Honda’s power deficit ‘impressive’ - Fernando Alonso

With Alonso's team-mate Stoffel Vandoorne unable to start the race due to engine problems, the Spaniard spent his evening battling for positions outside the top 10, and complaining on the radio about how slow he was compared to those he was racing against.

"All race long the [lack of] speed we had on the straights was impressive," said Alonso, who said at one point in the cockpit that he'd "never raced with less power in my life".

"We were running close to the points but we were incapable of getting anything else out of this grand prix.

"There were times on the straight when I looked in the mirror, I saw they were 300 or 400 metres behind so I started changing things on the wheel or listening to instructions, and then under braking they were right with me and I thought it was not possible.

"But that's what we have at the moment - so a tough race in that sense.

"I don't know how much power we had in the race compared to normal conditions, but regardless of that, we are too slow, in both qualifying and the race."

Alonso retired late on with "some problem in the engine", and he has accepted that Honda is not going to be able to turn its fortunes around quickly this season.

"We have to be a bit patient, wait for the improvements in the next races, but the next three to four races will be complicated," he added.

"In Russia the engine also counts a lot, so hopefully Barcelona [round five] is the first race without so many straights and we can be a bit more competitive.

"We never had the pace we did in China or Australia, we were a little bit slower today, so we need to keep improving.

"We know what is the weakness of the package."

Alonso's attention will turn to preparations for his Indianapolis 500 debut from Monday, when he will be in contact with his Andretti Autosport team to get ready for the IndyCar event at the end of May.

"We are going to focus on the 500 for a bit," he said.

"From tomorrow we are going to study a bit and be in touch with the team to see the telemetry for the first time to see how things are over there.

"It will be good to refresh the mind."