chevy 4spd vs 6spd in 1500


26 replies to this topic
  • ulmanb

Posted June 04, 2009 - 02:09 AM

#1

What are the good pts/bad pts of going with a 6 speed tranny vs a 4 speed tranny in the new chevy/gmc?

All I know is that the 6 spd is supposed to get better mileage and costs about $1000 more.

  • The Wylde One

Posted June 04, 2009 - 02:22 AM

#2

6 Speed better Fuel economy and you will get better 0 to 60 times

  • stevenacarter77

Posted June 04, 2009 - 03:17 AM

#3

if that 4 speed has a grunt granny 1st gear better off road for pulling wagons, ect, stronger with no overdrive, less parts; well that is the way it use to be with the iron case 4 speed and a iron case 205 transfer case; indestructible in the 1970s lol

  • Mikek671

Posted June 04, 2009 - 05:21 AM

#4

I would get the 6 speed hands down, my 03 1500 has the 4 speed with a 4.10 rear and although it does OK towing I wish it had better gearing for everything when towing/hauling. I have driven and towed with my friends Titan (5 speed) and my brothers new Tundra (6 speed) and they are both so much better at towing/hauling with the extra gears. As others have mentioned it will get better mileage but having the correct gearing for all situations is even more important.

  • Smacaroni

Posted June 04, 2009 - 10:14 AM

#5

My opinion:
Diesel: six, gas: four unless you plan to do little towing or hauling in which case the extra cost on the six will pay for itself many times over in gas savings. This assumes the EPA estimates are pulled out of a scientist's ass instead of an executive's ass, cause EPA estimates suck.
Either way you're looking at a device that should last about 300,000 miles longer than a similar automatic. No less than 50,000 miles longer before you even have to look at the thing unless you do a lot of burn outs.

  • Chevy_Cowboy

Posted June 04, 2009 - 10:18 AM

#6

My opinion:
Diesel: six, gas: four unless you plan to do little towing or hauling in which case the extra cost on the six will pay for itself many times over in gas savings. This assumes the EPA estimates are pulled out of a scientist's ass instead of an executive's ass, cause EPA estimates suck.
Either way you're looking at a device that should last about 300,000 miles longer than a similar automatic. No less than 50,000 miles longer before you even have to look at the thing unless you do a lot of burn outs.



GM's automatics are some of the best in the industry (especially the allison behind the deisel) but even they wont typically last 300,000 miles. That territory is reserved only for manual boxes.

  • Smacaroni

Posted June 04, 2009 - 10:20 AM

#7

That's assuming the fluid is changed and filters and any periodic adjustments made as well. Far too many automatics die not only because they're hot and under rated, but because it's compounded by lack of maintenance.

As far as any tranny behind a diesel... a diesel engine should last 500,000 miles minimum. The big ones should go three times that. At which point a big rig will probably gasp and die cause sometimes work horses do that.

  • Chevy_Cowboy

Posted June 04, 2009 - 11:00 AM

#8

even for a well maintained slushbox, 300k is pretty unheard of. 200 is more like it, after that they're gonna need some work.

Diesel engines hold up great, they just tend to be hard on the tranny behind them. The allison is by far the best automatic ever built but even it wont last nearly what the engine will.

  • DMC707

Posted June 04, 2009 - 11:18 AM

#9

My '08 2500 (6.0 liter, 6 speed) averages 16 mpg and can clock 18 on a flat highway

Most of my aquaintances with the 4 speed behind this engine in the '06-down body style trucks report no better than 12 mpg usually.
I cant vouch for towing performance because i havent driven one, but a 4 mpg difference is pretty good

  • Chevy_Cowboy

Posted June 04, 2009 - 11:28 AM

#10

My '08 2500 (6.0 liter, 6 speed) averages 16 mpg and can clock 18 on a flat highway

Most of my aquaintances with the 4 speed behind this engine in the '06-down body style trucks report no better than 12 mpg usually.
I cant vouch for towing performance because i havent driven one, but a 4 mpg difference is pretty good



The 6.0 greatly benefits from the extra gears too. The 6.0 4 speed with 3.73 rears feel pretty gutless on takeoff. Even just a single extra gear like my 5 speed helps, but 6 let the truck have plenty of low end grunt yet gearing for good mileage at highway speed.

  • KDXtreme200

Posted June 04, 2009 - 12:27 PM

#11

I myself would go with the six speed. But my dad seems to think that the 6 speed has no powerband. And would strongly prefer the four speed.

  • witdogg

Posted June 04, 2009 - 12:35 PM

#12

What are the good pts/bad pts of going with a 6 speed tranny vs a 4 speed tranny in the new chevy/gmc?

All I know is that the 6 spd is supposed to get better mileage and costs about $1000 more.


I've personally used both for towing and everyday driving and if you are going to use the vehicle for towing the extra cost of the 6 speed is worth it. If you won't be using it for towing I wouldn't waste money on it in hopes of getting it back on better gas mileage.

  • The Wylde One

Posted June 04, 2009 - 02:07 PM

#13

Ok Im sorry. But I have to say Allison Transmissions Suck. My Dad sells Truck Parts for a Living for Big Rigs but also supplies any part Trans Turbo Charger clutch etc etc for Any Diesel engine And some car parts to. He gets numerous customers who come in and are always buying parts for Allison Trans. And alot of These people that come in are Mechanics and some private owners.

  • rustyknife

Posted June 04, 2009 - 04:09 PM

#14

Im gonna have to ditto the above poster, the allison 1000 tranny is a joke. The torqshift, now thats a transmitter

  • brad the best

Posted June 04, 2009 - 05:04 PM

#15

Ok Im sorry. But I have to say Allison Transmissions Suck. My Dad sells Truck Parts for a Living for Big Rigs but also supplies any part Trans Turbo Charger clutch etc etc for Any Diesel engine And some car parts to. He gets numerous customers who come in and are always buying parts for Allison Trans. And alot of These people that come in are Mechanics and some private owners.


nothing lasts forever . i don't think they are worse then any other truck tranny but i don't think they are any better ether .


i would definitely get a 6 speed over a 4 speed , the only benefit of a 4 speed is that it is smaller , this is only applicable if you are swapping a drive line into something with a short wheel base . ex my 4 speed is 11" long compared to a 6 speed at around 2 feet . and of course as you have learned cost .

again if i was buying a new truck , 6 speed hands down .

  • offroadrider12

Posted June 04, 2009 - 05:40 PM

#16

He's saying trans for a 1500, so the allison doesn't apply. What 4 speed are we talking about, the 4L60E or are they offering the 4L80E in the new ones? The 6 speed is most likely the 6L80E or 6L90E. Forget the 4L60E, they're good for puking themselves onto the ground, that's about it, not a good truck trans. The 4L80E transmission is BULLETPROOF, some guys can make a stock 4L80E hold 800 HP for quite a while, the 4L80 is pretty much a TH400 with overdrive. The 6L80E & 6L90E are strong transmissions from what I hear, I also have heard they don't like to pick a gear to stay in unless you get a good custom tune from someone like justin @ blackbear performance.

  • Chevy_Cowboy

Posted June 04, 2009 - 11:35 PM

#17

Ok Im sorry. But I have to say Allison Transmissions Suck. My Dad sells Truck Parts for a Living for Big Rigs but also supplies any part Trans Turbo Charger clutch etc etc for Any Diesel engine And some car parts to. He gets numerous customers who come in and are always buying parts for Allison Trans. And alot of These people that come in are Mechanics and some private owners.



Do ya have any idea how many allison transmissions there are in the world? Not just in GM trucks... but buses, campers, and medium duty trucks often have Allisons. Of course you're gonna sell some parts for a brand thats in a couple million vehicles.

  • Chevy_Cowboy

Posted June 04, 2009 - 11:57 PM

#18

He's saying trans for a 1500, so the allison doesn't apply. What 4 speed are we talking about, the 4L60E or are they offering the 4L80E in the new ones? The 6 speed is most likely the 6L80E or 6L90E. Forget the 4L60E, they're good for puking themselves onto the ground, that's about it, not a good truck trans. The 4L80E transmission is BULLETPROOF, some guys can make a stock 4L80E hold 800 HP for quite a while, the 4L80 is pretty much a TH400 with overdrive. The 6L80E & 6L90E are strong transmissions from what I hear, I also have heard they don't like to pick a gear to stay in unless you get a good custom tune from someone like justin @ blackbear performance.


Most the half tons are 4L60's or 6L80s. The 1500s with the 6.0 or 6.2 get a 4L65.

  • offroadrider12

Posted June 05, 2009 - 10:04 AM

#19

Most the half tons are 4L60's or 6L80s. The 1500s with the 6.0 or 6.2 get a 4L65.


Yep, some of the old body style trucks got the 4L80E, wasn't sure if they did that to the New body styles at all? I just plain am not fond of the 4L6XE series, so I would get the 6L80E, especially since its much stronger.

  • Chickenhauler

Posted June 06, 2009 - 11:20 AM

#20

Ok Im sorry. But I have to say Allison Transmissions Suck. My Dad sells Truck Parts for a Living for Big Rigs but also supplies any part Trans Turbo Charger clutch etc etc for Any Diesel engine And some car parts to. He gets numerous customers who come in and are always buying parts for Allison Trans. And alot of These people that come in are Mechanics and some private owners.


Stop and think-Allison trans are the choice for many "vocational" applications-cement mixers, dump trucks, boom trucks, garbage trucks, etc.

Think about the abuse and use these transmissions see compared to an Eaton 13spd in a long haul road application....mine rides in top gear for 4-5 hours at at time. In that same time period, an Allison in a garbage truck may make as many as 500 gear shifts.


Do ya have any idea how many allison transmissions there are in the world? Not just in GM trucks... but buses, campers, and medium duty trucks often have Allisons. Of course you're gonna sell some parts for a brand thats in a couple million vehicles.


Not just a "couple" they passed the 5,000,000th commercial transmission back in 07. That's not even counting their light duty stuff (GM PU's).

Don't forget that Allison is the transmission of choice for the 1500 hp 140,000 lb M1 Abrams tank.




 
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