Monthly coolant change?? First time I heard this. Wait a minute, you are kidding around right??Long life.
If you don't trust the manufacturers recommendation, why do you trust the "2 year" policy.
You have 2 real choices.
Either get the long life stuff or change your coolant monthly.
I did not know that-! I'm good to try it but I don't get the once a month change or was it even two monthsThe corrosion inhibitors in the antifreeze deplete. The long life juice just takes longer. I'd use either motorcycle specific antifreeze, or Zerex Asian Engine formula, or any Japanese auto maker's antifreeze.
Here's an easy check of the condition of the corrosion inhibitors...with cool coolant, remove the radiator cap and put one probe of a voltmeter into the coolant without touching metal. Put the other probe on the battery negative post. If you read 0.1 to 0.3 volts DC, you're good. If you read higher voltage you're seeing your engine as a galvanic corrosion cell. You're overdue to flush and renew the coolant.
Why not trust the new chemistry? Suzuki says their blue juice is good for 4 years. GM screwed up with a chemical in DexCool that softened certain gasket material (that another department of GM specified), and cheap shoddy radiator caps that let air in. Other than that, other versions of long life coolant have worked well.I change the coolant every 2 years in all my vehicles. I don't believe in long life coolants and such.
Nothing lasts forever.