Mercedes and Ferraris battle for F1 supremacy has ramped up at the Russian GP with both teams spending their first in-season engine development tokens. Ferrari drivers Sebastian Vettel and Kimi Raikkonen will race with new internal combustion engines in Sochi after the team spent three of the nine tokens they had left over from the winter.Meanwhile, Mercedes have used two of their 13 outstanding tokens on fuel system improvements, which their championship-defending works outfit and three customers teams - Williams, Force India and Manor - will all benefit from this weekend. However, none of the eight Mercedes-powered cars in question are required to fit fresh engines as the improvements come outside the sealed areas of the power unit. The world champions have also introduced a new oil from suppliers Petronas.Mercedes now have 11 tokens left to use over the remaining 17 races. Ferraris need for performance improvements are more acute with the Scuderia already over 50 points adrift of Mercedes in the Constructors Championship. The teams start to the season has been hindered by reliability problems, with Vettel and Raikkonen both registering a DNF apiece in the opening three rounds.It seems that Ferrari spent three of their engine tokens on combustion, which is half for performance and half for reliability, said Sky Sports F1s Ted Kravitz.That means Vettel is now on his third engine out of five for the season. We presume that the swapping around will only last so far and hell have to take a sixth. Raikkonen is on his second engine.Hopefully well see more for the neutral this weekend.Watch the whole Russian GP weekend - LIVE ONLY on Sky Sports F1. The race begins at 1pm on Sunday, with build-up from 11.30am. Or watch the race without a contract for £6.99 on NOW TV. Also See: Rosberg: Rivals will fight back Red Bull taking aim at Ferrari Shalom Luani Jersey . Vaives lawyer Trevor Whiffen claims the former 50-goal man wasnt provided with a copy of the claim beforehand and that he would not have agreed to the allegations made against the NHL had he been asked to review its contents. Nick Vannett Jersey . Speaking Thursday on TSN 1050 Thursday, the Leafs GM also touched on the questions surrounding the teams leadership and the struggles of his big-name free-agent signing. “Its not from lack of effort from the coaching staff. http://www.cheapseahawksjerseysauthentic.com/ . Already owning gold from competition in Vancouver in 2010, Loch posted a combined four-run time of 3:27.526. That included a track-record third run of 51. Justin Britt Jersey . The team also announced Tuesday that the Braves will wear a commemorative patch on the right sleeve during the season. The patch, shaped like home plate, carries the number 715, Aarons autograph and a "40th Anniversary" banner. Caleb Scott Jersey . The defending champion beat Gael Monfils of France 7-6 (6), 6-3, while second-seeded Andy Murray of Britain dispatched Edouard Roger-Vasselin, also of France, 6-3, 6-3. Making his first appearance since injuring his wrist a month ago, Del Potro had difficulty with his service games in the first set. OXFORD, Ohio -- Logan McLane and Michael Weathers scored 15 points apiece and Miami (Ohio) held off an IUPUI rally in the second half Saturday for a 71-68 win.Miami (5-5) led by as much as 21 but had to scramble to pull out the win after IUPUI tied the game at 68-all with a 3-pointer from Kellon Thomas with 29 seconds left. Rod Mills Jr. put Miami back on top with a jumper at the other end, then McLane hit 1 of 2 from the line with three seconds left to pad it.IUPUIs Matt OLeary misseed a 3-pointer just ahead of the buzzer.ddddddddddddMarcus Weathers got 13 points to make it his fourth straight game in double figures and Mills finished with 11 for Miami.Trailing 59-38 in the second half, IUPUI (3-7) rallied with a 23-3 run that included 3-pointers from T.J. Hend