50-50 is what all brands recommend, the "lower mixture" would refer to those who think 80-20 or such gives more freeze protection, straight antifreeze doesn't cool as well .... if you're having heating problems, you need to clean/check over the system, it's not the coolant mix

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics