Does the color matter?
Antifreeze color does not matter. The chemicals that make up the antifreeze do. Relying on the color of the coolant is not a reliable way to tell what’s in an antifreeze. You should consult the maintenance chart in your vehicle’s owner’s manual to find which antifreeze the manufacturer recommends. Different car makers have their own antifreeze formulas that are designed to work best with the metals they used to build the engine and cooling systems. Following the manufacturer’s recommendations will ensure that you are getting the one that works best for your vehicle.
Will using the wrong antifreeze damage my vehicle?
Probably not, but not maintaining the right coolant-to-water ratio could. The coolant mixture in cars should always be kept around fifty percent distilled water and fifty percent antifreeze (50-50). Having too much antifreeze in the mixture causes unnecessary wear on your water pump. Antifreeze is thicker than water, and your water pump has to work harder to pump a thicker coolant mixture through your vehicle’s cooling system. Having too much water can prevent the antifreeze from fighting corrosion and buildup in the cooling and engine system.
Using undistilled water to dilute your coolant can also harm your vehicle. Since all tap water and well water contains various minerals that react with metal, using this water can cause mineral buildup in your cooling system, clog your water pump, and damage your heater core. This may cause the heater in your car to fail.
Many antifreeze makers offer a pre-mixed 50-50 coolant, which is always fifty percent antifreeze and fifty percent distilled water.
Can I mix different antifreezes?
Most experts say that you should not mix propylene glycol (PG) antifreezes with ethylene glycol (EG) ones. The two can react with each other and create deposits and residue in your cooling system. This can be avoided by following your vehicle’s manufacturer recommendations. Mixing any brand or color of PG antifreeze with another brand or color of PG will not cause any problems in your vehicle as long as you keep your coolant mixture around 50-50. The same goes for different brands and colors of EG antifreeze. You can mix a PG with a PG, or an EG with and EG, but not a PG with and EG. If you own a GM vehicle that uses Dex-Cool antifreeze, use only antifreezes that meet the Dex-Cool specifications.
If you suspect that you may have EG and PG coolant mixed in your vehicle, have your radiator flushed and filled as soon as possible. You should have your radiator flushed every 35,000 miles as part of your regular maintenance schedule.