Ah, I see. This is an example of their claims not actually holding up in the real world. Apparently marketing bs.

What's interesting is my trans temp seemed consistent on my 1000 mile drive from Denver to Chicago. It stayed between 167 and 169.3F for the entire ride. I suppose that does not compare once you add a 3000 to 5000 lb load and throw in some hills along the way.

I'm curious what type of oil coolers and sizes Toyota equipped these trucks with from the factory and what type of bypass, if any, they used.

I don't think it's necessarily marketing BS. The stated purpose for their bypass is to allow faster warmup, not to regulate the temp to a specific level. I'm not sure how it's calibrated to do that but it has to be different than the external valve, which is simply set to open when the fluid temp reaches 180° F. It's actually pretty cool (no pun intended) when I have OBD Fusion running to see the fluid temp get up to the point where the valve opens. You can watch the temp start falling back to 180 like a countdown clock. I'm going to screen-record that when I have a chance and post it.

Yeah, I suppose my marketing comment was a bit harsh. In summary for my specific trip, it sounds like I could run without a cooler, with a cooler or a cooler and external thermostat. If I did use the 4Runner I would definitely go with either of the last two options.

Realistically, I just need to decide which way to go. Either a rental truck, pod or using my truck. In order to use my truck, I have to drive it down to FL. Not sure how fuel efficient or comfortable driving my truck back in 4th gear at speeds of 60 or 65 will actually be. Fuel economy of the 4runner with a trailer maybe comparable to a Budget cargo van or 12' moving truck. Cost wise, either of the rental truck options will be around $1100 - $1200 more.

I still get 15 mpg easy in 4th gear towing my 13 foot camper all around with my V6. On nice roads with no wind, I even keep it in 5th gear.

So what is the deal with inlet ports sizing?

I assume it is for ease of installation with the existing cooler lines so it is best to purchase a external cooler and additional lines that have the same size as OEM.

Is that correct? If so, then the stock lines are 3/8"?

The Hayden universal one I got from AutoZone came with hoses and they fit tight on the factory V6 fittings. Just barely enough hose, though. Only one way to mount it with what they provide

The aftermarket coolers come with 11/32” hose not 3/8”. Of course the truck is metric. 3/8” is bigger and can handle more volume especially when you are extending the fluid path by 3’-4’. I prefer Gates hose. Check o’reilys and ebay for bulk purchase prices.

"Of course the truck is metric." Light bulb moment...

Thanks for the info as I have yet to do this still.

We tow our 22 foot Pathfinder boat (about 2600 lbs) to the Keys with our '04 4runner. It has 198K on it. The tow is about 5 to 6 hours mostly flat but the 4Runner does great. We tow around 63 mph.

Thanks for all the responses so far.

We ended up going with Uhaul Boxes for the move back. I’m actually in the process of packing them up now.

This way we will be driving back together in one car as opposed to me driving the 4Runner and trailer by myself.

I may choose to add the cooler later as I suppose it would help with some of the mountain driving I do on road trips. At the very least I will monitor the temps next time around just to see how hot the trans does get even when driving in lower gears like 4th or 3rd on steeper inclines and declines.