Rubuta ci gaba don wannan sakin layi - Haas ya riƙe Grosjean don kakar 2018 inda ya sake yin haɗin gwiwa tare da Magnussen. A Grand Prix na Azerbaijan, Grosjean ya yi hadari a bayan motar aminci yayin da yake gudu a matsayi na 6. Injiniyan sa yayi kuskuren zargi dalilin hadarin akan direban Sauber Marcus Ericsson, yana cewa, "Ina ganin Ericsson ya buge mu". A gasar Grand Prix ta Spain
, Grosjean ne ya haddasa hadari a zagayen farko. Yayin da yake yin hanyarsa ta hanyar juyawa 3, ya rasa ikon Haas dinsa bayan ya gudu ta cikin iska mai datti. Wannan ya sa ya juya a fadin hanya a cikin hanyar motocin da ke bayansa, yana haifar da hayaki mai yawa a cikin tsari. Daga nan sai Hülkenberg da Gasly suka buge shi, suka kawar da duka ukun daga tseren. A cikin Grand Prix na Austrian, Grosjean ya gama na 4, mafi kyawun aikinsa a Haas da kuma maki na farko a shekarar 2018. An cire Grosjean daga gasar Grand Prix ta Italiya bayan an gano cewa bene na motarsa ba bisa doka ba ne, yana kawar da matsayi na shida; kodayake ƙungiyar ta daukaka kara game da wannan, an tabbatar da shawarar. Grosjean ya gama kakar wasa ta 14 tare da maki 37.