Your questions answered: can I boost the power in my BYD Shark?

In this edition of Your Questions Answered, we unpack why one BYD powertrain isn’t necessarily like the other, tackle another key fob conundrum, and ponder whether bigger really is better for wheels.

Got an automotive question but you don’t know where to find the information you need? Never fear, email us here at editor@carsales.com.au.

I just bought a used car (2009) with remote central locking system, but it keeps locking itself without touching the key.

I unlock it with the key fob, open the door to load the car up, only to hear it lock itself randomly – meaning if I was to accidentally close the door with the key in the car, I will potentially be locked out.

Is it the car or is it the key fob? – Alex

Answer: Hey Alex, this is a tough one. If I had to hazard a guess, your car isn’t as original as it once was, which may have had a knock-on effect on how the key interacts with the car.

In fact, given your car is now old enough to get its own driving licence, there could be several reasons.

One possible culprit? Water – it's notorious for sneaking into the darndest places and could be causing an intermittent short that trips your unlock circuit.

The fob itself might not be a factory original and could be showing its age. A quick battery swap might just do the trick.

If you still have a manual key option, I recommend getting a spare or two cut and stored somewhere accessible until an auto electrician can give you a better idea of what’s going on.

You could crack a window to avoid getting locked out, but technically, leaving your car unsecured –even in your own driveway – is against the law in several states (cue eye roll).

I just read your review on the new Denza B5 4x4, which I noted had more power and torque than the BYD Shark.

Does it have the same engine and gearbox as my six-month-old Shark? And does that mean I can potentially access the same power and torque? – Bob

Answer: Hi Bob, you’re right to suggest that the BYD Shark ute and the forthcoming Denza B5 (essentially an upmarket SUV-bodied version of the Shark) share roughly the same powertrain, which is based around a turbocharged 1.5-litre petrol engine and a pair of electric motors.

I say ‘roughly’ only because of the disparities in outputs. Take the petrol engine: the Shark produces 135kW while the B5 is quoted at 145kW – despite being the same size.

The front electric motor in the Shark makes 170kW (compared to 200kW in the B5) and the rear motor delivers 150kW (versus 285kW in the B5). Combined, the Denza’s outputs total a claimed 505kW and 760Nm, while the Shark is rated at 321kW and 650Nm.

In short, it’s a hard no. Even if you ignored the warranty implications and somehow find someone capable of recoding the BYD’s various systems, my educated guess is that the B5 uses entirely different – and larger – electric motors to achieve its outputs, rather than simply scaled-up versions of those found in the Shark.

Finding the 10kW from the petrol motor might be achievable via more conventional means, but it really wouldn’t be worth the effort.

It’s also worth noting that the B5 is around 200–300kg heavier than the Shark, which helps explain its higher factory power and torque outputs.

What should I watch out for? – Dave

Answer: Hey Dave, thanks for tuning in. Going up in wheel size is eminently doable, but there are a few things to take into consideration.

Firstly, check in with your insurance provider. Surprisingly, most are fine with nicer wheels – as long as you stick to a prescribed formula. Going up a rim size is known as a “plus-one” upgrade (for example, from 16-inch to 17-inch), and going up two sizes is “plus-two”.

Most insurance mobs are okay with plus-one, while more specialist providers may approve with plus-two setups. In your case, depending on the model year, sliding an 18-inch rim should be straightforward.

Next thing is overall size. You don’t want to exceed the overall wheel/tyre diameter by much (if any) between your old and new wheels. Therefore, the new rim will need a lower profile tyre to ensure that the diameter doesn’t grow too much.

Width and offset are key considerations too. Taller rims are generally wider, and offset – the distance between the wheel’s mounting surface and its centre line – is crucial to ensure your new wheels don’t rub against the wheel arches or the inner edges of the wheel wells.

There’s a plethora of online resources to help guide you, but my go-to is willtheyfit.com. It lets you plug in all the relevant specs to check whether the rims you’re eyeing will actually suit your car. Good luck!

The views stated in this advice column are advisory only. Questions may be edited for clarity and length.

Got an automotive question but you don’t know where to find the information you need? Never fear, email us here at editor@carsales.com.au.

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