how cold is too cold for Dexron VI

[Timeking]

I get the max temp discussion, too hot is bad ... but when its cold out, how long should I idle to get the temperature above ... what temp? Is 65F ok to start driving? 45? I have a post-radiator tranny cooler installed, and am planning to tow a 5000 lb travel trailer to Maine and upstate NY, leaving in September and returning in late November, using a 5.3L Trailblazer. There is no aftermarket bypass installed, and I guess that is the question here. I've towed 12,000 miles thru the rockies with no problem, but other than a late season blizzard in Yellowstone, never been in any cold weather. I live in Florida.

 

[Tempest]

Idling to warm up a car should not be done as it takes longer for the car to warm up, which causes more wear and fuel dilution.

Dex VI should be good down to ~-40F.

 

[cp3]

Idling will also not bring the trans temp up very quickly anyway. Much better to drive it gently and let everything warm up together IMO.

 

[Timeking]

So basically if it gets down into the 20's or teens at night, I need to just take it easy (which is what I have been doing when it was cold out west until the tranny temp read >70). That said, if I ever ride out the winter in Rapid City, then it would be advisable to install a bypass; otherwise, not needed.

 

[jrustles]

How cold is too cold for DexVI?
When it's wayy too cold for previous non-synthetic ATF specifications.