The odds are shortening that an SUV will replace the Commodore on local production lines - and it could be spun off the Cruze small car platform.

The replacement, which is likely to be the next generation of the Captiva, is expected to replace the Commodore in about 2018.

Holden managing director Mike Devereux would not confirm what the potential Commodore replacement would be but said it would need to be a vehicle that was capable of being a top 10 seller in the local market.

At the moment, the Commodore and Cruze are in the top 10, but with Commodore sales dropping at an alarming rate it is unlikely the one-time family staple would be in the top 10 by the end of this decade.

That leaves either an SUV or a one-tonne ute. Holden has a platform that does both - it has just launched a seven-seat SUV that is based on the Colorado ute platform - but this seems an unlikely option given that the vehicle is a low-cost, budget price option.

Mr Devereux refused to reveal whether an SUV spun off the Cruze underpinnings would be built locally but said that could constitute the much talked about second platform for the company if it was built.

"There is consideration to building two platforms at the end of this decade. I've been on record as saying that we'd be pretty stupid silly not to build a small car given how big that segment is," he says.

"There are SUVs planned for small car platforms but I don't think that would infer anything in terms of what our decision-making process would be for that second vehicle line.

"In order for us to be able to make the Adelaide plant work economically we have to pick two pretty much top 10 vehicles. There's no room for error."

He said the fragmentation of the market in recent years made it much harder to get a volume seller. There were 80 SUV models and 40 small cars on the market alone, and the company needed to sell roughly 1800 cars a month to make local production viable.

"The more you have to compete with the more risk there is," he said.

That made it a tough ask for an SUV that would sell in sufficient numbers to sustain an assembly line, although he wasn't ruling it out. The Mazda CX5 was the top selling SUV with a little more than 1800 sales last month, so any local SUV would have to "knock it out of the park" on sales.

He didn't rule out the Commodore being the second vehicle, and said the VF Commodore would answer the question of whether the car could remain a top 10 seller. Export potential would also play a part in overall volumes.

"Exports will make sense if the dollar is right," he said.

He ruled out the possibility of building the mid-size Malibu sedan in Australia.