antifreeze good or bad
I have a 200 tundra that has 10,469 miles with factory antifreeze in it do i
need to replace. Look's & smells & test fine?
Yes as antifreeze looses a lot of it protective and anti corrosion properties over time and if it has never been done you may have already started internal corrosion even though you may not see it. As you have waited this long I would have it back flushed with a machine at a shop and then refilled with Toyota coolant to the proper specs.
Replace it as the additive package will be used up.
I would replace it. Don't be cheap! This is $20 or so, not a biggie.