Lotus is set to stick with is new Coanda-effect exhaust for the remainder of the Korean Grand Prix weekend after the team ran the part for the first time in Friday practice.

Kimi Raikkonen ran with the part in the two Friday sessions en-route to the tenth quickest time and trackside operations director Alan Permane said the team was now to keep the part on the car for the remainder of the weekend.

"We're happy with how the new exhaust worked from a performance perspective and now need to assess if there are any potential reliability implications due to the hot exhaust gas running in different areas than usual," he said. "Early impressions are certainly good and we expect to retain it for the rest of the weekend with Kimi.

"Romain complained of a little too much oversteer and with Kimi there's still potential with the setup, especially as we learn more about the new exhaust. Both drivers reported that they were very happy with the balance of the car when on high fuel loads and degradation levels look manageable from the tyres so it's been a productive first day."

Raikkonen himself however said it was too early to comment on how much performance the new exhaust will provide until the data collected has been fully explored.

"The circuit is okay; it's surprisingly bumpy in some parts but it's quite different from other places we race," he said. "It's difficult for me to say about the exhaust until I've sat down with the engineers and gone through the data. We'll try to improve the car for tomorrow as it wasn't very easy to drive and get a good lap today. Let's see if we can get it completely right and maybe we can be in the top five in qualifying."

Team-mate Romain Grosjean was a tenth of a second further back on the times but wasn't completely happy with how his weekend had started.

"It's not been the easiest day," he said. "I think we still have some work to do with the car to get the best out of the tyres so tomorrow morning will be important. The track is interesting but it's not been so hard to learn. The trickiest part is definitely turns eleven and twelve which are not easy to get exactly right but overall it's not too bad.

"On the positive side we've had a good amount of time learning the circuit and gathered a lot of data, so hopefully we can analyse things overnight and see an improved performance by the time we get to qualifying."