For the 2018 Chevrolet Volt, the low-beam headlight is listed as LED, while the high-beam headlight uses a 9005 bulb. These are separate fitments, so verify which lighting function you are servicing before ordering. The supplied data does not list a fog-light bulb for this model year.
Additional exterior lighting includes a 7444NA bulb for the front turn signal and parking light, a 7440A bulb for the rear turn signal, and a 7440 bulb for the reverse light. The brake light uses a 7443R bulb. The center stop light, daytime running lights, rear side markers, and tail lights are listed as LED.
For smaller utility lights, the license-plate lighting may use either 2825 or 98, while the trunk light may use 194 or 7441. The vanity light is listed as 7065. Because multiple bulb options are supplied for the license-plate and trunk locations, compare the existing bulb and socket before purchasing.