6L80E thermostat delete sure-cool cooler kit

SierraHD17 · March 13, 2020

Nobody needs the thermostat... its something GM cooked up for fuel economy gains... Even the HD trucks with 6L90es through 2019 for sure don't have one and neither does any automatic (including the exact same 6L80e) prior to 2014. Good way to cook the oil when you tow.

truckguy82 · March 14, 2020

15 hours ago, SierraHD17 said:

Nobody needs the thermostat... its something GM cooked up for fuel economy gains... Even the HD trucks with 6L90es through 2019 for sure don't have one and neither does any automatic (including the exact same 6L80e) prior to 2014. Good way to cook the oil when you tow.

Yeah but if if’s 20 degrees out and you’re not towing, your trans temp will be like 100 degrees. I’m sure there is a significant bump in fuel economy which I don’t mind at all.

Personally I’d rather have the trans thermostat at like 160. But i’m just going to assume the engineers know what they are talking about by setting it at 190

Mozzer · March 14, 2020

. But i’m just going to assume the engineers know what they are talking about by setting it at 190

This forum would be a very quiet place if that were the case [emoji1787]

The product that started the thread should achieve the lower opening temperature I believe.

2014, 5.3, 4x4, work truck

Grumpy Bear · March 14, 2020

2 hours ago, truckguy82 said:

Yeah but if if’s 20 degrees out and you’re not towing, your trans temp will be like 100 degrees. I’m sure there is a significant bump in fuel economy which I don’t mind at all.

Personally I’d rather have the trans thermostat at like 160. But i’m just going to assume the engineers know what they are talking about by setting it at 190

This is with water thermostats of 180 F and 170 F. 20F air temperature = @ 115 F ATF temperature between 50 and 55 mph. It's warmer if driven slower or faster than this. Heat up time is about twenty minutes of highway driving vs over an hour with the factory thermostat. If your running the factory water thermostat and with only the cooler in the radiator it will be about 25 to 30 degrees warmer. Remember a radiator cooled transmission rides on the water temperature as a fluid HEATER until the transmissions fluid temperature exceeds the tanks temperature then its a cooler. This graph is data I collected over two years of experiments with Pepper. She's a V6. Your V8's have the cooler in the hot tank v cold tank for the V6 applications. Yours will be warmer. IF you have the max tow package you have a second cooler in the upper part of the AC condenser. I have no idea how that would play out. You will have to experiment for yourself on that one. Fact is I don't know if Max Tow even has a thermostat.

Coolers for AT's have been in the cold tank for almost every one made for the last 75 years and NONE had a thermostat.

SierraHD17 · March 14, 2020

4 hours ago, truckguy82 said:

Yeah but if if’s 20 degrees out and you’re not towing, your trans temp will be like 100 degrees. I’m sure there is a significant bump in fuel economy which I don’t mind at all.

Personally I’d rather have the trans thermostat at like 160. But i’m just going to assume the engineers know what they are talking about by setting it at 190

About as significant as running 5w30 oil versus 0w20 lol... negligible. As mentioned your tube pass in the radiator tank acts as a heater anyway with any fluid temp below the cooling system temp.

Edited March 14, 2020 by SierraHD17

truckguy82 · March 14, 2020

54 minutes ago, SierraHD17 said:

About as significant as running 5w30 oil versus 0w20 lol... negligible. As mentioned your tube pass in the radiator tank acts as a heater anyway with any fluid temp below the cooling system temp.

Yeah and any change in oil viscosity likely has a considerable effect on efficiency inside a transmission.

There’s a few reasons we get 25mpg+ highway, that’s one of them IMO.

Mike GMC · March 14, 2020

I've been doing some searching, but I can't seem to find much. Does the 8L90E have a similar thermostat? Can it be bypassed or removed as well?

Grumpy Bear · March 15, 2020

6 hours ago, truckguy82 said:

Yeah and any change in oil viscosity likely has a considerable effect on efficiency inside a transmission.

There’s a few reasons we get 25mpg+ highway, that’s one of them IMO.

I get about 25 mpg in the winter. 30 in the summer. My trans temperatures are as shown in the graph.

truckguy82 · March 15, 2020

15 hours ago, Grumpy Bear said:

I get about 25 mpg in the winter. 30 in the summer. My trans temperatures are as shown in the graph.

Well since you are the slowest driving human alive, I’d say your output data is skewed.

Grumpy Bear · March 15, 2020

7 hours ago, truckguy82 said:

Well since you are the slowest driving human alive, I’d say your output data is skewed.

Hey there Mister, I passed someone yesterday.

:crackup:

As you can see I tested in 5 mph increments between 30 mph and 75 mph.

Then I chose to gather data were is was most efficient.

So the data is not skewed. It represents the coldest possible temperatures.

And my good sir, that was the question that was being answered.

Would removing the thermostat make it to cold.

Mission accomplished.

NO!!

SierraHD17 · March 16, 2020

On 3/14/2020 at 12:15 PM, truckguy82 said:

Yeah and any change in oil viscosity likely has a considerable effect on efficiency inside a transmission.

There’s a few reasons we get 25mpg+ highway, that’s one of them IMO.

Wrong again... direct injection is one of your leading achievements... lol. You keep believing you need that thermostat... but if you don't tow or do anything but just commute it won't really matter.. as much.

truckguy82 · March 16, 2020

11 hours ago, SierraHD17 said:

Wrong again... direct injection is one of your leading achievements... lol. You keep believing you need that thermostat... but if you don't tow or do anything but just commute it won't really matter.. as much.

So you are saying it doesn’t improve efficiency and that it serves no purpose

Fact is neither you nor I have any clue how much efficiency it gains

So my options are -

#1 - believe gm engineers that the efficiency gain is worth it

#2 - believe sierrahd17 from the truck forum who has zero data to support his claims

truckguy82 · March 16, 2020

12 hours ago, Grumpy Bear said:

Hey there Mister, I passed someone yesterday.

As you can see I tested in 5 mph increments between 30 mph and 75 mph.

Then I chose to gather data were is was most efficient.

So the data is not skewed. It represents the coldest possible temperatures.

And my good sir, that was the question that was being answered.

Would removing the thermostat make it to cold.

Mission accomplished.

NO!!

Whoa whoa whoa, you got up to 75mph!

Anyway thanks for the data.

Yeah that’s no too bad at all. I was more thinking like the northern states. In NJ the lowest we see is 0. I travel to VT a lot and we see probably -10 at the lowest. I was stationed in ND for a few years and we saw -25.

Should someone in ND remove the thermostat? Hell no. Should someone in VT remove their thermostat, no. Should someone in NJ remove their thermostat, eh maybe.

That was all I was trying to say.

SierraHD17 · March 16, 2020

1 hour ago, truckguy82 said:

Whoa whoa whoa, you got up to 75mph!

Anyway thanks for the data.

Yeah that’s no too bad at all. I was more thinking like the northern states. In NJ the lowest we see is 0. I travel to VT a lot and we see probably -10 at the lowest. I was stationed in ND for a few years and we saw -25.

Should someone in ND remove the thermostat? Hell no. Should someone in VT remove their thermostat, no. Should someone in NJ remove their thermostat, eh maybe.

That was all I was trying to say.

No you are just trying to argue based on using GM's engineering which we know is under constraint based off theoretical and usually laboratory fuel economy testing.... that's a fact. It's a terrible idea for people that tow and running your fluid at the high end of the scale degrades it with time and any oil manufacturer can show you that.. that's a fact.

Doesn't much matter anymore though lol.

Edited March 16, 2020 by SierraHD17

truckguy82 · March 16, 2020

22 minutes ago, SierraHD17 said:

No you are just trying to argue based on using GM's engineering which we know is under constraint based off theoretical and usually laboratory fuel economy testing.... that's a fact. It's a terrible idea for people that tow and running your fluid at the high end of the scale degrades it with time and any oil manufacturer can show you that.. that's a fact.

Doesn't much matter anymore though lol.

I have literally raced my friend while towing multiple times. I have never seen high temps in my trans.

I once towed a 15k lb dump trailer, i saw 205. Which is only 5 degrees over where it’s supposed to be.

i tow frequently and have never had an overheating problem with the trans thermostat active

please show me any data that suggest running modern gm trans fluid at 190-200 degrees (where it is with the oem trans thermostat) degrades it’s life. This is the basis of your arguement.

i already know the answer, you can’t find it. There is zero data to prove that it’s bad for the fluid. You are just guessing. I know all about the trans temp debate.

lab fuel economy testing lol. As if gm gives a shit about lab testing that doesn’t apply to the real world. You think they would spend a single extra penny on a trans thermostat if it wasn’t effective? If you don’t know the answer proven with data, and that’s where we are at, it’s naive to assume you know better than an army of engineers.

The only thing we know for sure is, the truck is built for all climates, so some modification to suit your particular climate is probably justified. Hence why I said the trans thermostat is more than useless if you live somewhere that you don’t see very cold temps.

Edited March 16, 2020 by truckguy82