Ask The Guide

My initial thought is that 11 or 12 litres per 100km for an overall average is about what I would have expected. These are not small cars, they’re not light and they have fairly ordinary aerodynamics.

What you need to keep in mind is that the official fuel consumption figure is a number achieved on a very specific test cycle that in no way approximates a real-world experience. Car makers go to great lengths to nail a good number on these tests (for marketing purposes) often at the expense of real-world fuel economy. Yes, it does seem crazy, doesn’t it?

You also mentioned you use your car mostly for high-speed driving. What’s your definition of high speed? Thanks to the aerodynamics of vehicles like the MU-X an extra 10km/h at freeway speeds can have a huge effect on economy. Even removing a roof-rack when you’re not using it can save a litre per 100km.

A car with a little extra ground clearance is great for camping as it often allows you to get a little farther away from the masses in their caravans who tend to huddle around the shower block at bush campsites.

The Subaru Outback is a good, solid choice and if you can find an independent workshop to service it, you’ll avoid the cost of dealership prices. And you’re right, the all-wheel-drive would be great for gravel roads. Another vehicle to look at would be a late-model Ford territory diesel which is big and clever inside and has the option of all-wheel-drive. The diesel engine is a plus on the bush where that fuel is more readily available (in really remote areas) and gives you more range for big holidays in the mulga.

Don’t rule out things like the Mitsubishi Pajero, either, which won’t be as around-town friendly, but is a proven quantity and is absolutely tremendous off-road. The same goes for a Toyota Prado or Nissan Pathfinder prior to the current model (which is a bit less hard-core adventure).

You raise an interesting point, Phil. A lot of people don’t understand that as you approach the towing limit of some vehicles, you also get very close to the legal Gross Combination Mass (GCM) which means you have virtually no payload left.

As for the torque of the 6.2-litre V8 engine, while it may not have quite the low-speed punch of a modern turbo-diesel, with 624Nm of torque, the engine is no lightweight, either. Frankly, it should do the job about as well as anything else out there. I’m not aware of a factory retune for the Silverado, but the engine is shared with plenty of GM and Holden product and there’s a whole industry in hotting those up. Surely somebody can offer you the tune-up you’re looking for. By the way, success on a boat ramp tends to be more about grip than torque.

Your electrician has done the right things so far, Ken, starting with making sure that the battery is charged and being charged by the alternator and that the car is earthed (grounded) properly. Those are traditionally major causes of this type of problem, but unfortunately there are many more possibilities in a modern car with its electronics. My first thought is that the functions you’re having trouble with are all controlled by the car’s body computer. So I think that’s where your electrician should start looking next. These computers can develop software and hardware faults that allow for these random and intermittent problems. So maybe borrowing a body computer from the same make and model and seeing if that fixes your problems (and at least ruling out the computer) is a cost-effective way forward.

I’d also be having a chat to the workshop that replaced the steering rack to see if there’s any way that a connection or sensor related to the on-board computer could have been bumped or damaged during the rack-replacement process. It would certainly be a coincidence (and it’s possible that this is exactly what this is) if these problems started straight after the repairs, no?

Surprisingly, your car would probably run on E85, but it wouldn’t run properly. E85 is 85 per cent ethanol (and 15 per cent petrol) which has a lower energy content than straight petrol. As a result, a car running on E85 will need to use up to 30 per cent more fuel by volume to work properly. As your car is not tuned for this, it would probably run but would be down on power and may not idle or accelerate smoothly.

The bigger issue is that the high ethanol content fuel can be corrosive to fuel system parts (pumps and lines) not designed for it. While many Subaru models are, in fact, compatible with and suitable for E10 fuel (10 per cent ethanol and 90 per cent petrol) E10 has an octane rating of 94 while your car requires a minimum of 95-octane fuel. So even E10 would be a no-no.

With all that in mind, I think the best advice would be to drain the tank of the E85 as soon as possible. Refill it with 98-octane petrol and go for a drive to purge any residual E85 form the lines. Your workshop may even suggest a new fuel filter. If they don’t, ask about it yourself. The good news is that it’s very unlikely you’ve done any damage beyond the dent you’ve just put in your wallet.

Anything can be made to work if you throw enough money at it, but the short answer, Bassel, is no. For the 2014 model year, Hyundai upgraded the petrol engines in the iX35, and the two-litre unit in your car received a direct-injection fuel system. While the basic engine architecture might be the same and the engine would probably physically bolt in, it’s almost certain that the computer in your car would be incapable of controlling the direct fuel-injection function. Your car is also probably missing components such as wiring, a high-pressure fuel pump and sensors required to make the newer engine operate.

You could also run afoul of the authorities because the earlier engine you want to use had a (slightly) higher tailpipe emissions rating. Our regulators take a fairly dim view of a vehicle being modified and going backwards on emissions.

That’s definitely higher consumption than I would have expected. Are you driving exclusively in stop-start traffic? If so, that would help explain your consumption, but even then, I’d expect it to be closer to nine or 10 litres per 100km, not 13.

On that basis, I’d be giving the engine a once over in terms of how its fuel-injectors are working and checking things like fuel filters and pump pressure. A car that is not allowing its engine to warm up properly can also use more fuel than it should, because the computer, sensing that the engine is cooler than it should be, richens the fuel-air mixture to compensate. The cause of that can be something as simple as a dud thermostat or a cooling fan that is not switching off when it should.

But the other potential piece of the puzzle could be related to your driving style. You claim that the engine never goes beyond 2500rpm, which could mean you are `lugging’ the engine; making it work too hard at too low a speed. Modern four-cylinder engines don’t mind a rev and, in fact, need to be revving beyond a certain speed to be in their happy, most fuel-efficient, zone.

You could argue the semantics of what is and isn’t a major failure till the cows come home and still not get any joy. But while I’d still be talking to the dealership, I’d also contact Holden’s Customer Service department and explain the situation to see if it will overrule the dealership’s call on this. The number to call is 1800 46 465 336.

Meantime, if the car is fixed and working properly, what’s the problem? You could get a brand-new car and have exactly the same thing happen, so where do you draw the line on what’s acceptable and what’s not? Had Holden refused to fix the car or done a botched job that still left the car with problems, it would be a different story, but if the car is back to brand-new, I would consider the problem to be solved. I’m tipping head office will see it the same way.

Clearly water is getting into the car and causing your problem, so the trick is to find where it’s getting in. For start, have a feel around the seats and carpets to see if you can feel a damp patch. That will help narrow down the entry point. So will locking the car up on a warm day and noting which windows fog up.

Once you’ve done that you can start looking closely at all the rubber seals around the windows and doors as these are a likely culprit. Believe it or not, even a simple leaf or twig stuck to the rubber sealing surface can allow rainwater in, and any little nick or tear in the rubber can do likewise. It might sound basic, but are all the windows closing properly? Does the car have a sunroof, as these are notorious for letting water in even when they’re closed?

If you can find a volunteer, have them sit in the car while you take a garden hose to it. If the leak is a bad one, they might be able to spot it. Other times, though, the car needs to be moving for the water to be forced or even sucked in.

You should also check the level of coolant in your radiator or overflow bottle. If the heater matrix inside the car is leaking coolant, you’ll get the same symptoms over time. The clue there is that if the heater is leaking, the level in the radiator will fall.

The Sorento seems like a pretty good choice. But don’t forget its cousin, the Hyundai Santa Fe which is also a great vehicle. On balance, though, the Kia seems a little better value and has a superior warranty. In fact, the Kia factory warranty of seven years/unlimited kilometres is an industry leader and makes for great long-term peace of mind.

If you’re happy with the way the Kia drives and works for your family, then there’s no reason not to make that your first choice.