"We tried to improve aerodynamic efficiency and reduce weight, but we're not talking about five kilograms," boss Wolff told Spain's El Mundo Deportivo.
"In formula one it is difficult to make big steps like that -- they are all small. We are working more with grams than kilograms," he added.
Indeed, a tired-looking Hamilton admitted after the race that he is even going without an in-car drink bottle to save weight, despite the increased physical difficulty of racing with the 2017 cars.
"I don't carry drinks in my car to save weight," he revealed. "I was a little bit tired after that one."
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