What was the original association between IWC, Ingenieur, and Formula One?

There was no direct relation between watch companies and Formula one. IWC, as
much other watch companies have a marketing relationship with a F1 team.

As a logical continuation of the partnership with Mercedes-AMG, IWC became the
"Official Engineering Partner" of the Mercedes-AMG PETRONAS Formula One™ Team
in 2013. The partnership is founded on the mutual passion for mechanical
engineering and a shared commitment to excellence.