Jenson Button says McLaren has to improve all areas of its car to compete at the front, not just its Honda power unit.
Despite an obvious improvement in performance on last year, McLaren-Honda has only scored one point in the opening three races of 2016. Although Honda's power unit is still down on power compared to Mercedes and Ferrari, Button says it is unfair to focus on just the engine.
"I'm sure it's not the best car out there either," he said. "There's areas we need to improve on the car, as well as the power unit, so you can't just point a finger at one area that needs to be improved. Bahrain, you wouldn't have thought it would have been a circuit that suited us, but I think the pace was pretty good and I had a chance of getting a good result."
Button says Mercedes and Ferrari remain the references for both power unit and chassis design in Formula One.
"I mean in terms of trying to find the power that Mercedes and Ferrari have I think that is always going to be difficult when you are behind because they are always improving, so it's difficult to make a big step forward of ICE power. Apart from that, no I don't think there is any real sticking point, we're improving as we sort of expect. The car is pretty good, I don't think it's as good as a Ferrari or a Mercedes but there aren't many cars I don't think apart from those two that are stronger than us."