Porsche has managed to resist electrifying its 911 coupe for as long as possible, but even this iconic sports car has to relent to a changing automotive landscape. This year, a few sightings of the upcoming 911 hybrid have taken place, and Porsche has already confirmed that a heavier plug-in hybrid system won't be used.

We now have new photos of the updated 991 GTS hybrid, the first time that the GTS has been spotted testing as a hybrid. Having already driven the gas-only GTS with its 473-horsepower flat-six engine and finding its powertrain to be nearly flawless, one can only imagine how good the GTS hybrid will be.

Pictured at the Nurburgring, this 911 GTS sports the giveaway yellow sticker on its rear window that identifies it as a hybrid. Unlike lesser Carreras, we can also see the larger dual tailpipes and the center lock wheels that are associated with the GTS. This 911 GTS has the same front bumper as an earlier 911 hybrid we spotted, but at the back, we can see the rear wing in its extended position. Besides the different wheels and small fog lights in front, not much else differs from the regular 911.

As mentioned, the current GTS makes 473 hp and 420 lb-ft of torque. It can reach 60 mph in as little as 3.2 seconds with the dual-clutch PDK automatic transmission and Sport Chrono Package or 3.9 seconds with the manual.

While Porsche hasn't released the technical specifications of the 911 GTS hybrid, we know that the goal will be to increase performance, not necessarily to chase greater efficiency. It will use technology inspired by previous Porsche projects like the 919 Hybrid endurance racing car, so the new GTS hybrid could either have an electric motor as in a traditional hybrid or a mild-hybrid system. We don't expect outputs to be much higher than 500 hp so as not to encroach on the GT3 or 911 Turbo's turf too much. A hybrid 911 Turbo was spied previously, though.

What the hybrid system will likely do is elevate the driving experience of the 911 by filling in torque gaps when changing gears, while providing an extra hit of low-down torque for faster starts.

It's not clear whether the 911 GTS hybrid will come in both RWD and AWD '4 GTS' variants, but this information will hopefully be revealed by the automaker soon. As we've seen with the Panamera E-Hybrid, Porsche knows how to build a powerful hybrid that is still engaging to drive.

For the 911 hybrid, weight management is the major factor that becomes more important than for the Panamera luxury sedan, though. This is even more important in the GTS, which is traditionally a sportier variant tuned for occasional track use.

With Porsche having been seen testing 911 hybrids for over a year now, we hope to learn more about these models before the end of the year.