The Cottagers play Norwich at Carrow Road on Saturday, with the loser potentially dragged into the relegation mix.
"If you leave it until the end of the season you've always got a problem; you don't want that," Jol said.
"What I always say is get to 35, 36 points as soon as possible, before the last couple of months of the season.
"We need four, five wins, and 40 points is the focus and target for us.
"I have been in this business longer than most managers and abroad you can say the bottom three at winter are likely to go down.
"But in England there are always surprises."
Fulham have three wins in eight games in 2013, are 13th, level on points with the 14th-placed Canaries, and, on 28 points, seven clear of the relegation zone.
But Jol is wary of Premier League precedent, with Birmingham relegated in the season when they won the Carling Cup and Blackpool going down after challenging for Europe earlier in the same 2010-11 campaign.
"With the amount of points we've got now, you go down," the Dutchman added.
"You need fighting spirit in every game. This is the highest level and we want to get out of trouble as soon as possible, like seven, eight, nine other teams.
"You need very good spirit to do that and if you look at the other teams, they've certainly got that. If you look at the likes of Reading, winning games, Southampton, looking good, and, of course, Norwich are dragged into it.
"Everyone is still aware of the fact they need to win as soon as possible."
Fulham lost 1-0 to Manchester United last weekend in a match which descended into darkness for a short spell due to a floodlight failure. An investigation is ongoing.
Bulgaria striker Dimitar Berbatov missed out against his former club with a hamstring problem and will undergo a fitness test to determine if he can play at Norwich.
"I think and hope that he will be in the squad," said Jol, for whom Mahamadou Diarra (knee) and Kerim Frei (pelvis) are confirmed absentees.
"If not, Urby (Emanuelson) will probably start. In an ideal world, I don't think he will start."
Emanuelson was one of three deadline day arrivals after signing on loan from AC Milan.
Stanislav Manolev and Eyong Enoh are unavailable as they wait for their work permits, but Steve Sidwell (knee) and Kieran Richardson (calf) are available again, bringing much-needed Premier League experience.
"That is the most important thing for a club like ourselves, to have Premier League experience because if you don't you could end up with a problem," Jol added.
Key defender Brede Hangeland shrugged off an Achilles ache, which forced him off at half-time against United and required a scan, to travel with Norway in midweek, but Bryan Ruiz is still to return to London from international duty with Costa Rica.
"We had 12 players away on international duty and that is awful. Norwich had two or three so we have to consider that problem," Jol added.
Nothing has changed over Hangeland's future, with a contract extension offered to the captain, whose current deal expires at the end of the season.
"It's a status quo situation and hopefully he will change his mind and sign," Jol said.
Jol dismissed suggestions Fulham were interested in Louis Saha before the Frenchman signed for Lazio and is determined to hold on to Swedish midfielder Alexander Kacaniklic despite reported interest from Dynamo Kiev in Ukraine.
"The transfer window over there is still open but we won't let him go anyway," Jol said.
He also intends to retain the services of Sascha Riether, who is on a season-long loan from Cologne.
"We've got an option on him and I think we will take it so he will probably stay here," Jol said.