People debate about whether to use coolant at all aside from distilled water in your engine. Most experts agree that using a minimum of 20 percent coolant in your engine is necessary as this helps lubricate the moving parts of your water pump. Most manufacturers utilize a 50:50 coolant and distilled water mix from the factory, however. So stay in between the range of 20 and 50 percent coolant, with the rest being the purest, cleanest distilled water inside your engine and radiator.
And let me reiterate to only use coolants from a known or trusted brand such as Motul’s Inugel, Toyota’s factory fill Red Coolant concentrate (popular with many amateur racers in the US even when used in different brands of cars), and Japanese performance brands like Billion’s Super Thermo line of coolants, ARC’s own line of coolants and locally, Caltex/Texaco’s Orange Coolant Concentrate.