Goldman Sachs analyst David Tamberrino downgraded General Motors (GM) to Sell from Neutral saying his price target of $32 offers 28% potential downside. The analyst continues to believe the North America auto cycle has peaked and he remains cautious on the sector. He sees “outsized downside” to shares of GM and expects a negative earnings inflection in 2018. Ford’s (F) recently refreshed F-Series leaves GM vulnerable to share loss in 2018, Tamberrino tells investors in a research note. The analyst views Ford shares as more fairly valued. He keeps a Neutral rating on the name while upping his target for the shares to $13 from $10.