Yes it does require more energy,the biggest factor though will be power(the rate at which the energy is transferred) you could obviously still heat both to 180f they would just reach that temp at different times and under different driving conditions.You calculate the time it takes to heat a object using Q=mcT

Q=energy required

m=mass(kg)

c=specific heat capacity(Joules)

T=(End Temp - Start Temp)temperature difference(K)

20qts example

m=18.9kg

c=2000joules

T=180F - 80F=310.9K

Q=18.9*2000*310.9

Q=11,752,020 Joules

using 74.569kw

time=157 seconds / 60 = 2.6 minutes

using 25hp = 18.625kw

time=630 seconds / 60 = 10.5 minutes

16qts

m=15.1kg

c=2000joules

T=180F-80F=310.9K

Q=15.1*2000*310.9

Q=9,389,180 Joules

using 74.569kw

time=125 seconds / 60 = 2 minutes

using 25hp = 18.625kw

time=504 seconds / 60 = 8.4 minutes

Now to find the time it will take to reach Q we need to know Power which would be the engine output at that moment.

Say are TC is unlocked making 100hp convert to watts 74,569w time=Q/p it would take 157seconds or 2.6minutes,now we arent taking into account heat loss,or the fact that power changes occur this is assuming all the energy is transferred via the ATF only and is a constant 100hp.Ideally a scenario were your TC is unlocked and your at low vehicle speeds would be city driving or stuck in traffic that would constantly have your power changing from stopping and going.Were as cruising on the highway your in a steady state plenty of wind flow,not that much power being used,and your TC is locked.

You also have to remember that the tradeoff you get with a deeper pan is it takes a longer amount of time to heat the fluid which in certain cases is good,but it will take more time to cool the 20qts then it would 16qts if the 20qts would be in a overheat condition.I personally would rather have the fast temperature changes,then add a extra cooler if my temps were getting to high.

Ok so I want to expand on this, because what I have found is actually very interesting. I would like to point out, that it is VERY possible I did the math wrong haha.

But, while the above was absolutely correct, Arny, it is only one piece of this equation. What we really need is an equation for "operating heat" not "start up heat" which was calculated above, although they are similar.

I apologize in advance, this equation uses Watts as the energy unit, but the equation proves an interesting point all the same.

Watt=

Weight of Material to be Heated (lbs) X Specific Heat (Btu/lb °F) X Temperature Rise (°F)

----------------------------------------------------------------------------------

3.412 Btu/watt hr. X Heat - up time (hr.)

So! using .45 as the specific heat for an oil, 100 degrees of temperature rise (80 to 180), and a heat up time using the values Arny got we get!

20qts: 4860 watts

16qts: 4853.57 watts

So as it turns out, the difference in the extra 4 qts is VERY negligible. I am actually incredible surprised by this, as I thought it would be way more. However, over a long period of time, those 7 watts of extra energy may actually make a huge difference, its hard to say.

Again I feel the need to point out that this equation is for Watts instead of Joules for energy, but it makes the point all the same. Other factors are important too, like the surface area of the deeper pan that allows more air flow etc. But its interesting to see the numbers. All in all, the deep pan helps, but not as much as we would probably like to think. I think its stronger pros are for more strength in the case, it looks sweet, easy to drain magnetic plug, and the sensor port.

Let me know anyone can see a flaw in the math

!