Put away your tin foil hat; it has nothing to do with the government. Medium duty trucks are almost always derated for longevity. You think all those 26-foot box trucks with 7 to 9 liter diesels being driven by 20-year-olds without CDLs are rocking 500 horsepower? No. Barely 300, most of them. Manufacturers know that these vehicles are going to be at or near their GCWR and the guys driving them are going to stand on the pedal because it's someone else's truck. So to keep the Duramax from turning itself into kibbles and bits they derate it to 350 or so HP and call it the L5D instead of L5P. Ford does the same thing with their cab/chassis versions of the super duty and I assume Ram does as well.

 

I didn't ask what was and was not a reason they come with lower ratings. I asked what the difference was between the two was in order to uprate MINE! I HAVE a CDL and my drivers run several 550 HP / 2050 Torque rated Cummins Engines in my fleet.

 

I appreciate you taking time to slam an insult in your reply. Matter of fact if you need to go there when posting your OPINION NOT FACT BASED statements just pass me by please. In fact, that goes for all you would be keyboard warriors!

 

Which statement of mine contained an opinion? True or not, I'm pretty sure everything I said can be objectively confirmed or denied. I.e., none of what I said relates to matters of opinion.

And maybe try dialing back your sensitivity a bit. You made a silly (and false) reference to government regulation and I poked you a bit, but at least I answered your question. And the reason my post has so many "likes" (by folks with CDLs and engineering degrees, among other credentials) is because it contains the correct answer.

 

Dude, you acuse him of being a keyboard warrior, really? That was mild.

One day vacation for you due to the use of profanity. Take a breath, cool off.

I'll be editing your post as well to remove the profanity.

 

I know it's nearly irrelevant on a GM site but I can confirm the 3500 chassis cab Ram CTD engine is derated vs a normal 2500/3500 pickup. It's power levels are 360/800 vs the normal 370/850. I would bet without looking the class 4 & 5 trucks use the same engine as the 3500 C/C. I always figured it was just a tuning thing until I recently saw a parts comparison of the engines and found that the derated engine has at least a different camshaft, maybe more. So there goes the theory of someday reaching normal power levels via a simple reflash.

Curious now if the GM engines are similar. Maybe the detuned engine is more than just a tuning thing on them too?

 

I even watched a video on YouTube from a GM dealership for the derating at one point. I'll try to find it. They explained it well.

 

The MD trucks use a different turbo and ECM. To be honest, I can hardly tell the difference between the '19 3500 CC 4wd and the 4500 probably due to the 4:30 gearset. So it has only 350HP and 700 # torque. Pulls everything I hook to just fine.
AND, I agree that it was derated for a long life and able to withstand abuse as JD stated.
Unless you're running a big semi with a real load I can't see why you would need 500+ HP in a MD truck.
P.S. its not the hp that does the work its the gears and torque

 

Here's the video I watched, they talk about the derating. Yes, a lot of other details as well...

 

Well, it appears you are unable to post without a demeaning remark attached. I guess you just have an inferiority complex you need to compensate for.

 

Ok, enough. Let's all move on with life.

Anymore personal comments and the thread gets shut.

Take a look a what we posted above, especially the video.

I get the impression that the ratings are what are at the wheels too, so you have to account for drivetrain losses.

 

Business Question - Torque pulls the load, HP gets to speed faster, the higher the horse the more fuel burn needed, Unless your truck/fleet, economically why would you want to increase the engine power thus increasing more fuel burn? The drivers will still most likely put there foot to the floor, the truck will just be stressed more leading to immature repair expenses and fuel/def expense will increase which is a loss to the bottom line?

 

I guess I was typing my why at the same time you were typing this question. See above.

 

Yes, agreed, enough of the bullying and negativity from those who live to type on this site.

I owned a 2005 Duramax 4x4 and sold it 8 years ago with 360,000 miles on the clock. During that ownership, I tried the tuners and hated the hard shifting they presented so I went back to stock for the longevity side. I replaced that 2005 2500HD with a 2013 2500HD 4x4 Duramax and now have 335,000 miles on it. Due to the increases in torque and HP, with better MPG, I never even THOUGHT about needing more power for the 2013. Now I am looking at owning a 5500 4x4 Duramax with air ride rear suspension under a camper so I am wanting to get the STOCK 2500/3500 Duramax torque and HP ratings. I carry a lot of weight, I tow a lot of weight. That is the reason for asking here for information on what the difference between the pick up and the MD truck engine is. I am not going to use it in a work environment with teenaged drivers so the reasoning of longevity does not apply so much to my application. I know how to drive with more power than is needed when it is not needed. I am not looking for horsepower to light the tires up at stop lights. I am looking for improved acceleration when forced to slow down on a long grade and for quicker zero to 60 for on ramp safety/ease of entering traffic flow. I am also looking for increased uphill speed sustainability on a long grade so that is why the want for more torque.

The video was interesting but for me lacking in information to my question. I will keep searching for the actual answers. EPA and CARB play a role in power and emissions for commercial vehicles and the downrating is a part the detune. I understand this.

My question still stands. What is the actual difference, mechanically and or tuning wise for the Chevy pick up vs the Chevy MD with Duramax power and Allision Transmission?

If it is a turbo and tuning then the fix is quick and easy. If we are talking valve train or pistons or crank, then it will be out of the question for me.

 

And while I am asking WHY? WHY oh why must Chevy put the DEF tank on the passenger side rather than the drivers side when all the DEF pumps are on the driver side in the truck stops. SUCH a pain to get DEF in on the passenger side!. Now, I know they say they put if on the opposite side so there is no confusion, but the DEF NEEDS to be on the drivers side!!! What a BIG mistake IMO to put it on the passenger side!

 

The tank is on the pax side. They save $15 on hose alone.

 

No one ever said you had to have common sense to be an engineer!

 

Personally, I like the def on the right. Never heard of someone putting diesel in the def tank or vice-versa until GM put them both on the same side. On the MD it is right out in the open.
Better check on the air ride for your truck- when I got mine , 4x4 got everybody a 7500# front axle but no air ride with 4x4 available.
Also, these trucks are speed limited based on what gearset you have.
I don't think GM has ever published the exact differences between the L5P and the L5D beyond the turbo and ECM. It MIGHT has some internal changes as well.

 

Personally, I like the def on the right. Never heard of someone putting diesel in the def tank or vice-versa until GM put them both on the same side. On the MD it is right out in the open.
Better check on the air ride for your truck- when I got mine , 4x4 got everybody a 7500# front axle but no air ride with 4x4 available.
Also, these trucks are speed limited based on what gearset you have.
I don't think GM has ever published the exact differences between the L5P and the L5D beyond the turbo and ECM. It MIGHT has some internal changes as well.

I am curious since you like the DEF on the right, what is your reasoning for that? I use truck stops to fuel up and it is a PAIN to reach the hose to the passenger side for me.

 

There were plenty of early fords and canyons that got a taste of def in their tank. Some more than a taste.

 

I have no doubt that could have occurred. BUT, IMO, no reason for penalizing the masses with inconvenience. Maybe most people use the non environmentally friendly jugs from the convenience markets...

 

 

https://gmauthority.com/blog/gm/gm-engines/l5d/

Here's another forum you could join with some info.

L5P: - L5D convert to L5P?

So how hard is it going to be to make an l5d in the new medium duty produce the same power as an l5p? I assume the turbos will need swapped and a tune. Would one be able to flash a tune from say, a 3500 regular truck onto a 45/55/6500 computer?

www.dieselplace.com

The complication you will have is dealing with a tune and a locked ecm. I wonder if a conversation with Banks and trying a couple less expensive less evasive products like the peddle monster and or derringer would not be a great place to start.

Made for some fun research. Seem the only engine difference is the undersized turbo which must be replaced before trying to increase hp/torque, engine tuning and of course the rest of the drive train.

Personally if I was wanting to throw money at it I'd start with a conversation with Banks.

 

View attachment 1114126

https://gmauthority.com/blog/gm/gm-engines/l5d/

Here's another forum you could join with some info.

L5P: - L5D convert to L5P?

So how hard is it going to be to make an l5d in the new medium duty produce the same power as an l5p? I assume the turbos will need swapped and a tune. Would one be able to flash a tune from say, a 3500 regular truck onto a 45/55/6500 computer?

www.dieselplace.com

The complication you will have is dealing with a tune and a locked ecm. I wonder if a conversation with Banks and trying a couple less expensive less evasive products like the peddle monster and or derringer would not be a great place to start.

Made for some fun research. Seem the only engine difference is the undersized turbo which must be replaced before trying to increase hp/torque, engine tuning and of course the rest of the drive train.

Personally if I was wanting to throw money at it I'd start with a conversation with Banks.

GOOD POST!
I have the full shebang banks turbo kit on my 2005 Jeep Wrangler LJ. They do good work there!

 

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DEF separate from the Diesel filler is a good idea, besides many people fill up the DEF while pumping diesel. You can't do that when they are co-located. Again like Mikey52 noted gM probably save some bucks on the hose. LOL

 

Well, I guess this means truck drivers are smarter than pick up owners...since the DEF is on the driver's side along with a fuel filler neck......OUCH!