The oil drain plug on a 2015 Honda Civic typically requires a 14 mm socket and uses an M14 x 1.5 thread on the oil pan.
This sizing covers the common 2015 Civics with the standard inline-4 engines found in most trims. Variations can occur by engine variant or production batch, so it’s wise to verify with the official manual or a Honda service resource for your exact vehicle.
Standard size you can expect
For routine oil changes, you’ll generally need a 14 mm socket to loosen and tighten the drain plug. The thread standard is metric M14 x 1.5, meaning the plug threads into the oil pan with that pitch.
Engine variants and potential differences
Most 2015 Civics share this drain plug size, but some trims or production runs could differ slightly. If you’re unsure, confirm the exact specification by checking the owner's manual or the Honda service literature for your engine code and VIN.
How to confirm for your vehicle
To be certain, consult the official owner's manual or a dealer/repair manual for your specific engine variant. If you have access to the existing drain plug, you can verify by attempting to fit a 14 mm hex socket; a proper fit indicates the standard size. Avoid forcing other socket sizes on a bolt that may require a precise fit.
Summary
In short, the typical oil drain plug size for a 2015 Honda Civic is a 14 mm hex head with an M14 x 1.5 thread. Always verify against your specific engine code and vehicle documentation to account for any variations.