When upgrading the stock halogen / incandescent lamps to led lighting bulbs, the bulb size guide will be much helpful, below are the bulb size guide for 2005~2010 Chevrolet Cobalt; yet it is for reference only, it is suggested to check the owner manual to confirm the bulb size guide is correct before purchasing.
- High beam headlight and Low beam headlight: 9007
- Fog light: H11 / H11LL
- Front turn signal light ( blinker light)/ Parking light: 3457NAK / 3457A
- Rear turn signal light / Brake light / Tail light: 3157 / 3157KX / 3157-SCK
- Back-up reverse light: 921 / 921K
- 3rd Brake light / Center high mount stop light: 921
- License plate light / Tag light: 194 / W5W
- Interior Dome light: 561 / 562
- Interior Map light: 2825 / 194 / 192
- Trunk / Cargo area light : 168
- Auto trans indicator Light: 37
- Courtesy light: 212-2
- Turn signal indicator light: 37
- Front and rear side marker light: 192 / 194
