Since its early-season spike in form, Mercedes has slid from competitiveness.
Outwardly, the car remains much as it appeared at the start of the year, but following a successful three-day test at Magny-Cours, the team arrived in Singapore with some new upgrades ready to race, most notably the revised exhaust system and sidepod set-up.
The W03's problems this year have stemmed largely from excessive rear tyre wear. Rather than rush to put different solutions onto the car, the team has worked at the problem methodically, concentrating initially on set-up, then introducing a major upgrade around Monaco.
This mechanical upgrade was focused on the rear end, with a carbon gearbox case and suspension changes.
So far, Mercedes, like Lotus, has been one of the few teams not to have followed the downwashed exhaust method of blowing the diffuser. Now, it has a revised package that reaps the benefit of the exhaust plumes being aimed at the diffuser.
Previously, its periscope-style set-up aimed the exhaust energy mainly at the lower rear wing and not the diffuser.
With its new installation, the exhaust now blows through a bulged side extension to the sidepod, in the same style as McLaren has pioneered since the start of the season.
The last 100mm of exhaust tailpipe exits deep inside the side extension, pointed upwards and outwards. But the slope of the sidepod top and the deep slot forming the side extension create a downwash of airflow over the exhaust's exit.
It's this airflow that deflects the exhaust plume back down towards the gap between the diffuser and rear tyre.
This flow of fast-moving exhaust gas both speeds up the flow through the diffuser and seals the side off from leakage. The latter effect also allows the team to run higher at the rear, the added rake in the car's angle to the track creating even more downforce.
This additional downforce will help Mercedes preserve its rear tyres for longer, allowing longer stints and fewer stops in the race, like its rivals. It's likely to add up to a big step in performance for the team.