Kimi Raikkonen has confirmed Ferrari will run a new engine upgrade this weekend, but has played down its significance.
Ferrari will bring the first of its in-season engine upgrades to Russia in the hope of unlocking more power on Sochi's long straights. Raikkonen said the decision had been made purely for performance reasons rather than a reliability issue on his existing engine.
"We have a plan, like we had last year, to make certain things at certain times, improve and bring new parts for some races," he said. "The plan is similar and we're following it, it will be a different engine, a new engine, but it's part of the normal progress throughout the year.
"Is it going to make an awful lot of difference? I don't know. There's nothing wrong with my engine, it's just a new spec. I don't know how it's going to be -- we'll see."
Raikkonen is currently fifth in the drivers' standings, but has four more points than he had at this point last year. Asked if he was happier with his start to the season in 2016, he said: "Obviously not... It could be an awful lot better, we had some struggles in the first few races but at least we got some points out of it.
"The aim is to always do better and that's what we'll try to do here. If we can do a normal weekend, without any issues, hopefully the end results will be better. It's early in the season, but we keep working and making progress."
Raikkonen said the objective for Ferrari is still to beat Nico Rosberg and Mercedes as soon as possible.
"He's one of the few drivers that has had very clean and good races. Obviously he's won all three of them pretty easily - good for him, obviously. We have to try and beat him, Mercedes and all the others. We just have to keep going and, as I said, it's the early part of the season and if the gap is quite big, there's a lot of races ahead of us."