Yukon Denali 6.2 towing Travel Trailer

[thompsoj22]

Yes,

I've got a 2015 Denali w/ the 6.2L and tow a 27 ft lance which typically weighs around 6400 lbs loaded. I get up to 13 mpg @ ~ 62 on level ground in the southwest. The Yukon has no trouble pulling the load.

i like your post buuuuut, 13 mpg at 62? and where are you finding level ground in the southwest? Im using humor here so dont get pissed but i tow a 23ft aljo TT at 4500lbs and get 8-9 mpg with an 08 xl1500 6.2 and you have another 2k behind you! either you are having a few beers and the mpg got better or there is somthing significantly changed between the years?

 

[thompsoj22]

I will add that I have a 28ft TT weighs in right around 6,000 lbs. No trouble towing and do it a lot up and down the East Coast. (2012 Denali XL) What I did not like were the high engine and trans temps. I replaced my Back Shocks (Arnott shocks) and Brakes, new rotors, and pads. Flushed the trans and radiator but summertime was still too high and I get that GM says it is normal. With that said she pulled like a champ no issues at all but last May when we had the early heatwave in NC & SC my temps went through the roof and that was enough for me. I added a Tru-Cool 40k and things have been great ever since. Water temp is never above 200 and even on the honest days the Tran Temp barely hits 190 now. One final thing I do not like is the tire availability in our 20in. I wanted a tire that could take a little more cold pressure in the back when towing but did not want the added weight of a true towing tire (d or e) since that will impact comfort when not towing. I got the Goodyear wrangler sr-a p275/55r20, under 500$ delivered to my house from Walmart 45$ for mounting and balancing and lifetime rotation and balance at any Walmart. The load range is 2,400 lbs and max cold tire pressure is 51 and they weigh below 40lbs. I run them at 42 cold in the back when towing which is 10 lbs over the recommended for the truck. I run 38 in the front. This combination to me runs like a top

Short answer

• get your PM out of the way
• make sure your shock system is in top notch conditions
• add bigger and better bumpstops in the back
• get the Tru-Cool
• get some appropriate tires View attachment 244757 View attachment 244759

i have a question in regard to that enormouse cooler in front of the AC condensor. Im considering the same upgrade but feel putting that much heat in front of the condensor will affect ac function? I may try mounting behind the bumper below the lower fairing with a remote fan/cooler unit.

 

[kbuskill]

i like your post buuuuut, 13 mpg at 62? and where are you finding level ground in the southwest? Im using humor here so dont get pissed but i tow a 23ft aljo TT at 4500lbs and get 8-9 mpg with an 08 xl1500 6.2 and you have another 2k behind you! either you are having a few beers and the mpg got better or there is somthing significantly changed between the years?

Something did change... the 2015+ have the direct injection LT engines instead of the LS engines.

 

[avalonandl]

i have a question in regard to that enormouse cooler in front of the AC condensor. Im considering the same upgrade but feel putting that much heat in front of the condensor will affect ac function? I may try mounting behind the bumper below the lower fairing with a remote fan/cooler unit.

No there is plenty of air at 60 mph....

 

[Costal_Cat]

i have a question in regard to that enormouse cooler in front of the AC condensor. Im considering the same upgrade but feel putting that much heat in front of the condensor will affect ac function? I may try mounting behind the bumper below the lower fairing with a remote fan/cooler unit.

I found that everything actually works better AC included. During the noted heatwave, I had to keep the AC off just to keep water temp where I wanted it. Once this was on I can keep AC rolling fine and cold and temps stay fine. As noted by @avalonandl lots of air movement at speed but even in stop and go everything cools quickly. I had the intention of moving it if I did not feel comfortable but I have also seen everyone owner that puts on that TruCool doing the same so I thought I would start there and see what happens. I will note I pretty much run NC to FL and TN to AL from the NC Coast so always hot, humid muggy driving in the summer. I think to start where I have it as it is a 1 hr job at the most see how you like easy to change out. I assume people know but I did take out the stock tranny cooler that was there so install was easier due to that. If you don't have a stick cooler then a few more steps for install.

 

[Larryjb]

I found that everything actually works better AC included. During the noted heatwave, I had to keep the AC off just to keep water temp where I wanted it. Once this was on I can keep AC rolling fine and cold and temps stay fine. As noted by @avalonandl lots of air movement at speed but even in stop and go everything cools quickly. I had the intention of moving it if I did not feel comfortable but I have also seen everyone owner that puts on that TruCool doing the same so I thought I would start there and see what happens. I will note I pretty much run NC to FL and TN to AL from the NC Coast so always hot, humid muggy driving in the summer. I think to start where I have it as it is a 1 hr job at the most see how you like easy to change out. I assume people know but I did take out the stock tranny cooler that was there so install was easier due to that. If you don't have a stick cooler then a few more steps for install.

An important question to ask now is what transmission cooler did you replace? Did you get the cold weather bypass? I believe that is required if the vehicle is to be operated in below freezing temperatures.

My 2002 Tahoe has the Acdelco heavy duty transmission oil cooler which has the dimensions 17x8x3, for a total cooling volume of 408"^3, the Tru-Cool 40k has a total cooling volume of 769.5"^3, approximately twice that of the stock heavy duty cooler. The stock regular transmission oil cooler for the Tahoe has a the dimensions 14"x2.5"x2.5", or a total cooling volume of 87.5"^3.

Disclaimer: I know there is much more to this than these calculated dimensions to cooling. I'm doing this a a "quick and dirty" comparison.

In order from standard to Tru-Cool 40: 87.5"^3, 408"^3, 769"^3.

Heavy duty vs standard: 4-5x more efficient
Tru-Cool vs heavy duty: about 2x more efficient

Given the GVW rating on the Tru-Cool 40k (40000 GVW), I'd say that most shops would say this is way overkill. BUT, given that I have the heavy duty transmission oil cooler, I had a little trouble with a hot engine going up the Coquihalla in BC one summer, pulling a small trailer, albeit heavily loaded. I'm actually quite impressed with your temperature numbers.

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[Costal_Cat]

An important question to ask now is what transmission cooler did you replace? Did you get the cold weather bypass? I believe that is required if the vehicle is to be operated in below freezing temperatures.

My 2002 Tahoe has the Acdelco heavy duty transmission oil cooler which has the dimensions 17x8x3, for a total cooling volume of 408"^3, the Tru-Cool 40k has a total cooling volume of 769.5"^3, approximately twice that of the stock heavy duty cooler. The stock regular transmission oil cooler for the Tahoe has a the dimensions 14"x2.5"x2.5", or a total cooling volume of 87.5"^3.

Disclaimer: I know there is much more to this than these calculated dimensions to cooling. I'm doing this a a "quick and dirty" comparison.

In order from standard to Tru-Cool 40: 87.5"^3, 408"^3, 769"^3.

Heavy duty vs standard: 4-5x more efficient
Tru-Cool vs heavy duty: about 2x more efficient

Given the GVW rating on the Tru-Cool 40k (40000 GVW), I'd say that most shops would say this is way overkill. BUT, given that I have the heavy duty transmission oil cooler, I had a little trouble with a hot engine going up the Coquihalla in BC one summer, pulling a small trailer, albeit heavily loaded. I'm actually quite impressed with your temperature numbers.

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I had

KNP - TRANSMISSION COOLING SYSTEM

Not sure if this code is HD or not. What I can say is the stock one was very small and of a tube and fin type cooler which are not very efficient.
The TruCool is a Stacked plate design that is the most efficient so I'm not sure how to really compare them except to note what I have seen prior and after.
I did not get the cold weather bypass as I live in the southeast on the coast so for the few times it gets colder did not seem worth it. There also seems to be some debate on the need as with factory setup cooling lines go through the radiator and supposedly the valve in there does not open to the cooler until over 190 water temp? I have no idea if that is correct or where I ran across that but I went with none. It might be overkill but at the same time at $130 and my time coupled with the number of folks who have gone this route I figured I would give it a try.

 

[Larryjb]

The KNP should be the heavy duty one, but it is a lot smaller than any of the Tru-Cool ones.

At least, the KNP for 2002 is this one here:
https://www.amazon.com/ACDelco-20880895-Equipment-Automatic-Transmission/dp/B0049417FU

The regular one appears to be ACDELCO 52497562
https://www.amazon.com/ACDelco-52497562-Equipment-Automatic-Transmission/dp/B000C9TO5Q

I will say that for nearly all my towing, the heavy duty cooler did fine. It was just in the extremes like climbing up the Coq. did things struggle.

However, I do like that you were able to keep the AC running. On the Coq our engine temperatures were going a little above 212 at which point I turned the AC off and the heat on. You DO NOT want to have any sort of breakdown on the Coq. If you do a street view, you will see there is no place to pull over at all. At least the California Grapevine has more places to pull over.

Anyway, thanks, I now have some perspective. I'm quite surprised that keeping transmission temperatures down helped out that much with engine temperatures.

 

[Foggy]

Just to add to this: If you don't want to take apart the front bumper/grill to
add an aux trans cooler you can replace the stock trans pan with one like
a B&M unit that has cooling fins on it and also holds about 2-3 qts more fluid.
I've used these types of pans on several of my vehicles and I can say that they
do work. Also you get the advantage of a drain plug and a pre-tapped bung for
adding a trans temp gauge if you like. Plus they are heavy and solid cast alum
so IMO they help "square" up the case and pan for some more rigidity

 

[gooffeyguy]

The KNP should be the heavy duty one, but it is a lot smaller than any of the Tru-Cool ones.

At least, the KNP for 2002 is this one here:
https://www.amazon.com/ACDelco-20880895-Equipment-Automatic-Transmission/dp/B0049417FU

The regular one appears to be ACDELCO 52497562
https://www.amazon.com/ACDelco-52497562-Equipment-Automatic-Transmission/dp/B000C9TO5Q

I will say that for nearly all my towing, the heavy duty cooler did fine. It was just in the extremes like climbing up the Coq. did things struggle.

However, I do like that you were able to keep the AC running. On the Coq our engine temperatures were going a little above 212 at which point I turned the AC off and the heat on. You DO NOT want to have any sort of breakdown on the Coq. If you do a street view, you will see there is no place to pull over at all. At least the California Grapevine has more places to pull over.

Anyway, thanks, I now have some perspective. I'm quite surprised that keeping transmission temperatures down helped out that much with engine temperatures.

That KNP one you linked to first is the same one that came on my 2012 Denali

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18