The hybrid car options are expanding and some of the newer entrants like the Chinese BYD brand, are embracing the hybrid engine technology.

This week I’ve compared two relatively new hybrid cars, which may not be entirely similar but offer similar technology: from Renault and the new generation BYD offering.

The Renault Symbioz is a spacious car with good boot space extending to 1582 litres with the rear seats folded but no spare wheel is included.

Renault has introduced a new car in the mid-size Symbioz SUV, while BYD launched its first hybrid car in the shape of the slightly bigger Seal U also an SUV.

So, we have an older established Renault brand delivering new hybrid technology in a brand-new model, the Symbioz versus a new car BYD brand, that’s less than 10 years old and competing with impressive hybrid technology, as if it’s been around forever.

The specification table in this article tells some of the story, but buying and owning a new car is not just about the numbers on the page.

The Renault Symbioz took me across more than 700km on a full tank of petrol and the transition from petrol driving the electric hybrid as seamless all along the way.

Despite that, the car lacked the comfort levels that you expect from a Renault.

The dash design for the Renault Symbioz is modern and stylish, while the designers opted for a centre mounted control of the automatic gearbox functions.

There was noticeable vibration and road noise in the car that could not have been solely a function of the tyres fitted. This made the drive less pleasant than I would have expected.

On the inside, the car is attractively designed and has a clear and modern layout.

On a safety front, the Symbioz also surprises in achieving only a 4-star Euro NCAP rating, when almost every other Renault car produced in the last 10 years has been a five-star safety winner.

Not so at the Chinese HQ of BYD (Build Your Dreams) car brand. They have offered their first hybrid car in the shape of yet another SUV; this one called the BYD Seal U model.

This car has the first internal combustion engine that we have seen from the BYD brand, and they have certainly got their engine manufacturing right.

BYD uses a slightly smaller 1.5 litre petrol engine in the U Seal version, while Renault uses a 1.6 litre petrol engine to power its hybrid system.

The Seal U is a plug-in hybrid (PHEV), while the Renault Symbioz is called a HEV, or a mild hybrid where the engine charges Renault’s significantly smaller battery pack on the move.

The BYD version delivers more power and better acceleration performance. It’s also noticeably smoother on the road and more comfortable to drive.

This car has a lower emission level, even though it is more powerful.

The end result is not exactly a more fuel-efficient car, but when the bigger fuel tank size is included, there is similar range between the two in this comparison.

That’s partly explained by the fact that the Seal U is almost 500kg heavier and that’s a function of the PHEV battery pack that gives up to 80km of full electric driving before the smooth engine seamlessly takes over.

The BYD Seal U came on Continental 235/50 R19 tyres that were very smooth in delivering quiet power on the road.

The BYD Seal U is a smart-looking car in the conventional SUV design sense. It’s not particularly stand outish in the car park, while the Renault Symbioz has a more obvious identity.

I took the BYD Seal U over a 600km test route and found that its range came closer to its theoretical expectation than that of the Renault Symbioz. It is a very comfortable car to drive and other than a large and somewhat distracting infotainment screen, there is no challenge to driving this car.

Final choice

On the face of it, these are two hybrid cars, but they differ in that the Renault Symbioz has a system where you just fuel the car, and it does the hybrid work after that.

The BYD Seal U requires a plug-in every so often to maximise its range potential, but you can still live with it relatively comfortably as a petrol-only car.

There is the penalty however of a larger and heavier battery in the BYD that does add over 500kg extra weight that will compromise economy a little while that’s softened only by the bigger fuel tank, meaning less fuel top-up stops.

These are two new cars, so there is no cost of ownership data available to analyse their running costs just yet. The Renault Symbioz is noticeably cheaper both in the south and N. Ireland, while the more spacious BYD Seal U is more expensive in both markets.

Renault Symbioz entry prices start at €36,995 or £29,295 in N. Ireland for the Techno versions, while the BYD Seal U starts at €42,150 or £31,569 in N. Ireland for the Boost versions.

I would pitch for the BYD Seal U based on a more comfortable drive, more so because I felt that the Renault Symbioz could have delivered more.