Fernando Alonso says McLaren currently has the third-best chassis behind Mercedes and Red Bull on the F1 grid and is pleased to be ahead of Ferrari.

The two-time F1 world champion left Ferrari for McLaren at the end of the 2014 season in the belief the Italian manufacturer wasn't in the position to battle for a world title while he saw extra motivation attempting to turn the new McLaren-Honda partnership into a winning combination.

Despite the Woking-based team's struggles, largely down to an unreliable and under-performing Honda power unit, Alonso has been impressed with the work completed on the chassis and aerodynamic elements of his MP4-31 and places McLaren third in terms of performance in those categories.

"We are behind Mercedes and Red Bull but they are very strong so we need to show in the next few races that we can improve our efficiency and mechanically grip," Alonso said. "Maybe it is a surprise we are in front of many of our competitors but it is not for us. Good to be in front of Williams, Force India, Ferrari in terms of chassis."

Looking at McLaren's performance in Spain specifically, Alonso says the gains made on the chassis side helped him break into Q3 of qualifying for the first time since returning to McLaren and felt a points finish was possible until he suffered a frustrating engine problem, forcing him to retire from his home race.

"You need the aerodynamics and efficient car, you need the power but less than Russia, braking performance in all types of corners," he said. "It is a good reference and we are close to the top ten so that is what we deserve now but we need to improve with a long way to go. Not disappointed and in the last sector we are third-fastest car only behind Mercedes and Red Bull which is okay."