Isuzu MU-X 2021 Problems

It's true that new engines can be 'tight' and this can lead to higher fuel consumption than they achieve with a few more miles on board. And since you're almost at the 30,000km mark now, why not try the dealer's advice and see if things start to improve.

The MU-X was never the most fuel efficient vehicle in its class, but even so, 12.2 litres per 100km on the highway sounds a little excessive (although not as much as you might think). I'd expect this vehicle to return highway fuel economy figures closer to 10 litres per 100km or maybe a bit less.

However, there are several factors that might be skewing your results. The bluff aerodynamics of a vehicle like the MU-X mean that even a slight headwind can increase consumption. So can the addition of accessories such as a bull-bar and roof racks. A set of roof racks on their own can add a litre of fuel to every 100km travelled, and that's if they're not loaded. Throw a spare tyre and some gear up there and it's even worse.

Bigger (taller) tyres can also increase fuel consumption, and so can running your tyres at too low a pressure.

It sounds very much like the transmission is confused electronically or has a problem with its valve body which is supposed – in conjunction with the computer – to make decisions about what gear the transmission should be in. Perhaps it's as simple as a dodgy electrical connection somewhere and the impact of potholes or buffeting from passing trucks is causing a short-circuit somewhere.

The first piece of advice, however, is to not drive the vehicle any farther. You not only risk damaging the transmission, but it's also dangerous to drive a vehicle that might suddenly select the wrong gear at random. The second piece of advice would be to take the vehicle to a dealership and have its computer scanned to see if any fault codes have been recorded. If your local dealer doesn't want to know, take it straight to head office and contact Isuzu's customer service division.

The good news is that your vehicle is still under the factory warranty, so make it Isuzu's problem, not yours. Just make sure that the behaviour has been logged as a problem, at which point it's classed as a pre-existing condition and Isuzu is still obliged to fix it even if the warranty runs out.

I presume your MU-X is a first-generation model, not the second-generation that launched in mid-2021? The latter is engineered for a WDH, but the former is not.

Many people think a Weight Distribution Hitch (and also known as load levelling bars) will alter a caravan’s level or otherwise. But the truth is that these are really only designed to transfer some of the tow-ball loading to the tow vehicle’s front axle. `Level riders’ as they are known are more of the same. Many car-makers do not recommend or even permit the use of these hitches, so Isuzu is hardly alone there.

The problem you face in using them in direct contravention of Isuzu’s own advice is that, if there is a problem on the road, you might find your insurance company will attempt to disown you on the basis of having ignored that official advice.

When the new D-Max arrived in 2020, the big improvements included a step up in standard equipment and a big leap forward in refinement and ride quality. The engine and driveline, however, was carried over from the previous model, so performance and driveability were similar.

With that in mind, you can probably expect the all-new MU-X to offer a similar hike in standard equipment terms. But unlike the D-Max with its rear leaf springs, the MU-X already features coil springs all around, so there may not be quite the same boost to refinement or ride quality. That said, it’s unlikely Isuzu would go backwards in this department. If you can live without the creature comforts, then a run-out deal on the old model seems like a pretty good idea. It really all depends on how much importance you place on having the latest and greatest.