The Frenchman told Motorsport.com: “This car showed great speed in some conditions last year, but if you check the overall result from last year and my first impression from the car is that it needs to be able to be fast in more conditions.
“It’s definitely fast on some conditions, but not on all and that’s what we need to improve.”
Asked how long he needed to turn the C3 into a potential winner everywhere, Ogier said: “It’s a difficult question to answer, but so far the first test went OK.
“But, for sure, there is things we need to change better to my taste. It’s difficult to estimate how long it’s going to take to do that.
“We have started to work for the first two days [on asphalt for Monte Carlo]. This gives me a good learning of the car in different conditions and what I need to do to adapt it to the conditions.”
As well as consistent speed, Ogier says the key to a seventh straight title in 2019 lies in consistently scoring points.
He said: “[I aim] for the same place like last year… that would be OK! I always aim high, it’s no question, we will see.
“I’m pretty relaxed and I don’t want to put any more pressure on my shoulders. If this [result] is not coming, we will work even harder.
“For the season, the strategy is to be consistent. Everybody should have this target if they want to play a championship. This was always my target; at Volkswagen it was always consistent – consistently first!
“Now it was a bit harder in the last years, but the strategy hasn’t changed. Last year we had a good speed at the beginning of the season, a bit less in the middle and then in the end of the season we did what we had to do.
“So far I didn’t really make a strategy for 2019, just to start as well as possible.”