Porsche's engineering cheif Wolfgang Hatz talks to Top Gear UK, and this is what he has to say!

The turbocharger continues its march across some of our most cherished engines. The next batch of Porsche 911s will get blowers for the mainstream models, Porsche's engineering chief Wolfgang Hatz told us at the Detroit show.

"You have to respect legal requirements [for lower CO2], so yes we're thinking turbos for standard 911s. You can't afford to keep an engine for 10 years any more."

He had earlier explained that the new 911 GT3 RS, which will be launched in March at the Geneva show, features an all-new very powerful naturally aspirated engine. A version of that engine, with turbos but less power, strangely, will be what's in the facelifted 911s in 2016.

"Emissions are important for us," said Hatz, "And we will reduce faster than the industry. Every new model will have lower CO2 than before. There aren't so many technologies to do it. If you look at euro per g/km then it's turbo. Then at the end of the decade electrification has to be the next huge step." Does that mean a hybrid for the all-new 911? "Yes." With expertise from the 918 and 919 racer, Porsche is in a good position.

He also acknowledged that Porsche is developing a four-cylinder turbo for the Cayman and Boxster ranges from 2016. Is it a flat four? "It's not an in-line four or a V4." Will it go into the 911? "Never. That's always a flat six." Phew.

Again in pursuit of better economy and performance, Hatz said Porsche is working on an all-new V8 for the next generation of Cayenne and Panamera. These cars also have to get lighter. He said the objective for the next Cayenne V6 is under two tonnes, even though it will add equipment. At the moment it's nearly 2100kg.

But you don't want to know about base-model SUVs, you want to know about hot semi-racers.

He confirmed there is a Cayman GT4 coming this year. He said it's developed by the motorsport department who do the GT versions of the 911. It will have about 400bhp, and be usefully lighter than a standard car. It's more hardcore than the old Cayman R, he said, and is "for customers who want an entry race car."

And the 911 GT3 RS will be at the Geneva show. Hatz said the existing GT3 surprised people by how civilised it is. He says the GT3 RS is a bigger jump from the GT3 than there was in the 997-generation GT3 to GT3 RS. So we're looking at a pretty rabid car.

But if that's not enough, what about people who want more: a GT2 with turbos? "We have so many 911 variants," - this was minutes after they'd launched the Targa 4 GTS - "but customers do ask for a GT2, and we will decide."