How often should you change your transmission fluid in a Honda Civic?

If your Transmission Fluid is in bad condition and you choose to immediately drain and fill the transmission with fresh fluid until all old fluid has been removed, then this can cause problems. It is highly recommended to just perform one drain + fill, and then wait at least a few thousand miles before performing another drain + fill. Do once more after a few thousand miles further and by now most of the old fluid is diluted down enough. You see, when you drain + fill Civic transmissions, you are only getting out approximately 1/3 of the total fluid, Not all will drain out from the drain bolt hole.

After doing the above steps, perform a drain + fill every 30,000 miles for best maintenance.

Never changing your transmission fluid can cause disastrous consequences.