I believe the OEM manual states in the footnotes, after the first coolant change 100K+ miles - your suppose to move to 50K mile coolant changes??? So do you really need SLL coolants at 50K mile intervals? Is that a moot point??? Just playing devils advocate......
The drop in interval it to compensate for not getting all the old coolant out. What is the alternative?
I am only familiar with those as specifications for VW-Audi coolants (there's G12, G12+, G12++, and G13). Posted via the PriusChat mobile app.
This is indeed true, it seem G13 has glycol partly derived from glycerin (via bio diesel) instead of petroleum. EU likes the environment, but this seem a tad comical since many sources state only 10% of glycol content is derived from that bio source) I am currently using G13 at my own risk in my 2005 Wild Guinea Pig Prius. Promotional info here: What you need to know about G13 antifreeze and coolant
