How McLaren's cautious approach is yielding big rewards in F1 title fight

McLaren team principal Andrea Stella explained in Saudi Arabia that the new diffuser the team brought and submitted through the official FIA declaration process was, in fact, just a test item for the two practice sessions on Friday in Jeddah. 

The MCL39's diffuser was modified at the trailing edge to have a greater upward inclination, thus increasing the expansion area of the exit flow. 

It was not a big visible modification, but it was ideal to test in Jeddah owing to the smooth track surface without any bumps. In practice, it was as if the Saudi track was used as an open-air wind tunnel, with the full-sized car actually in motion to evaluate the effectiveness of the upgrade.

Valuable data was collected to find the range where the modified diffuser would have the greatest effect, with the engineers looking to correlate and verify the upgrades worked in the desired speed ranges and ride height configurations. 

The car does not require radical developments, but the team is already testing various components that will be introduced shortly and over the coming races.

The team hopes that increasing performance will not induce critical issues in balance and setups. 

A very precise, methodological approach is being followed, which McLaren is trying to prolong through the season without taking unnecessary risks with upgrades.