Mercedes' 'Phase 2' engine made its debut in Friday practice for the Canadian Grand Prix, although its drivers played down the performance step it would bring relative to chief rival Ferrari.
Although it has dominated the V6 turbo-hybrid engine era of F1 since 2014, Mercedes' enduring success is a legacy of significant improvements with its chassis as well as the quality of the power unit.
Asked by Motorsport.com about the step he expected from the upgraded engine, Hamilton said: "The guys back at Brixworth have been working incredibly hard.
At the end of last year, team principal Wolff said Mercedes had suffered a small setback with its development of the 2019 engine.
Asked in Canada by Motorsport.com about the difficulties Hamilton had referenced, Wolff said: "We had times at Mercedes where the engine was described as the determining factor in the team's success and then it has somehow transitioned to the chassis side.