What coolant should I use?

[Blackcar]

Just curious... What do dealers use for coolant?

In all the garages I have been in, I haven't seen anything labeled as a distilled water supply.
Just a hose hooked to a spigot on the wall, which gets used for everything.

Do dealers use pre-mixed 50/50 from bulk supply tanks?
I would be surprised, if they were mixing on the fly for each vehicle.

I have never spotted anything in any service bay, labeled distilled water. No hoses, tanks or jugs. I haven't seen any delivery tankers trucking in new supplies of distilled water either.

Are they just using reverse osmosis filters in the shop to filter out impurities in the water?

Mom and pop shops are probably not likely to even have a filter. Probably just a garden hose to a tap.

Anybody have any "behind the scenes" insights?

There object is to repair at least cost for more profit, and if it causes different problems elsewhere another repair down road. this happens in alot of repairs.

 

[2006Tahoe2WD]

Also I use the premixed Dexcool. I figure they use the water purity that is required.

 

[JamesLond]

Here's a video I found that echo's SnowDrifter's fill instructions.

I did add the coolant and let it idle for quite some time. The temp went up to around 197F. That sound right?