Is it really a big deal if I use tap water in my coolant instead of distilled water? What is the difference anyway?

Video Transcription:
All right, is there a winter and a summer coolant? Actually, no. The coolant in the car, and it is called coolant now not anti-freeze, is year round. You use the same thing all year long. If you should have a leak, well in this time of the year, you could add a little bit of water to top it off in an emergency, as long as you get the leak repaired and get the proper concentration- 50% coolant, 50% distilled water- back in the car as soon as you possibly can.

The question comes up: Do I use regular tap water when mixing my coolant and water together? No, you should use distilled water or better yet, de-ionized water. The reason for this is that tap water has minerals that can deform deposits inside the radiator and the cooling system passages of your engine. And over a long period of time they can lead to over-heating.

About

Pat Goss is the master technician on the television program MotorWeek, where he hosts a segment called Goss' Garage. Known as "America's Most Trusted Mechanic," Pat is the President/Owner of Pat Goss Car World, Inc. in Seabrook, MD. It is considered one of the best outfitted shops in the country. He helps consumers understand car problems and teaches them how to speak the same language as their technician. Since 2008 Pat has been a spokesperson for CARCHEX, a Hunt Valley, Maryland-based company and the premier provider of Extended Auto Warranties and Mobile Vehicle Inspections.