Merhi bemoans weight difference to F1 team-mate Stevens

Taller than Stevens by a few inches, Merhi has been out-qualified by the Briton every time both drivers have attempted to qualify this season.

Stevens also finished ahead of the Spaniard three times in a row before Merhi finally saw the chequered flag first around the streets of Monte Carlo.

Merhi told AUTOSPORT: "The weight is not helping so much. It affects the weight distribution on the car.

"I am 10 kilograms heavier, or something like that, so my weight distribution is much more forward compared to his car and is not helping so much."

Although Merhi has slimmed down since the opening grand prix of the season in Australia - one in which Manor failed to compete due to technical issues - he does not feel he can do any more.

"Since Melbourne I have lost four or five kilos," he said.

"In Melbourne I was 14 or 15 kilos more compared to him and now I am maybe 10 or 11, something like that.

"I don't know how much more I can afford to lose. I thought five kilograms was the limit.

"To lose another five is hard. The first two will be easy, the other three very hard, so maybe I'm just going to have to eat salad!"

The 24-year-old, whose seat with the team appears assured for the time being given he was initially only brought in for the opening few races, has also had issues with the top speed of his car.

Although Monaco masked such problems, the long straights of the Circuit Gilles Villeneuve - the scene for this weekend's Canadian Grand Prix - could highlight them again.

"We did have some issues in Barcelona with top speed," added Merhi.

"We do not have a good top speed compared to Will, so we have been working on that to ensure it is the same for both cars."

As to whether the Manor drivers receive the same equipment, Merhi said: "More or less.

"We try to get the same equipment. Normally it should be everything."