As he launches the most Lotus-ish Lotus ever, the super-light and fighting-fit 3-Eleven, Lotus boss Jean-Marc Gales takes some time to justify to TopGear what must be the least Lotus-ish Lotus ever: the upcoming, Chinese-built SUV crossover.

The SUV will be the result of a joint venture Lotus signed last year with Goldstar Heavy Industrial of Quanzhou city. Mind you, if it ever goes on sale in Britain, it won't be until about 2022. So if you furiously judge this a Lotus sell-out, you still have several years for your anger to subside.

Of course Gales believes that making an SUV will bolster profit. Building an SUV is standard operating procedure for a sports-car company these days, right?

And in most of its 63 years, Lotus has shown the opposite of profit. But Gales reckons an SUV will do something else too: improve the sports cars.

Seriously, how can an SUV match Lotus's values? "If Colin Chapman was alive I believe he would have done one," says Gales. "It will be the size of a Porsche Macan but only 1600kg, and will be the most agile and fastest of that class on a track. Lamborghini is doing a SUV like that in their segment, we can do it in our segment."

Gales repeatedly stresses the weight issue. "It's logical for us to make one in the Macan segment - the rest are all two tonnes, even a BMW X3. They take a normal car platform with big tyres and brakes and transmission. We will use a four-cylinder engine."

That'll be Lotus's existing supercharged Toyota-derived unit, though a diesel will be needed for Europe. "We'll take 250kg out, so we can have smaller brakes, we can use Evora seats," Gales adds.

We always thought the appeal of SUVs is they feel heavy and robust. Still, let's give him the benefit of the doubt. Maybe a chink of a sales opening exists for something lighter.

The vehicle will be Lotus-branded but built at a new joint-venture factory in China, aimed at the vast and growing Chinese market for crossovers.

Manufacture there is an exercise in red tape. The procedure is that the authorities grant a manufacturing licence only after the prototype has been built and the business plan written. Those two things are happening now, Gales says.

He adds sales of the SUV should begin in China at the end of 2019 or in 2020. If that goes well, it might come here afterwards. "We have protected the package and technology for Europe."

It originates here too. "It's being designed and engineered and prototyped at Hethel," he says. "We are evaluating two full-scale design models at the moment. They are very sporty and they look very Lotus. They have a modern Lotus nose, and a hint of the 1974 four-seat Elite [pictured above] on the side. They look lightweight."

But Lotus doesn't only make cars noted for light weight and brilliant handling. It has also traditionally been noted for making cars that aren't entirely watertight, that have untrustworthy electrics and wonky panel gaps.

For a five-door SUV as opposed to a little roadster, this sort of boring housekeeping will be utterly vital.

I put this to Gales and he is eager to agree. He points at the door seals on an Exige. "They drive me crazy," he spits. "We have just hired a new chief engineer for body and closures. We are working with the suppliers to make those seals very differently. We have a new electrical chief too."

He takes me around the Evora 400, pointing out the places where the finish and ergonomics have been dramatically improved. And, with admirable candour, the ones where they still aren't good enough.

"Our warranty costs are now just one-third of what they were two years ago," he claims.

So if Lotus can get the quality of the SUV to any sort of acceptable level, the sports cars are bound to gain. But he goes further. "We can use parts, such as climate control units, in the SUV which will be better for the next generation of sports cars."

I say that an air-conditioner for a five-seat SUV will be too big and heavy for a two-seat sports car. He counters: "We could use two small ones in the SUV. We can use new instrument panel parts from the SUV in the sports cars. They won't make the sports cars one gram heavier."

At which point, TopGear.com commenters, you'll point out that we've heard all sorts of promises from Lotus bosses before. And they've often been unfulfilled.

Still, Gales isn't only a proper petrolhead but a veteran of the grown-up motor industry, with high-level experience in Mercedes-Benz, VW and PSA. He joined Lotus in May 2014 and since then the changes he promised have mostly happened. On time.

He has improved Lotus's manufacturing, quality and distribution, so the cars are selling much faster these days. Lotus's wholesale deliveries were 1296 in the year to March 2014. In the year to this March they were 55 percent up, at 2015 cars (a nice coincidental number).

Even so, the idea of making a Lotus away from its traditional sports-car comfort zone seems like a watered-down version of the previous ultra-ambitious line-up proposed by previous boss. Is this just Bahar-lite?

"No. We will remain a sports car company," states Gales. He promises those cars will always be built at Hethel, too. "We have done the 3-Eleven, the Evora 400."

And there's more, coming at a pace Lotus would once have found dizzying. "The [2017] Exige will be faster, and have bigger wheels and brakes, even though it has better air-conditioning and infotainment, and lower sills for easier entry. The Elise will have a restyled front clamshell." This change will be made by a cheaper but better manufacturing process.

"These cars will keep getting faster and lighter," continues Gales. "There will be an Evora 400 Roadster, with twin carbon fibre roof panels that stow in the front and weigh just 3kg each."

He comes back to the 3-Eleven and grins. "I also have a plan for a 4-Eleven in two years..."