Antifreeze PEAK or OEM Toyota

The Peak coolant that is the correct color for your year, i.e. pink for the MkIV, is fine. I have been using it for several years with no problems.

I ran the euro Peak without issue for about a year but I was bleeding coolant and in desperate need of the cooling system overhaul.

My car is currently filled with the Peak Euro Blue stuff, works fine, identical to the OE BMW formula anyway

I personally use Peak brand coolant, and I've never had an issue for 100K+ miles.

The green does "work" but it wont help the health of the engine long term as there are chemicals in the Toyota red which help protect the engine, fittings, rad etc. Buy the right stuff from Toyota and it'll last ages, the wrong stuff will screw things up long term.

Even though most will say to stick with G12/G13, I think that is where that "sand" comes from. I decided last year to completely drain the system - including engine block - and converted to Peak antifreeze. I have not had any problems since.

I did this a few weeks ago on my '13 Sequoia, but I did not flush it. Just drained the rad and the valves on the block. Replaced with Toyota red and distilled water at 50/50. The fluid I drained was as clear as the fluid I replaced, so I felt flushing was not necessary.

Toyota brand coolant is top notch, supposedly can last for the entire life of a car and never needs to be replaced