Lotus will not run its rear wing 'device' at this weekend's Japanese Grand Prix after it failed to offer a significant advantage in Friday practice.

The system, often dubbed the double DRS, was fitted to the car for first time since practice for the Belgian Grand Prix, but again the team struggled to get it working properly. Kimi Raikkonen said a number of problems with the 'device' meant it would not be fitted for Saturday and Sunday.

"It worked a little bit but we're not going to run it," he confirmed. "Plus we had some other issue during the running so it probably didn't help to get the best out of it. But it's not going to make us really near the front if it would work 100%.

"It started well the first time that we tried, but with all the things going on it hasn't been as easy as we hoped. We're learning with it."

Raikkonen also suffered a KERS problem in second practice which meant he was not able to set a representative lap time. However, team-mate Romain Grosjean's sixth fastest lap means Raikkonen is optimistic Lotus will be more competitive this weekend.

"For sure it doesn't help because we lost quite a lot of track time and it's not the easiest place to get the car right. But if there's something positive it's that it happened today and not tomorrow morning. I think if we look at what Romain did today we were closer to the front here than we were at the last few races. Hopefully that's a sign that it's a bit better."

Raikkonen is third in the title race and said the main aim was to finish ahead of Fernando Alonso to try to reduce his 45 point gap to the championship leader.

"Hopefully we can score more points than Fernando. Even if we lose a place to Lewis [Hamilton] it makes no difference, we just have to try to gain on the front and go from there. At the next race we should have more new parts and we can aim for the bigger results."