Chevrolet Bolt EV Back Up Light Bulb Size

Additional Notes

• The 921 is the sole backup light bulb size listed across all model years in the specifications, spanning 2017-2023 for the Chevrolet Bolt EV.
• The 921 bulb follows the ANSI standard, which is the recognized specification body for lamp and lighting products in the United States and Canada.
• The T15 designation refers to the bulb's tubular glass envelope, with the numeric portion indicating the width in eighths of an inch, making the T15 a relatively compact form factor within the wedge bulb family.
• The wedge base design means the bulb is held in place by the tension of its base contacts rather than a bayonet or screw mechanism, a common construction in automotive reverse light applications.
• The 921 operates at 12 volts and 16 watts, consistent with standard 12V automotive electrical systems found in passenger vehicles.
• The 921 and 194 are both T-series wedge bulbs but are not interchangeable; the 194 operates at a lower wattage of 3.78W, making it unsuitable as a direct replacement for the 16W 921 in backup light positions.