Hello,

I have a JDM 2007 Lexus IS 350 that has been imported to Canada, when I tested my coolant with a hydrometer it only showed -20C which is very low for where I live (toyota/lexus recommends 55/45 dilution to reach -45C for my region)

After finding this out I did a radiator drain and flush of the system with distilled water until the coolant coming out was more or less fully clear, I then found out that my local dealership does not carry concentrate and only pre-diluted (I know should have checked beforehand) so after 2 expensive rounds of flush and drain I have managed to reach a 35/65 ratio of dilution, with Toyota extra long life coolant (bringing me back to -20 C on the hydrometer).

With a little bit of math toyota coolant being $40 per gal it will cost me another $160~ to reach 50/50 on top of the $120 I have already spent. I went to Canadian tire and found Rocochem’s “OEM” Toyota/Lexus coolant CONCENTRATE which states to be a OAT coolant that is compatible with both OAT and HOAT (what the original Toyota coolant is).

My question is will the 2 coolants be compatible? Because if yes this will be a $30 and 15 minute fix, instead of a $160 and 1.5 hour ordeal. Any input would be much appreciated.


link for the concentrate: https://www.canadiantire.ca/en/pdp/oem-concentrated-anti-freeze-coolant-toyota-lexus-scion-pink-rose-3-78-l-0293072p.0293072.html?rq=lexus+antifreeze#srp

 

Only way to know if coolants are compatible is mix them and wait years to see what happens. Or find someone that has done it. People will tell you it's fine to mix or not, but unless they have specifically done it that's not a valid data point.

Put another way, are you willing to risk a bad chemical reaction to save $200? Your choice.

 

Take it as a loss, and drain the block completely. Then refill with Toyota SLLC predilluted.

Make sure the air is completely gone from the system. With a Lisle funnel it makes bleeding a breeze.

https://www.clublexus.com/how-tos/a/...adiator-362361