The 4L-80E

lch0 · January 31, 2005

I have an 04 GMC Z-71 with the 4L-60E and have had a GMC Duramax with the Allison trans. I now have my first experience with the 4L-80E in an 05 GMC 2500HD CC 4X4. This transmission is so different from the other two. In both the 4L-60E and Allison the first gears and overdrive gears ratios are pretty close. With the 4L-80E first gear is like 2:45 and the overdrive is somewhere around 0:75. This seems like it takes a lot of power to get it moving due to its high first gear and when you finally hit overdrive at 70 mph it taching around 2500 RPMs. It takes some getting used to this drivetrain and I can see where the mileage with this combo might not be that stellar. All in all it still seems to be a pretty healthy drivetrain just takes some getting used to.

To-Dmax · February 1, 2005

I have an 04 GMC Z-71 with the 4L-60E and have had a GMC Duramax with the Allison trans. I now have my first experience with the 4L-80E in an 05 GMC 2500HD CC 4X4. This transmission is so different from the other two. In both the 4L-60E and Allison the first gears and overdrive gears ratios are pretty close. With the 4L-80E first gear is like 2:45 and the overdrive is somewhere around 0:75. This seems like it takes a lot of power to get it moving due to its high first gear and when you finally hit overdrive at 70 mph it taching around 2500 RPMs. It takes some getting used to this drivetrain and I can see where the mileage with this combo might not be that stellar. All in all it still seems to be a pretty healthy drivetrain just takes some getting used to.

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I had one in a 1994 3500 6.5 Turbo diesel. The only problem was it was labeled on the door " Do not pull with trans in Overdrive" I bought an electric controled US Gear under drive unit to help protect the trans, & to help out the low powered motor. I sold the truck but kept the US Gear under drive just in case I would ever need it. I guess I should just sell it.

But to build a 1 ton truck, then not be able to pull in OD? I have not seen that problem with the newer trucks with the 4L80E.

vhato · February 1, 2005

I have a love/hate relationship with the 4L80-E transmission. I hate the 2.48:1 First gear, but love the 1-2-3 close ratios and smooth shifts. I hate the 0.75:1 OD ratio, but love how I can haul a light load in OD with no problems.

Of course it was the same way with the 4L60-E when I had a 1/2 ton.

I LOVED the 3.06:1 First Gear, but HATED the horrible transition during the 1st to 2nd up shift. I LOVED the wonderful fuel siping 0.69:1 OD ratio, but hated how even a light load would cause the computer to pull it out of OD and into 3rd.

My '04 2500HD Crew Cab averages on my daily work commute a 13.3 MPG Tank. Our current fuel prices place me at a fuel cost of $0.14 per mile. A co-worker owns an '04 1500 Crew Cab and his fuel costs are LESS THAN $0.01 per mile. In his truck my work commute would save me nearly $700.00 per year, not including a lower note and lower insurance. I LOVE my 2500HD, but the mathematics kinda put me in my place.

ctfan · February 1, 2005

I have a love/hate relationship with the 4L80-E transmission. I hate the 2.48:1 First gear, but love the 1-2-3 close ratios and smooth shifts. I hate the 0.75:1 OD ratio, but love how I can haul a light load in OD with no problems.

Of course it was the same way with the 4L60-E when I had a 1/2 ton.

I LOVED the 3.06:1 First Gear, but HATED the horrible transition during the 1st to 2nd up shift. I LOVED the wonderful fuel siping 0.69:1 OD ratio, but hated how even a light load would cause the computer to pull it out of OD and into 3rd.

My '04 2500HD Crew Cab averages on my daily work commute a 13.3 MPG Tank. Our current fuel prices place me at a fuel cost of $0.14 per mile. A co-worker owns an '04 1500 Crew Cab and his fuel costs are LESS THAN $0.01 per mile. In his truck my work commute would save me nearly $700.00 per year, not including a lower note and lower insurance. I LOVE my 2500HD, but the mathematics kinda put me in my place.

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Just don't worry about the numbers, remeber its an HD

William

vhato · February 1, 2005

I don't worry about it at all, but it helps understand just exactly how much truck I have.

Mark_in_Tulsa · February 1, 2005

Could someone please post all the gear ratios of the 4L60-E, and 4L80-E, and even the Ally.

fastdrvr23 · February 1, 2005

Could someone please post all the gear ratios of the 4L60-E, and 4L80-E, and even the Ally.

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I only know the 4L60, but maybe I can help with it:

1st -> 3.06

2nd -> 1.75

3rd -> 1.00

4th -> 0.70

BigBlockHead · February 1, 2005

My '04 2500HD Crew Cab averages on my daily work commute a 13.3 MPG Tank. Our current fuel prices place me at a fuel cost of $0.14 per mile. A co-worker owns an '04 1500 Crew Cab and his fuel costs are LESS THAN $0.01 per mile. In his truck my work commute would save me nearly $700.00 per year, not including a lower note and lower insurance. I LOVE my 2500HD, but the mathematics kinda put me in my place.

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I'm assuming you meant your co-worker's fuel cost was less than $0.10 per mile. Otherwise he's making 186MPG.

You have to buy the truck that will do the biggest job you have to do with it. Then if you can justify a second vehicle as a daily driver you do it. $700/yr doesn't go very far towards a second vehicle when you figure payments, insurance, maintenance, repairs, etc. Just my $0.02, or is it $0.20?

dewfpo · February 1, 2005

4L80E

1 - 2.482

2 - 1.482

3 - 1.000

4 - 0.750

R - 2.077

Allsion 1000

1 - 3.10

2 - 1.81

3 - 1.41

4 - 1.00

5 - 0.71

R - 4.49

DEWFPO

Shawn T · February 1, 2005

4L80E

1 - 2.482

2 - 1.482

3 - 1.000

4 - 0.750

R - 2.077

Allsion 1000

1 - 3.10

2 - 1.81

3 - 1.41

4 - 1.00

5 - 0.71

R - 4.49

DEWFPO

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Look at those ratios on the Alli. Reverse is awesome for backing up heavy trailers. Allison kicks a$$. I'm sure glad I have one.

vhato · February 1, 2005

Thanks BigBLockHead,

That was right. $0.10 per mile. His cost for my trip would be $5.70 per day where as mine is $7.98. Roughly $600 a year. Not $700. I dunno where my head was.

jamashke · February 1, 2005

Thanks BigBLockHead,
That was right. $0.10 per mile. His cost for my trip would be $5.70 per day where as mine is $7.98. Roughly $600 a year. Not $700. I dunno where my head was.

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How in the world are you getting 13.3 mpg with your 2500? How many miles do you have on it? Any type of tunes?

vhato · February 1, 2005

No tune, no mods, all stock, 15,000 miles.

I drive 57 miles to work both ways. This includes stop and go traffic in 11 consecutive stop lights and some nice long highway sprints between 65 and 70MPH.

During my trip to work I do my very best not to exceed 2000 RPM during acceleration in 1st, 2nd and 3rd gears. I modulate my throttle until I get into 4th and reach the speed I want. In 4th @ 70 MPH I am passed 2000 RPM. Somewhere around 2300-2500 RPM.

This USUALLY results in 14.0 -14.3 MPG on my commute. However, I get aggressive somtimes and pass alot of people so that brought me down to 13.3 MPG for this last tank full.

Interstate driving doing 75 MPH usually gets me around 350 miles before the low fuel light comes on. That is roughly 16 MPG on 22 gallons of fuel.

Do a fill up and do your best not to exceed 2000 RPM (except in OD..go as fast as you want) while accelerating for the entire tank and I am sure you will see an improvement. About once a month this gets boring for me.

maverickseb · February 1, 2005

How many gallons are left in your tank when the "low fuel" light comes on?

vhato · February 2, 2005

How many gallons are left in your tank when the "low fuel" light comes on?

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That is weird, on my truck the low fuel light comes on when I have consumed between 21.5 or 22 gallons of fuel. I have never seen it anyway else. Never more and never less. So I figure 4 gallons till dead. Probably less.