LONDON (AFP) - England captain Andrew Strauss challenged his side to improve their game still further after they completed a 4-0 whitewash of India. England, who earlier in the series had replaced India at the top of the ICC's world Test rankings, finished with a flourish, winning the fourth Test by an innings and eight runs to wrap up victory before tea on the fifth day in front of a capacity crowd at The Oval here on Monday. Off-spinner Graeme Swann hurried India to defeat with a return of six for 106 after Sachin Tendulkar had fallen nine runs short of becoming the first batsman to score 100 international hundreds. India, who had looked as if they might at least make England bat again during a defiant fourth-wicket stand of 144 between Tendulkar and Amit Mishra (84), lost their last seven wickets for 21 runs to be 283 all out. England's next Test is not until early next year when they face Pakistan in the United Arab Emirates. Although for several players the imminent one-day series against India means there will be little respite from England duty, Strauss -- who has retired from limited overs internationals -- will have plenty of time away from the spotlight even if he will still play for Middlesex in the remainder of the English season. Asked about the glow of England's latest innings victory, Strauss told reporters: "I think it will keep me nice and warm, yes. "We've had to put a lot into it and certainly in this game," he added after a victory that left England with an unbeaten Test record for 2011 of played eight, won six and drawn two. However, Strauss warned that the players should not rest on their laurels. "The greatest pitfall is that feeling that you've done it all, therefore you're not willing to put in the hard work. I'd be very disappointed if we fell into that trap." And Strauss knows that whatever the ICC rankings may say, there will be plenty of cricket followers who will want to see how England perform in Asia before accepting they are the world's top Test team. "Winning away from home is always more difficult," said Strauss. "We should be competitive in our conditions against anyone in the world. "Away from home is harder, so we're going to have to challenge ourselves to improve away from home -- and then it's about maintaining standards and performance, and being consistent.