28,500 lbs Ford vs Ram 1 ton DRW

Big Toe

You are getting mixed up with the "gross" and "net" power ratings terminology which is one of the reasons I why hate that it is stated that way. When people think of gross, they think that the engine is only being tested. While this used to be the case pre-emissions, this is not the case post emissions.

Instead of thinking of J1995 as "gross" power ratings. Think of it as an "as shipped" engine power rating which includes all devices that make it emissions legal. For example, if you go into Cummins Quickserve and input my 2014 2500s engine serial number, it will show all components that came with an "as shipped" engine to Ram.

You will notice below that the aftertreatment device is apart of the "as shipped" engine.



Then if you breakdown the aftertreatment device you will see what catalyst come with the engine.



I believe Cummins gets these aftertreatment devices from another supplier for the pickups, but I know they make them themselves for the larger engines, fire pumps, and gen sets.

So think of J1995 as an "as shipped" engine power rating rather than a "gross" power rating.

spoon059 wrote:

Grit dog wrote:
Some folks need more hobbies......

No kidding. Even for RV.net, this has gotten way off topic and out of control. Goodness gracious people...

Hope the both of you find a hobby you enjoy, as it might give you less time to criticize others enjoying theirs.


Shinerbock, thank you very much for continuing to take the time to help me understand what you are saying about Cummins engine testing.

Without asking you to be redundant, I'll have to admit I'm still struggling with how Cummins can certify a horsepower level to the EPA using a gross horsepower flywheel test standard (J1995)of the engine only with no appurtenant emissions equipment attached. I just don't understand how that would fly with the feds, so to speak.

It would certainly be understandable if non Californians didn't get why the horsepower number that a diesel engine manufacturer certifies to the EPA is important, and for towing RV's, it isn't important at all.

But when it comes to off road diesel equipment, such as tractors, back hoes, skid steers, skip loaders, graders, pavers, grinders, cranes, pile drivers, drill rigs, generators... an endless list of diesel powered industrial equipment needed to build and maintain the industry and infrastructure that enables folks to enjoy RVing and their yet to be found hobbies... that horsepower number has been extremely important ever since 2010, and will continue to be important, with significant financial impact, over the next 5 or 6 years.

I have to determine the manufacturer's horsepower rating for each piece of equipment in the fleet that I oversee, and add all of the horsepower numbers up. The cumulative amount of horsepower under operation is a significant determining factor in the compliance schedule and Tier level matriculation. The higher the cumulative horsepower under operation, the more significant the financial impact of forced retirement of lower Tier equipment. So it's a big deal to me. More than just a hobby.

I have to rely on the representations of the engine manufacturer, but quite often, I've run into conflicts where two horsepower ratings are provided for the same engine family number, or two engine family numbers are provided for the same engine... not in the books, but on labels permanently affixed to the engine. It is not my intent to drift too far into the weeds on my details, so bringing it back to the discussion at hand...

If an engine manufacturer uses a gross power measurement methodology to determine horsepower for purposes of marketing, and uses a net power measurement methodology for purposes of emissions certification, then I would want to be aware of it, because I would use the smaller of the two numbers in the fleet calculation of cumulative horsepower under operation.

But I do not see this with the on road Cummins diesel engine as fitted to the Ram 3500. There is only one horsepower rating per transmission and calibration submitted. Since that horsepower rating is certified with emissions, I'm still struggling to understand how a test methodology without emissions could be used.

This is why your post caught my eye, on an otherwise typical Ford vs Ram vs Chevy thread. Once you brought up certification standards, my interest perked up. The testing standard issue you raised is different than the dyno cert vs chassis cert discrepancy between chassis cabs (incomplete 450/550/650/750 and 4500/5500/6500) versus pickups (completed 250/350/450 and 2500/3500).

Thanks again for your comments. If you can think of any thing else to say or point a link to, without feeling redundant, I'd enjoy seeing or reading it. In the meantime, I'm still sort of stuck in the position where I began on this, albeit as always with an open mind.

Grit dog wrote:
Some folks need more hobbies......

No kidding. Even for RV.net, this has gotten way off topic and out of control. Goodness gracious people... its almost bad enough to make me log off and get back to work!

Some folks need more hobbies......

Big Toe

To further explain what I am talking about in regards to simulated conditions, take the QSM11 spec sheet in this LINK as an example. This is a standard spec sheet that Cummins will give to their customers (the vehicle manufacturers).

Notice at the top ,right below the emissions certification, where it states the simulated restrictions.

All data is based on the engine operating with fuel system, water pump, and 15 in H2O (3.733 kPa) inlet air restriction with 6 in (152mm) inner diameter, and with 2 in Hg (7 kPa) exhaust restriction with 5 in (127 mm) inner diameter; not included are alternator, fan, optional equipment and driven components. Coolant flows and heat rejection data based on coolants as 50% ethylene glycol/50% water. All data is subject to change without notice.


And at the very bottom it states the certification standards along with what elevations these power numbers are good for before electronic derate is applied.

Curves shown above represent gross engine performance capabilities obtained and corrected in accordance with SAE J1995 conditions of 29.61 in Hg (100 kPa) barometric pressure (300ft (91m) altitude) 77 deg F (25 deg C) inlet air temperature, and 0.30 in Hg (1kPa) water vapor pressure with No. 2 diesel fuel. The engine may be operated up to 12,000 ft (3,658 m) altitude before electronic derate is applied.

Huntindog wrote:

You keep saying it is only about the money...
Money is important, of course.

But if that were SAEs only motive, then why has the ford which is NOT certified, been spanked by GM over the years with a motor that IS certified with less power than the ford?

While I would say Ford has been "spanked by GM over the years" since it has been a back and fourth over the years depending on what testing you want to go by because there are many variables(like trans gearing, torque converter stall, drivetrain efficiency) besides engine power that can make each truck great at one test while crappy at another. there is also things such as programming to defuel or detune an engine to stay with in emissions or safe temps. Heck, there have been some Ike tests where the Duramax was bested by the Cummins that made less power.

But as I said only fan boys care about such things so they can pound their chest in forums like these. Most don't care as long as the truck pulls the load like they want or will add more power with aftermarket tuners regardless of brand.


However, you are moving away from our original debate which was the fact that J1995 and J1349 are certifications which you stated they weren't.

Kinda funny, Cummins knows exactly where every engine they build is going and they are tuned to the customers specs.

BigToe wrote:

Does Cummins identify, on any literature, website, or federally mandated document, that the 6.7L destined for pickups is certified per J1995, similar to how Cummins identified in the brochures of the two different M11s above as being certified per J1349?

In instances like the fire pump spec sheet that you posted where Cummins is the end product manufacturer, they use J1349. In instances where they only make the engine and not the end product, they use J1995. Again, J1349 is for manufacturers that design the end product, and J1995 is only for engine manufacturers that supply the engine.

The same goes for Cummins diesel generator sets where they make the end product. However, in some of their gas engine gen sets where they do not make the engine, those are J1995 certified by their engine supplier. It is not like they get a choice in the matter on which one they wish to go my, J1995 is for when you are an engine suppliers, J1349 is for when you produce the end product, and J2723 still uses either method but with an extra step of having a SAE witness. That is all.

BigToe wrote:
Is it possible that Cummins does use J1349,

Cummins does use J1349 when they are the manufacturer of the final product. However, in regards to the vehicle engine we are talking about, Cummins is NOT the manufacturer of the final product so they have to use J1995.

BigToe wrote:
Can we at least agree that SAE J1995 is commonly referred to as the test for gross horsepower without engine driven accessories, exhaust systems, or emissions control devices? And can we also agree that SAE J1349 is commonly referred to as the test for net horsepower, still measured at the flywheel, but inclusive of the induction, exhaust, and after treatment systems as the engine would be expected to be configured in use?

While J1995 is considered "net" power, this does not mean the engine manufacturer does not simulate or actually add these systems when testing. You can easily simulate the CFM of an intake or the back pressure of an exhaust with emissions in a test cell. They will sometimes denote this by saying the power ratings are "restricted" J1995 ratings meaning the restrict the power ratings to meet all emissions. They can even simulate other losses from things such as the fan clutch, alternator, and/or A/C compressor to even more load then they actually produce. You can even add these devices when testing like Cummins has done many times when certifying J1995 power rating. However, this is voluntary engine manufacturers under J1995, but is required for end product manufacturers using J1349.

Also there is nothing stopping Ram from certifying the Cummins in their trucks under J1349, but that is kind of pointless and most end users (besides fanboys of course) don't actually care about such things as log as it pulls the load.

I am not going to comment on the rest because I have a feeling I will just be repeating myself.

BigToe wrote:

On this particular engine it says to decrease the power rating by 3% for every 1000 ft of elevation gain above 300 feet above sea level. That is very significant. If the Powerstroke is similar it is more than enough reason to explain why it didn't climb the hill in 10 minutes. 3% for every thousand feet means a 450 hp engine at 300 ft above sea level becomes a 350 hp engine at 8300 ft above sea level. I wonder if both Powerstroke and Cummins are equally concerned about meeting emissions at 8000 ft elevation?

ShinerBock wrote:
"Cummins uses J1995 just like all engine manufactures that only make an engine and cannot control the intake and exhaust system of the vehicle the engine will be put in."

(Please see yellow arrows in photos below)







Does Cummins identify, on any literature, website, or federally mandated document, that the 6.7L destined for pickups is certified per J1995, similar to how Cummins identified in the brochures of the two different M11s above as being certified per J1349?

ShinerBock wrote:
"Even vehicle manufacturers test their engines the same way, but have to go by J1349 since they make the entire vehicle and not just the engine.

Ford makes their own engine, as well as the entire vehicle it goes in. Yet Ford doesn't "have to go by J1349". In fact, Ford refuses to altogether it appears, even while GM embraces a step toward common accountability and independent 3rd party auditing of the procedure and methodology used in the adherence to the standard. In fact, SAE suggests that following either procedure is voluntary, but in order to advertise "Certified to SAE J1349", a manufacturer must use the test procedure outlined in SAE J2723. No such requirement is made for advertising J1995.

Is it possible that Cummins does use J1349, like the older (predating the emergence of SAE J2723) Cummins brochures above indicate... but is prohibited from advertising it, because Cummins, like Ford, doesn't want to pay a third party independent verifier to monitor the testing procedure per SAE J2723?

ShinerBock wrote:
"The only reason why SAE came up with the new J2723 requiring a witness was so that they can get money from the manufacturers which in turn makes our vehicles a little more expensive

Perhaps at this point, we should see if we can at least find some common ground that we can agree on, so that I can make better progress in trying to make sense out of what you are suggesting, that you believe I am misinterpreting.

Can we at least agree that SAE J1995 is commonly referred to as the test for gross horsepower without engine driven accessories, exhaust systems, or emissions control devices? And can we also agree that SAE J1349 is commonly referred to as the test for net horsepower, still measured at the flywheel, but inclusive of the induction, exhaust, and after treatment systems as the engine would be expected to be configured in use?

And can we at least agree than neither J1995 nor J1349 take into consideration drivetrain losses? And, unlike some common misconceptions out there on the net, we both can agree than neither J1995 nor J1349 refer to any measurement of horsepower at the wheels, where the rubber meets the road or the dyno rollers?

If we can agree on all that, then can we take another look at that 2017 Ram Cummins 3500HD that is the subject of the video in the original post briefly? I have not seen that video, nor am I the least bit interested in, but I do remain very interested in trying to understand and reconcile what I may or may not have misunderstood you to be suggesting, compared to what I read in the Cummins application to the EPA and CARB for this 6.7L engine, where a horsepower rating, induction system, and exhaust system all must be certified in an "in use" configuration.

Here is the cover letter Cummins sent to the EPA...






I underlined "in use", because that is a critical term in emissions parlance. In use is not gross power of the engine in a vacuum, without regard for induction and exhaust and after treatment. In use is as the engine will be configured for use on the highway, which is what the EPA is concerned about.

So let's look at the alphabet soup that the engine is surrounded by in use:




That will take a moment or two to read. It no doubt took a lot longer to test... but Cummins tested and certified it. Cummins applied for the approval. Cummins will be the VW paying the fines if Cummins got it wrong. This is why the idea that Cummins would certify to the EPA the gross HP level of the motor, while simultaneously certifying that that Gross HP number applies with all the induction, exhaust, and aftertreatment systems included... doesn't make sense to me.

It seems more likely that Cummins would follow the SAE J1349 standard, as Cummins own literature suggests that they are given to do, for the purpose of accurately determining a HP level to a Federal agency that has the power to stop the sale of their vehicles, force a recall and retrofit of their vehicles, and levy a fine of up to $10,000 per vehicle per day, if the certified numbers don't match up with what can be independently verified.

Here are the horsepower levels Cummins submitted with their certification:








Speaking of liability, I can easily see why Cummins wouldn't advertise that they use J1349 to determine net horsepower, since they could then be sued by the SAE, since the SAE owns the rights to the standards. Because of 50 years of bogus claims by vehicle manufacturers in marketing materials, the SAE has had to continue to close the loop holes that manufacturers have found to circumvent the fundamental idea behind a standard. Which is to create a standard. A foundation for fair comparison.

Apparently, manufacturers cannot be trusted to watch the hens without spiriting off with a few eggs, so J2723, requiring an independent witness to verify the manufacturer's adherence to the test procedures outlined in J1349, was developed to re level the playing field once again, with stricter oversight. The cost of that oversight is borne by the manufacturer, who will of course pass it on to the consumer. But to claim adherence to J1349, the witness must be paid to watch.

Otherwise, no advertising J1349. However, that doesn't automatically mean that Cummins is going to report to the EPA some HP numbers that are determined separately from the induction, exhaust, and after treatment systems included in the same certification.