For 2007, Sébastien Loeb returned as an official Citroën driver, with the new Citroën C4 WRC.
He won the 75ème Rallye Automobile de Monte-Carlo, the first race for the new C4, following that with a solid second place after Grönholm, in Sweden, to set a two-point lead over the Finn after two of 16 rounds.
At the first Rally Norway, Loeb went off and lost eight minutes during SS12 while chasing Grönholm and the leader, Mikko Hirvonen.
On the next stage, he made another mistake and lost nine minutes.
He eventually finished 14th in the rally and dropped to third in the championship standings.
He won 8 of the 18 stages in this rally.
Loeb won the next rally, the 21º Corona Rally México, 55.8 seconds clear of Grönholm.

He then followed this success with his third and fourth season victories on the Portuguese and Argentinian rallies.
Characteristically, he was once more to be found in the lead on the seventh round, the Rally d'Italia in Sardinia.
On new stages on the final leg to those of the previous year, however, Loeb was once more to lament error and the surrender of probable victory, this time after crashing and breaking his car's suspension in a ditch.
He left the lead in the hands of Grönholm, who won to propel himself seven points ahead of Loeb at the top of the championship standings.
A second loss to the Finn in as many years on the Acropolis Rally then extended the deficit to nine points over the championship's summer break.

Loeb occupied his recess by, amongst other engagements, competing in the Shell Donegal International Rally on 15, 16 and 17 June, partially as preparation for the coming Rally Ireland World Championship round that November.
He scored a comprehensive victory, albeit only after being given a scare by the pace of tenacious private Subaru-driver Mark Higgins, who had a 45-second lead at the end of day one.
Punctures afflicted upon his rival eventually settled the contest.

Ambitions of finally scoring victory on Rally Finland proved once more unrealised, with Loeb relegated to third place behind the pacy natives Grönholm and Hirvonen.
Rallye Deutschland, as was traditional, differed somewhat.
At the scene of his first victory and on a rally where he had never subsequently lost, Loeb was left unexpectedly to fend off the challenge not of the Finn, but of a privateer, his one-time teammate and championship returnee François Duval.
He eventually triumphed and reduced some of his championship points deficit.

A very close battle on the gravel stages of Rally New Zealand ended with the second closest win in WRC history – Loeb finished only 0.3s behind his main rival.
The next two rounds allowed the French driver to regain some points, as he won both tarmac events – Rallye Espana, where his teammate Dani Sordo took second place and two points from Grönholm, and Rally France.

Rally Japan was another dramatic event – Loeb got the chance to take the lead in the Championship after Grönholm's early mistake, but he was unable to, as his co-driver's mistake caused the C4 to go off the road on one of the stages of second leg.
Both drivers ended with no points after finally retiring from the event.
In Ireland, during 1st Rally Ireland almost the same happened – Marcus Grönholm overcooked a slippery right corner on one of the early stages, trying to keep a fast pace, and had to retire from the rally.
Loeb made use of his rival's mistake and, by making no major mistakes, although having some suspension-related problems with keeping pace at the beginning, he added 10 points to his account, moving ahead of the Finnish driver just one round before the season's end.
In Wales he was not fighting for the win, focusing mostly on securing his advantage, finishing the event third – on 2 December 2007 Loeb became World Rally Champion for the fourth time in a row.
For 2007, Sébastien Loeb returned as an official Citroën driver, with the new Citroën C4 WRC. He won the 75ème Rallye Automobile de Monte-Carlo, the first race for the new C4, following that with a solid second place after Grönholm, in Sweden, to set a two-point lead over the Finn after two of 16 rounds. At the first Rally Norway, Loeb went off and lost eight minutes during SS12 while chasing Grönholm and the leader, Mikko Hirvonen. On the next stage, he made another mistake and lost nine minutes. He eventually finished 14th in the rally and dropped to third in the championship standings. He won 8 of the 18 stages in this rally. Loeb won the next rally, the 21º Corona Rally México, 55.8 seconds clear of Grönholm.
He then followed this success with his third and fourth season victories on the Portuguese and Argentinian rallies. Characteristically, he was once more to be found in the lead on the seventh round, the Rally d'Italia in Sardinia. On new stages on the final leg to those of the previous year, however, Loeb was once more to lament error and the surrender of probable victory, this time after crashing and breaking his car's suspension in a ditch. He left the lead in the hands of Grönholm, who won to propel himself seven points ahead of Loeb at the top of the championship standings. A second loss to the Finn in as many years on the Acropolis Rally then extended the deficit to nine points over the championship's summer break.
Loeb occupied his recess by, amongst other engagements, competing in the Shell Donegal International Rally on 15, 16 and 17 June, partially as preparation for the coming Rally Ireland World Championship round that November. He scored a comprehensive victory, albeit only after being given a scare by the pace of tenacious private Subaru-driver Mark Higgins, who had a 45-second lead at the end of day one. Punctures afflicted upon his rival eventually settled the contest.
Ambitions of finally scoring victory on Rally Finland proved once more unrealised, with Loeb relegated to third place behind the pacy natives Grönholm and Hirvonen. Rallye Deutschland, as was traditional, differed somewhat. At the scene of his first victory and on a rally where he had never subsequently lost, Loeb was left unexpectedly to fend off the challenge not of the Finn, but of a privateer, his one-time teammate and championship returnee François Duval. He eventually triumphed and reduced some of his championship points deficit.
A very close battle on the gravel stages of Rally New Zealand ended with the second closest win in WRC history – Loeb finished only 0.3s behind his main rival. The next two rounds allowed the French driver to regain some points, as he won both tarmac events – Rallye Espana, where his teammate Dani Sordo took second place and two points from Grönholm, and Rally France.
Rally Japan was another dramatic event – Loeb got the chance to take the lead in the Championship after Grönholm's early mistake, but he was unable to, as his co-driver's mistake caused the C4 to go off the road on one of the stages of second leg. Both drivers ended with no points after finally retiring from the event. In Ireland, during 1st Rally Ireland almost the same happened – Marcus Grönholm overcooked a slippery right corner on one of the early stages, trying to keep a fast pace, and had to retire from the rally. Loeb made use of his rival's mistake and, by making no major mistakes, although having some suspension-related problems with keeping pace at the beginning, he added 10 points to his account, moving ahead of the Finnish driver just one round before the season's end. In Wales he was not fighting for the win, focusing mostly on securing his advantage, finishing the event third – on 2 December 2007 Loeb became World Rally Champion for the fourth time in a row.
Sébastien Loeb