If you weren’t already focused on your mobile site’s performance, Google is giving you a reason. In July of 2018, Google will use a new ranking signal focused purely on mobile site speed: the “Speed Update.”
Google will dampen rankings for slower mobile sites to help mobile searchers find sites that deliver what Google considers to be a better mobile experience.
Desktop site speed has been a Google ranking factor for almost eight years — Google’s obsession with speed isn’t anything new. What is new is that Google will now include mobile sites in the site speed ranking equation.
Source: JIll Kocher Brown, Practical Exommerce