# hows the 6.6 duramax



## the new boss 92 (Nov 29, 2008)

http://www.lenzauto.com/FS.aspx?Dis...browse2.asp&URLParameters=param_new-used=used

i have been looking at this truck, but i havent heard a whole lot about the 6.6 duramax motors. it wont have any chips done to it just an exhaust maybe an intake, but for the most part it will stay stock and wont be driven a whole lot due to the fact that i will still have my 1500. what are your thoughts on this truck, any big downers about the motor?


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## the new boss 92 (Nov 29, 2008)

put 2500 in the search up top and its the 7th one down on the page, the direct link isnt working for some reason! also from the looks it might have the plow prep to i havent looked into it to much though because i dont know about the motor.


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## NoFearDeere (Nov 7, 2005)

All GM trucks have the 6.6 Duramax except when you get up to Kodiak 5500's and above then you can run across a few 7.8 Duramax' s or CAT motors. I dont know exactly which one your looking at but Duramax's are good trucks.


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## JustinD (Jan 14, 2008)

I love mine!!!!!


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## the new boss 92 (Nov 29, 2008)

08 lt1 package and its a z71, 28000 miles for 36995. do you guys have any problems with your or are they all around a good motor. i own a goverment motor now


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## JustinD (Jan 14, 2008)

08 has the LMM engine, awesome motor, though the DPF will cut down on the mileage, if you aren't worried about the warranty I would do a DPF delete and use a tuner of some sort to turn the DPF off, you will see a HUGE increase in mileage. Sounds like an awesome truck.


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## ondagawood (Sep 19, 2007)

JustinD;942647 said:


> I love mine!!!!!


*AMEN - X2*


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## sno commander (Oct 16, 2007)

i dont think any 08's have the plow prep with the d-max /extended cab. nice truck the d-max is a great motor
the price seems high though


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## dmaxplowguy66 (Dec 10, 2009)

Love my 02 DMAX! 185,000 miles water pump at 145,000 ,wheel bearing last week and thats it. I would buy another in a heartbeat and am actually thinkin about another one this summer! Cant see the one your looking at but I would shoot for an 2006 model. Best motor and drivetrain. It has the LBZ code engine and 6speed auto. Your gonna get the better mpg out of the 06 as well. 01 and some 02's had injecter problems but thats about it really. and 04 to half 06 had LLY motors and have a overheating problem towing sometimes. I would'nt get a 07 or newer due to the frame brakeage problem were seeing on here?? oh and trust me you'll have a chip in that thing with in a year! lol I said the same thing when I first got mine! lol


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## jomama45 (Dec 25, 2008)

the new boss 92;942301 said:


> http://www.lenzauto.com/FS.aspx?Dis...browse2.asp&URLParameters=param_new-used=used
> 
> i have been looking at this truck, but i havent heard a whole lot about the 6.6 duramax motors. it wont have any chips done to it just an exhaust maybe an intake, but for the most part it will stay stock and wont be driven a whole lot due to the fact that i will still have my 1500. what are your thoughts on this truck, any big downers about the motor?


I only have an older D-Max, so I don't have any info on that end. BUT, be carefull with Lenz. Prices are usually high & non-negotiable. I've bought from them once, & know of a few others that have as well. They're not the most professional IMO. Unfortunately, they buy almost every Diesel truck that comes into the auctions, which is why they have a huge selection, & no one else around here seems to have any.

Good Luck.


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## got-h2o (Sep 26, 2008)

I'm on my 6th and am currently looking for an LMM myself. As far as that goes, all brands currently use a DPF and its easily eliminated if it bothers you. I could have picked any truck(s) I wanted, and Dmax will always get my vote for #1.


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## aeronutt (Sep 24, 2008)

I can't believe nobody has suggested you spend a year or two reading at www.dieselplace.com yet... You'll find more good info than you could ever hope for.

I have the 06 LBZ and really like it. I pull a heavy camper in the summer and plow with it in the winter. When I don't need it for "truck stuff", it sits in the driveway while I drive my sedan.

If I was looking at buying a truck mostly for plowing, planned to park it most of the time, and keeping the 1500 for being my "town truck", I wouldn't even consider a d-max. However, if you plan on pulling heavy trailers all over the country in the summer, there isn't a better truck on the market for that. Don't buy a diesel thinking you'll save money on gas either. The diesel (even with DPF delete and a tuner) won't save you money in the long run. It's claim to glory is pure horsepower and reliability to get the job done.


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## ohiogreenworks (May 31, 2009)

I have always been a cummins fan but I really really like our 03 dmax. I have also seen dmax pulling trucks with 1k+ horsepower and they run awesome. I do know that the new emissions sh*t they brought up in 07.5 really really hurts mileage on all the big 3 diesels. As was mentioned before the dpf delete is good. My old boss had an 08 6.4 powerstroke and it got 9-10mpg loaded to the hilt or unloaded with just me driving. Emissions = suckage


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## the new boss 92 (Nov 29, 2008)

ok well ill keep looking.


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## VPRacing (Dec 26, 2009)

Just snapped the crank shaft on our 6.6 Duramax in a 03 Kodiak 4500. Dont have any idea how it happened but I have heard it happening before. Its a 2wd Automatic so its kinda hard to be abusive to the crank.

It pulls a 15k - 44ft gooseneck trailer daily. Plenty of oil, who knows what could have made it snap, maybe this was a motor assembled on Friday at 4pm.


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## mjp2 (Dec 29, 2009)

I love my DMax, ever since I drove it off the lot 9 years ago. If you own one, trust me, it won't be long before it's "stock" status starts to fade. These things are absolute beasts. When mines not towing or plowing, it likes to beat down tuners and even the occasional mustang. (yes....GT's includedwesport)


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## the new boss 92 (Nov 29, 2008)

yea well i have alway put exhaust on my rigs so that will be the first thing to do, how ever the programmer might come in the long run, but i dont see it happening right after i buy one.i have always been a chevy fan and dont get me wrong the cummins are nice trucks to jsut not a strong believer in dodge. i have to keep my eye out for something special because im in need of a 3/4 ton for plowing and i really dont want another gasser but havent really looked at the gassers that much.


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## Yaz (Apr 13, 2005)

Nothing bad to say here.. Love my Duramax. Plows better than my old gas version because the engines torque is just incredible.


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## 02DURAMAX (Dec 27, 2006)

I love my Duramax's!!!!! Not one problem with them ever!


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## NoFearDeere (Nov 7, 2005)

I cant really say anything good about Lenz, they wont negotiate and kinda insult you when it comes to dealing. I tried dealing a few times and they sucked.


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## lawn king (Nov 21, 2004)

I just turned 41000 on my 2008 lmm. Universals front & rear were cooked at 30 k and replaced under warranty, other than that its been awesome. Love the allison 6 speed.


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## the new boss 92 (Nov 29, 2008)

Yea everything I heard about lenz is garbage but they do have nice trucks and all. I'm going to call them when it comes time to dealing before I take a trip up there. Any one know of a good place to by diesiels in the midwest? I'm window shoping now but if I find something I can't pass up then ill jump on it


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## Stik208 (Oct 19, 2004)

Thats quite a few peppers for that vehicle. I know everyone wants a diesel a vortec 6.0 is a good strong motor for plowing and would be 1/2 the price.


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## ohiogreenworks (May 31, 2009)

I have had great luck with my 6.0 gasser. Great power, it pushes side by side by the dump with the dmax. The 6.0 has plenty of torque and it gets going in a hurry. From what I have seen around chicago you are going to be paying quite a bit more for diesel too....I dunno maybe out where you are its cheaper. 

As for where to shop, check ebay. I know its ebay but my dad and I have bought probably 10 vehicles on there. We usually bid on them and win it then go look at it before we pay. Obviously this works on vehicles that are not all the way across the country. It has worked for us, just becareful but you can usually find some deals.

Also, trucktrader.com usually has some decent deals. If you are ready to shell out that kinda dough you will be able to find a truck for sure!


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## blowerman (Dec 24, 2007)

I have two Duramax trucks and love them. The engine with allison combo is one of my favorite set ups and I do own the other brands. As for Lenz, it's hard to beat their selection, but they are not very professional and could care less to deal! I have bought one truck from them, just don't think I'd buy another!


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## yamahartx (Dec 24, 2009)

I would try autotrader. List the price you want to spend, location..bla bla. Atleast you can see what others are selling them for.

BTW, love my duramax!


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## Kelsey (Dec 12, 2009)

Just wondering, what are the duramax's running as far as gallons per hour plowing?


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## cubanb343 (Dec 13, 2007)

I absolutely love mine! But that one looks expensive. I wouldn't want to pay more than 30k for a used 3/4 ton..


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## ConnorExum (Jan 5, 2010)

Aren't the Duramax's made by International ??? I really really like their DT 466 series engines...


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## cubanb343 (Dec 13, 2007)

International made Powerstrokes


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## 02DURAMAX (Dec 27, 2006)

Kelsey;952490 said:


> Just wondering, what are the duramax's running as far as gallons per hour plowing?


Depending on how heavy my foot is im at 1gal an 1Hr. to .1.10Gal an 1Hr.


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## cubanb343 (Dec 13, 2007)

02, mine is running right about the same.. about 1 gallon or a little more per hour. This includes idling at home, driving to the shop, idling there, BSing for awhile, then going to work. But all in all, same ballpark of a gallon or so per hour.


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## aeronutt (Sep 24, 2008)

I pushed for 20 hours on a tank over Christmas. Took 26 gallons to refuel.


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## lawn king (Nov 21, 2004)

ConnorExum;952550 said:


> Aren't the Duramax's made by International ??? I really really like their DT 466 series engines...


The duramax diesel was designed & built in a joint effort between general motors and isuzu engineering, a gand slam for sure. I own the 4th generation the LMM engine, the 5th generation is due out next year.


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## cubanb343 (Dec 13, 2007)

aeronutt;953092 said:


> I pushed for 20 hours on a tank over Christmas. Took 26 gallons to refuel.


There are so many variables that make it hard for me to do the math. I usually do the same route, but throw in a few extra places, some more driving here to there and back, blah blah blah. Then heavy snow vs. light fluffy snow.. catch my drift? pun intended. Add to this mystery now, my check engine light came on last week and it's an EGR issue. So that I'm sure doesn't help the fuel mileage. But even with that I'm still killing the gas trucks I work with on fuel efficiency. They're going thru at least 10 gallons or so while I've gone thru 6.


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## ConnorExum (Jan 5, 2010)

lawn king;953166 said:


> The duramax diesel was designed & built in a joint effort between general motors and isuzu engineering, a gand slam for sure. I own the 4th generation the LMM engine, the 5th generation is due out next year.


Interesting... I thought it was an International Product. How much does a Duramax weigh I wonder? I bet my LDT-465-1D engine in my M35A2 weighs more but produces half the torque and 1/3 the horsepower. I mean it is 7.8liter engine but it only makes 140hp @ 2600rpm and 305ft-lbs of torque @ 1500rpm but weighs in 1650lbs. I'm curious if this engine is so heavy compared to the lighter Duramax and Powerstroke engines what is difference in life span? Also my engine has an insanely high compression ratio of 22:1 and it has a turbo on it to boot. So after the turbo starts working it must be in the 25-28:1 range easily. But really I'm curious do you guys see more wear in these small lighter weight engines?


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## aeronutt (Sep 24, 2008)

It's not really a fair comparison to the heavy truck engines. The D-Max still weighs in around 1200 lbs, but it's not intended to make 70-80% of it's max power continuously for days on end. In most applications, it only makes that much power for less than 10% of it's lifespan. Some people run them harder running hot-shot operations and manage to have them last a good while before failure, but looking at average use for the hundreds of thousands of them running around they are plenty reliable for how they get used. If you need an engine to produce 350 HP for 8 hours at a time day-in and day-out, Cat and Cummins both make engines that work great for that. They weigh 4K+ and sit in Class 8 trucks.


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## ConnorExum (Jan 5, 2010)

aeronutt;953491 said:


> It's not really a fair comparison to the heavy truck engines. The D-Max still weighs in around 1200 lbs, but it's not intended to make 70-80% of it's max power continuously for days on end. In most applications, it only makes that much power for less than 10% of it's lifespan. Some people run them harder running hot-shot operations and manage to have them last a good while before failure, but looking at average use for the hundreds of thousands of them running around they are plenty reliable for how they get used. If you need an engine to produce 350 HP for 8 hours at a time day-in and day-out, Cat and Cummins both make engines that work great for that. They weigh 4K+ and sit in Class 8 trucks.


I was just curious actually. Just making small talk.  I was just curious what the life span of the Duramax was. Of course I love a good big 855cid Cummins, I'm even a fan of the small-bore 743cid Cummins. In fact I'm looking a nifty Oshkosh with a NH220 in it. But really I was just curious what sort of life span people were getting out these smaller-lighter but high output diesel engines.


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## tuney443 (Jun 25, 2006)

ConnorExum;953334 said:


> Interesting... I thought it was an International Product. How much does a Duramax weigh I wonder? I bet my LDT-465-1D engine in my M35A2 weighs more but produces half the torque and 1/3 the horsepower. I mean it is 7.8liter engine but it only makes 140hp @ 2600rpm and 305ft-lbs of torque @ 1500rpm but weighs in 1650lbs. I'm curious if this engine is so heavy compared to the lighter Duramax and Powerstroke engines what is difference in life span? Also my engine has an insanely high compression ratio of 22:1 and it has a turbo on it to boot. So after the turbo starts working it must be in the 25-28:1 range easily. But really I'm curious do you guys see more wear in these small lighter weight engines?


Not only are you comparing apples to oranges regarding different sized trucks,you're also comparing older vs. newer engines.Newer diesel engines in the pickup to a 550/5500 size range don't rely on extremely high compression anymore.Very high fuel pressure,common rails,superior injection are just some of the latest engineering upgrades to all 3 brands of diesels in the last 10 years or so.Your having a turbo on the 7.8 doesn't increase your compression ratio,it simply gives you more power by increased free waste air giving a boost.All 3 brands also all have turbos,except for some older PS's and Cummins.To answer your question on longevity,there's some members on the DP that have over 300K miles on their Dmax's who almost exclusively ''hot shot'' their pickups,pulling 3 cars on car trailers and huge RV's for a living.


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## JustinD (Jan 14, 2008)

I too plowed for about 20hrs on a single tank, (26gal) I also did my driveways afterwards. If anyone has any question to the durability of these engines take a ride down to a town called Tiverton RI there are about 10-15 of these trucks here (owned by younger guys 19-early 30's) most of them are EFI tuned with decent hp numbers, and they keep going, not to say no one has broken anything, but alot of abuse on these engines and we all still love em!!!!!!!! Everthing from 5500's with plows and sanders to reg cab work trucks to ext cab and crew cab 12 second demons!!!!!! From truck pulling to drag racing to hauling 18k boats, mine has done it all. I wouldn't trade it for any other brand diesel today.


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## ajchuck (Sep 11, 2008)

I love my 03 LB7! I have yet to have a real big problem with it and I have 106K on the clock. Just bought an 84 GMC 6.2 Diesel plow truck to save my 03 as my good daily driver.


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## Quality SR (Oct 25, 2006)

ondagawood;942670 said:


> *AMEN - X2*


x3......



mjp2;943530 said:


> I love my DMax, ever since I drove it off the lot 9 years ago. If you own one, trust me, it won't be long before it's "stock" status starts to fade. These things are absolute beasts. When mines not towing or plowing, it likes to beat down tuners and even the occasional mustang. (yes....GT's includedwesport)


Ditto. 



cubanb343;952754 said:


> International made Powerjoke


Fixed it for ya............................ :laughing: 


Yaz;943627 said:


> Nothing bad to say here.. Love my Duramax. Plows better than my old gas version because the engines torque is just incredible.


I love mine. It pushes my Boss V with a pile of snow infront of it like it was nothing. I wouldnt buy anything but Duramax.


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## cubanb343 (Dec 13, 2007)

Mine plows like an absolute tank.. NO complaints here


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## OldCrow (Dec 14, 2009)

We have a couple 4500's with the DM. Beasts. Plus with the Allison, you can't beat it.


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## ConnorExum (Jan 5, 2010)

aeronutt;953491 said:


> It's not really a fair comparison to the heavy truck engines. The D-Max still weighs in around 1200 lbs, but it's not intended to make 70-80% of it's max power continuously for days on end. In most applications, it only makes that much power for less than 10% of it's lifespan. Some people run them harder running hot-shot operations and manage to have them last a good while before failure, but looking at average use for the hundreds of thousands of them running around they are plenty reliable for how they get used. If you need an engine to produce 350 HP for 8 hours at a time day-in and day-out, Cat and Cummins both make engines that work great for that. They weigh 4K+ and sit in Class 8 trucks.


Well actually I'm curious how these small engines with extreme pressures last so long. Conventional wisdom in diesel engine diesel is that the greater the pressure on the engine requires an increase in overall weight of the engine for maximum life span. So I was curious as to how they are making so much horsepower and if this cuts into the life span of the engine in a noticeable sense.

As for the turbo can be used for lots of reasons on a diesel. In the case of the LDT-465-1D engines it was used for two reasons: improve the fuel air mixture to the rear cylinders and cut down on exhaust. That is why the engine doesn't have a really much of a dish on the piston, because the goal is not so much raw hp but to equalize the fuel air mixture through out the cylinder head. Of course by increasing the internal pressure of the cylinder head before the piston compresses the air the engine increases it's overall compression ratio. For example Top Fuel dragsters increase the volume of the cylinder head by using a deep-dish or concave piston design that will allow the supercharger to make up for the increased volume without blowing up the engine. Remember a Turbo produces no boost when the engine starts up. In fact it produces very little boost when the engine the is idling. It requires a specific exhaust volume to properly work: turbo lag.

But really my conversation was just the awe of new engines and how radically different technology is today over that of vehicles even 30 years ago. But really I think the question is why does a truck the size of a Chevy 2500 need 365hp in the first place? How faster is it going to do the work with a load over that of a say a 200hp or 250hp truck? I think what we are seeing in lot of the development of these vehicles is one up-manship merely to say our truck makes 400hp and yours doesn't.

However, I would like to know more about the Duramax's... I'm a big fan of diesels.


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## aeronutt (Sep 24, 2008)

ConnorExum;957654 said:


> ... why does a truck the size of a Chevy 2500 need 365hp ... development of these vehicles is one up-manship merely to say our truck makes 400hp and yours doesn't.


Bullseye. Bragging rights sells trucks. I love having all that power on tap for the two and a half-second squirt of speed I need once a year when I pull out into traffic that I should have waited for, but realistically my truck would still be perfectly capable of doing it's job with 250 HP. I'd just have to wait a little longer for traffic to clear once in a while. My uncle ran an International flatbed truck pulling a triple-axle gooseneck loaded with 25-30K worth of hay on only 185 HP for years. That engine was maxed out for 80% of it's life, but still managed to last at least 15 years and 400,000 miles. Since my engine produces less than 200HP 99.9% of the time, that infrequent burst of 365 (well, closer to 435 with the tuner... ) just doesn't have a chance to cause much wear.


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## blueline38 (Dec 22, 2007)

*Lenz*

It looks like they have many nice trucks however I looked up a few in Edmunds and they are $3k - $4k over priced. If they aren't willing to negotiate then I would not buy from them. Just my $.02!


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## ConnorExum (Jan 5, 2010)

aeronutt;957718 said:


> Bullseye. Bragging rights sells trucks. I love having all that power on tap for the two and a half-second squirt of speed I need once a year when I pull out into traffic that I should have waited for, but realistically my truck would still be perfectly capable of doing it's job with 250 HP. I'd just have to wait a little longer for traffic to clear once in a while. My uncle ran an International flatbed truck pulling a triple-axle gooseneck loaded with 25-30K worth of hay on only 185 HP for years. That engine was maxed out for 80% of it's life, but still managed to last at least 15 years and 400,000 miles. Since my engine produces less than 200HP 99.9% of the time, that infrequent burst of 365 (well, closer to 435 with the tuner... ) just doesn't have a chance to cause much wear.


It is impressive to see a truck the size of a Chevy 2500 with as much Hp in it as say a Peterbilt with a GCVW of 120,000lbs. What do you think the cylinder pressure is of the Duramax 6.6l at 3100rpm is when this truck is making 365hp? It has to be really high.

Are all the Chevy trucks now automatic? I was just curious if I could find out more about the engine and I went to the Chevy/GMC homepages and well all I found were autos. No one is a fan of the manual gearbox in these smaller trucks any more or is it a dealer special order option these days?


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## tuney443 (Jun 25, 2006)

ConnorExum;957857 said:


> It is impressive to see a truck the size of a Chevy 2500 with as much Hp in it as say a Peterbilt with a GCVW of 120,000lbs. What do you think the cylinder pressure is of the Duramax 6.6l at 3100rpm is when this truck is making 365hp? It has to be really high.
> 
> Are all the Chevy trucks now automatic? I was just curious if I could find out more about the engine and I went to the Chevy/GMC homepages and well all I found were autos. No one is a fan of the manual gearbox in these smaller trucks any more or is it a dealer special order option these days?


Well,not quite the same HP.Usually,a Pete these days is around 500-575 HP.,but the huge difference is in torque.Some of these engines are up in the 1500 ft. lbs.class--the newest Dmax is app. 660ft. lbs.

Manuals haven't been available for a couple of years now,the Allison 6 speed auto.with tow haul and manual shifting ability,besides being almost bulletproof, put a fork in the manual tranny.


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## ConnorExum (Jan 5, 2010)

tuney443;957892 said:


> Well,not quite the same HP.Usually,a Pete these days is around 500-575 HP.,but the huge difference is in torque.Some of these engines are up in the 1500 ft. lbs.class--the newest Dmax is app. 660ft. lbs.
> 
> Manuals haven't been available for a couple of years now,the Allison 6 speed auto.with tow haul and manual shifting ability,besides being almost bulletproof, put a fork in the manual tranny.


Is that what Peterbilt offers standard these days... I figured the low-end was still in the 435-470hp range. And you're right those trucks all make up 1850ft-lbs or more of torque, but still in 1990-8 if you had Peterbilt with a Cummins N14 435hp engine you had a pretty nice setup for the time and now you can get that hp in a pickup. That is insane if you think about.

Really, I think manual is the way to go myself. yeah I know the Allison 6spd is a great transmission and has double od gears ( I've read) but really nothing beats the experience of shifting a truck or car. It makes driving more fun.


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