The Subaru BRZ might be a one-hit wonder.

The long-term future of the Toyota 86 twin has been placed under a cloud because Toyota is evaluating a potential change in partnership for its next-generation sports coupe.

The Japanese car maker is currently collaborating with BMW on the development of a high-performance sports car to sit above the 86. The chief engineer responsible for both, Tetsuya Tada, told Drive the program with the German brand could be expanded to include the next 86.

"Maybe, but this is not decided at the moment," Tada said when asked if Subaru's parent company, Fuji Heavy Industries, would remain involved in the development of the 86.

When quizzed on whether BMW could take over its role in the partnership, he said: "That is one possibility."

If Toyota were to expand its cooperation with BMW at the expense of Subaru it would be shunning a company it partially owns. Toyota owns a 20 per cent stake in Subaru's parent company, Fuji Heavy Industries, something that helped in creating the 86 and BRZ models on sale today.

Toyota are looking at ending its partnership with Subaru, which could spell the end for the BRZ.

Whatever the case, the next Toyota 86 is likely to be more radical than today's relatively simple concept.

Tada has reaffirmed his engineering team are examining a number of alternative powertrain solutions, including potentially replacing the boxer four-cylinder engine with an in-line engine.

"So far, I have no idea," he said in response to whether the boxer engine layout would be retained.

"This is also something we are studying. The trend of powertrains is of course downsizing and turbo charging, but my opinion is to retain natural aspiration in the future."

He did, however, all but confirm it will have some form of electric assistance to improve its power output as well as reduce fuel consumption, hinting that the supercapacitors used in the company's Le Mans sports car best match the lightweight philosophy of the car rather than heavy battery packs.

Toyota are looking at ending its partnership with Subaru, which could spell the end for the BRZ.

"Maybe next generation 86 must have some kind of eco technology like racing hybrid," he said.

"We raced at Le Mans with this and that is the reason why we challenge ourselves with this technology."

Before then, Tada is studying a number of options to improve the current 86 in time for its mid-life facelift due in 2015.

Among the possibilities to improve power is a larger capacity boxer engine or upgraded exhaust and intake systems derived from the Gazoo Racing car that won its class in last weekend's Nurburgring 24-hour race in Germany.

However, Tada also hinted that simply modifying the car's final drive ratio is an affordable way to make it feel more spritely.

"Some day we are aiming to do big update and change," he said.

"Every 86 enthusiast has been asking question on more power and we are studying now for the answers."

Right now though, a mildly updated 86 will go on-sale in Australia next month with a few additions to its sparse list of features, including a shark fin antenna, a digital speedo added to the base-model GT and a reverse camera fitted on the top-spec GTS.

Toyota Australia has yet to confirm whether the update will create a price rise for both models, but company spokesman Steve Coughlan could not rule it out.

Subaru has hinted at other variants it could do of the current BRZ, most recently with the Cross Sport concept.