption. It has an engine warm-up cycle to get things to running temperature as fast as possible, reducing unnecessary engine wear as well as preventing excessive fuel use. The D-MAX engine also shuts off fuel delivery on deceleration, meaning when the throttle is closed and the engine is in an overrun situation, no fuel is consumed—for example, when coasting down a hill.