SHORT TRIPPING WITH NEW 2025 6.7 EMISSIONS SYSTEM

[H3LZSN1P3R]

Maybe it’s more legal on a 5th gen HD

We need a cringe react lol.

 

[mbarber84]

Short tripping is harmful to more than just the emissions system. It should be avoided whenever possible. Especially in climates that routinely see very cold temperatures or significant temperature fluctuations.

 

[WXman]

I was thinking of helping my Son with a new Vehicle one day. I would LOVE to see him in a 2500 Crew Cab 6'4" bed 4X4 to keep himself and his family safe. They live in Canada right now and likely will be very cold weather at times and they don't tow or anything that I know of. I know that the average consesus is not excessive short tripping with the 6.7. But I am not sure that is a real issue like may say. I also am wondering if the new Emissions system will allow this without any issues. I am thinking yes?

Some of you have way more knowledge on this aspect of the Rams than I do. Thoughts?

Does it have to be a 6.7? You can get the same truck with a 6.4 which has zero emissions concerns or cold weather concerns, and will save $$$ everytime you turn the key to operate it.

 

[johnmyster]

You keep referencing payload as if its a legal limit when its not its for registration reasons the 2500 has 12040LBS axle weight rating thats what the weigh stations and police go by for weight restrictions not the “payload” sticker on the door

I don't think any authority who was looking into your setup would play the "sum of the axles" game, so the 12040 number becomes irrelevant. They'd consider each axle individually according to the lesser of axle or tire ratings.

My FAWR is 6,000, my RAWR is 7,000, my GVWR is 12,400...and my registration weight is 10,000. In my home state, this is the number that would attract the most attention. (I suspect out of state authorities would care less about the Virginia registered weight of a non-com vehicle.)

Short trips - I can't see how the drivetrain/emissions cares any more/less than a gasser, except on active regen day. Monitor for regens and stay rolling when they happen and I can't see any problem. My truck doesn't see sustained >600 F egt3 unless the camper is attached, so it isn't like it's getting passive regen under daily/short trip conditions. That said, I don't daily the truck and >40% of its miles are towing. Since I've been tracking it I only see 24 hr regens.

 

[TruckGuy98]

I don't think any authority who was looking into your setup would play the "sum of the axles" game, so the 12040 number becomes irrelevant. They'd consider each axle individually according to the lesser of axle or tire ratings.

My FAWR is 6,000, my RAWR is 7,000, my GVWR is 12,400...and my registration weight is 10,000. In my home state, this is the number that would attract the most attention. (I suspect out of state authorities would care less about the Virginia registered weight of a non-com vehicle.)

Short trips - I can't see how the drivetrain/emissions cares any more/less than a gasser, except on active regen day. Monitor for regens and stay rolling when they happen and I can't see any problem. My truck doesn't see sustained >600 F egt3 unless the camper is attached, so it isn't like it's getting passive regen under daily/short trip conditions. That said, I don't daily the truck and >40% of its miles are towing. Since I've been tracking it I only see 24 hr regens.

Does it show you on the dash when it’s performing a regen?

 

[AH64ID]

I don't think any authority who was looking into your setup would play the "sum of the axles" game, so the 12040 number becomes irrelevant. They'd consider each axle individually according to the lesser of axle or tire ratings.

My FAWR is 6,000, my RAWR is 7,000, my GVWR is 12,400...and my registration weight is 10,000. In my home state, this is the number that would attract the most attention. (I suspect out of state authorities would care less about the Virginia registered weight of a non-com vehicle.)

Definitely do some research before making assumptions.

I’m not aware of any entity that cares about GVWR for non-commercial use, even then it’s not about the weight but being registered. All that matters legally is axle ratings and registered weight. By registering your truck for 10K you have obligated yourself to the lower weight.

For example if you research GVWR in Idaho you’ll only find it in the glossary, it’s not a term that’s used for anything but insurance and some registration requirements. I’ve researched many states and have yet to find a location where GVWR means anything important.

Short trips - I can't see how the drivetrain/emissions cares any more/less than a gasser, except on active regen day. Monitor for regens and stay rolling when they happen and I can't see any problem. My truck doesn't see sustained >600 F egt3 unless the camper is attached, so it isn't like it's getting passive regen under daily/short trip conditions. That said, I don't daily the truck and >40% of its miles are towing. Since I've been tracking it I only see 24 hr regens.

Obtaining passive regen is only part of the problem with short tripping. The other part is the inherent inefficiencies associated with it, which is far worse on a slow to warmup diesel than a gas engine. Without getting everything up to operating temp each short drive is compounding potential issues. It takes 3-4 times as long to get a diesel engine fully warm than a gas engine.

You said it yourself, your truck isn’t getting passive regen on short trips. That’s not good for the after treatment. 13-18 diesels are far more forgiving to short trips than the 19-24’s thou, so it will be interesting to see how the 25’s do.

 

[johnmyster]

Definitely do some research before making assumptions.

I’m not aware of any entity that cares about GVWR for non-commercial use, even then it’s not about the weight but being registered. All that matters legally is axle ratings and registered weight. By registering your truck for 10K you have obligated yourself to the lower weight.

For example if you research GVWR in Idaho you’ll only find it in the glossary, it’s not a term that’s used for anything but insurance and some registration requirements. I’ve researched many states and have yet to find a location where GVWR means anything important.

Post #44 didn't stipulate non-com use, so that's a new facet to the discussion.

I'm not aware of any dangerous assumptions made. If I'm 500 pounds over on my back axle, any questioning authority doesn't really care that I'm 500 under on my front. DOT officers flag trucks for being over on steer axle on a regular basis. (Ask me how I know...I've had to repack a box truck before.) The "sum of axles" approach to GVWR 2.0 doesn't gain anything and doesn't hold water.

Under DOT requirements GCWR is taken as the sum of GVWRs (not GAWRs). So GVWR of the TV is used, at least indirectly, for regulations pertaining to combination vehicles. This is the only regulatory basis I can find for use of a GVWR, and as you've noted it's in commercial (DOT) space.

Federal Register :: Request Access

A finer point is that for the majority (all) of the MDT or HDTs that I've seen, the GVWR = sum (axle weight ratings). Thus, the axle ratings are more limiting and therefore, the target of enforcement. Before you exceed GVWR you'll exceed some axle(s). IMO this is why GVWR is ignored in DOT/commercial space. Yet, for personal/RV use, people trip over themselves to try to apply it...even for combination vehicles, despite a complete lack of statue, commercial or non-commercial.

I've done the research. In my state my pickup's 10k registration does indeed limit my legal/registered cargo carrying ability. Doing so avoids the costlier "by the pound" tags >10k. However, the heaviest use my truck sees is with a trailer attached, and trailers have their own tag/registration with an associated registered weight. For my state...by statute...for non-commercial use, as long as the combination is within the sum of the registered weights, I'm legal. YMMV, and perhaps you're under an authority where the RW of the TV must cover the combination.

Obtaining passive regen is only part of the problem with short tripping. The other part is the inherent inefficiencies associated with it, which is far worse on a slow to warmup diesel than a gas engine. Without getting everything up to operating temp each short drive is compounding potential issues. It takes 3-4 times as long to get a diesel engine fully warm than a gas engine.

Sounds like the case for a reduced OCI. Beyond this I'm not sure what the real worry is. People use vehicles how they use vehicles and then one day they trade it in. My truck isn't hurting itself any more as I leave the neighborhood on a cold start for a long trip any less than it is on a cold start for a short trip. The warmup cycle is the warmup cycle and you have to go through it regardless.

 

[johnmyster]

Does it show you on the dash when it’s performing a regen?

No but the idash does.

 

[AH64ID]

Post #44 didn't stipulate non-com use, so that's a new facet to the discussion.

This site is almost completely personal use, so it’s safe to assume personal unless otherwise stated.

I'm not aware of any dangerous assumptions made. If I'm 500 pounds over on my back axle, any questioning authority doesn't really care that I'm 500 under on my front. DOT officers flag trucks for being over on steer axle on a regular basis. (Ask me how I know...I've had to repack a box truck before.)

The axle weights are independent, I don’t think anyone said you can overload one axle if you underload the other.

Under DOT requirements GCWR is taken as the sum of GVWRs (not GAWRs). So GVWR of the TV is used, at least indirectly, for regulations pertaining to combination vehicles. This is the only regulatory basis I can find for use of a GVWR, and as you've noted it's in commercial (DOT) space.

Federal Register :: Request Access

A finer point is that for the majority of MDT or HDTs that I've seen, the GVWR = sum (axle weight ratings). Thus, the axle ratings are more limiting and therefore, the target of enforcement. Before you exceed GVWR you'll exceed some axle(s). IMO this is why GVWR is ignored in DOT space, and for personal/RV use, people trip over themselves to try to apply it.

You missed an important part in the definition of GCWR. If the GVW is higher than the GVWR then that value is used, basically what we can do with our Ram’s where FAWR+RAWR = more than GVWR.

“Gross combination weight rating (GCWR) is the greater of: (1) A value specified by the manufacturer of the power unit, if such value is displayed on the Federal Motor Vehicle Safety Standard (FMVSS) certification label required by the National Highway Traffic Safety Administration, or (2) The sum of the gross vehicle weight ratings (GVWRs) or the gross vehicle weights (GVWs) of the power unit and the towed unit(s), or any combination thereof, that produces the highest value. Exception: The GCWR of the power unit will not be used to define a commercial motor vehicle when the power unit is not towing another vehicle.”

I've done the research. In my state my pickup's 10k registration does indeed limit my legal/registered cargo carrying ability. Doing so avoids the costlier "by the pound" tags >10k. However, the heaviest use my truck sees is with a trailer attached, and trailers have their own tag/registration with an associated registered weight. For my state...by statute...for non-commercial use, as long as the combination is within the sum of the registered weights, I'm legal. YMMV, and perhaps you're under an authority where the RW of the TV must cover the combination.

In Idaho we don’t register trailers by their weight, it is covered by the trucks registration. The exception is RV’s which don’t count towards the vehicle weight.

Our weight brackets here are 0-8,000, 8,001-16,000, and 16,001-26,000. With the curb weight of a diesel pickup we shouldn’t even be able to register for 8K, but our DMV is a bunch of clowns and often don’t even ask people what they want for weight which leads to problems if you get pulled over towing. Even the Sprinter I just registered has a GVWR or 9,050 and the guy the wife talked to was rude about increased weight over 8K with the COO showing the GVWR right in front of him

 

[johnmyster]

You missed an important part in the definition of GCWR. If the GVW is higher than the GVWR then that value is used, basically what we can do with our Ram’s where FAWR+RAWR = more than GVWR.

“Gross combination weight rating (GCWR) is the greater of: (1) A value specified by the manufacturer of the power unit, if such value is displayed on the Federal Motor Vehicle Safety Standard (FMVSS) certification label required by the National Highway Traffic Safety Administration, or (2) The sum of the gross vehicle weight ratings (GVWRs) or the gross vehicle weights (GVWs) of the power unit and the towed unit(s), or any combination thereof, that produces the highest value. Exception: The GCWR of the power unit will not be used to define a commercial motor vehicle when the power unit is not towing another vehicle.”

I didn't miss it as much as it isn't relevant to this discussion.

What you're saying is that if you're over your ratings, your present weight becomes your rating. Ergo, you can never be over your ratings. That's not a valid reading of the text. Being overweight does not uprate your vehicle.

What they're actually saying is that even if your credentials (drivers license, med card, log book, and registration) cover the GVWR/GCWR of a vehicle, if your actual weights are over, you're in violation. For example, even if my GVWR is 8k, if I'm loaded to 12k and doing commercial things, I'd better have a med card and log book. Or, if I have a 26k gvwr box truck loaded to 28k and doing commercial things, I better have a class-b. Context is important.

What you're trying to say is that in the context of a combination vehicle, there is no legal/enforcement basis for the TV's GVWR. I would agree with this because the TV and towed vehicle's weight are now inseparable. So I agree, for combination vehicles, axle ratings govern and then in some funny way the sum of all GVWRs governs. GVWR for the TV (and thus, "payload") is now off the radar.

 

[AH64ID]

I didn't miss it as much as it isn't relevant to this discussion.

What you're saying is that if you're over your ratings, your actual rating becomes your rating. Ergo, you can never be over your ratings. That's not a valid reading of the text.

GVWR is a rating, not ratingS. Basically the GVWR isn’t all that important if other ratings allow you to be heavier, such as FAWR+RAWR. Which is exactly what the conversation is about, making it completely relevant.

What they're actually saying is that even if your credentials (drivers license, med card, log book, and registration) cover the GVWR/GCWR of a vehicle, if your actual weights are over, you're in violation. AKA, even if my GVWR is 8k, if I'm loaded to 12k, I'd better have a med card and log book. Context is important.

Yes you have to be legal to be at the weight you’re at, but regardless of how you look at it GVWR isn’t really relevant. Which is the entire point of the discussion, but not completely apples to apples with the commercial vs personal aspects.



The internet loves getting wrapped around the axle on GVWR, but it’s not nearly the big deal that is implied.

 

[H3LZSN1P3R]

I didn't miss it as much as it isn't relevant to this discussion.

What you're saying is that if you're over your ratings, your present weight becomes your rating. Ergo, you can never be over your ratings. That's not a valid reading of the text. Being overweight does not uprate your vehicle.

What they're actually saying is that even if your credentials (drivers license, med card, log book, and registration) cover the GVWR/GCWR of a vehicle, if your actual weights are over, you're in violation. For example, even if my GVWR is 8k, if I'm loaded to 12k and doing commercial things, I'd better have a med card and log book. Or, if I have a 26k gvwr box truck loaded to 28k and doing commercial things, I better have a class-b. Context is important.

What you're trying to say is that in the context of a combination vehicle, there is no legal/enforcement basis for the TV's GVWR. I would agree with this because the TV and towed vehicle's weight are now inseparable. So I agree, for combination vehicles, axle ratings govern and then in some funny way the sum of all GVWRs governs. GVWR for the TV (and thus, "payload") is now off the radar.

GVWR is only for registration not a weight restriction you can argue it till the cows come home but it does not change that fact.

 

[johnmyster]

GVWR is a rating, not ratingS. Basically the GVWR isn’t all that important if other ratings allow you to be heavier, such as FAWR+RAWR. Which is exactly what the conversation is about, making it completely relevant.

I agree, but only in the context of combination vehicles. Else, GVWR is meaningless...which it's not, regardless of enforcement standards in personal vs commercial use.

Second, your quote (I don't know where it comes from) made no mention of axle ratings. It never established that FAWR+RAWR = GVWR, which is the point of contention. So it's an argument about apples trying to teach us something about oranges. The quoted text establishes that GCWR = sum (GVWRs). In the context of combinations, summing axles may not allow you to be heavier if GCWR = sum (GVWRs) is more restrictive.

Again, I don't disagree in the context of combinations. GVWR/Payload of the TV does not have regulatory basis for combination vehicles because the combination is inseparable.

Our weight brackets here are 0-8,000, 8,001-16,000, and 16,001-26,000. With the curb weight of a diesel pickup we shouldn’t even be able to register for 8K...

That happens here too. DMV doesn't specifically know a vehicles curb weight based on options. So my listed EW for pickups has always been that of a stripped regular cab 4x2 gasser. They offer you the lowest applicable registration that would cover this errant EW and then it's up to you to upgrade.

 

[johnmyster]

GVWR is only for registration not a weight restriction you can argue it till the cows come home but it does not change that fact.

Rhetorical question then, so what is the point? Why not just set GVWR = sum (GAWRs)...like most MDT/HDTs?

It seems you're saying the point is that we can legally haul A but only register at B where A > B. Some ratings are made up ratings? Yet, SAE/FMSCA uses GVWR in the calculation of a regulatory GCWR implying that it actually does have substance.

SAE/FMSCA assign performance attributes to a a vehicle's GVWR. It would seem to carry interesting liability implications if one knowingly operates in excess of a manufacturer assigned performance parameter, even if enforcement typically focuses on other parameters.

It's cool. We can scoff at each other on multiple forums.

...GVWR isn’t really relevant...

I mean, I guess. Except when it is, in which case it is. Like if GVWR>10k, then your plumbing company should have door numbers and drivers should have med cards / log books. So it does have regulatory impact.

I've been there. With our last rig I was narrowly in on all axles, well in on tire ratings, in on GCWR (by FMSCA definition) yet over on GVWR of TV. If some lawyer wanted to apply DOT statute against me, I would've been fine because as I agree, GVWR of TV does not have basis in combination.

 

[H3LZSN1P3R]

Rhetorical question then, so what is the point? Why not just set GVWR = sum (GAWRs)...like most MDT/HDTs?

It seems you're saying the point is that we can legally haul A but only register at B where A > B. Some ratings are made up ratings? Yet, SAE/FMSCA uses GVWR in the calculation of a regulatory GCWR implying that it actually does have substance.

SAE/FMSCA assign performance attributes to a a vehicle's GVWR. It would seem to carry interesting liability implications if one knowingly operates in excess of a manufacturer assigned performance parameter, even if enforcement typically focuses on other parameters.

It's cool. We can scoff at each other on multiple forums.


I mean, I guess. Except when it is, in which case it is. Like if GVWR>10k, then your plumbing company should have door numbers and drivers should have med cards / log books. So it does have regulatory impact.

I've been there. With our last rig I was narrowly in on all axles, well in on tire ratings, in on GCWR (by FMSCA definition) yet over on GVWR of TV. If some lawyer wanted to apply DOT statute against me, I would've been fine because as I agree, GVWR of TV does not have basis in combination.

In the US in many states anything exceeding 10,000LBS gvwr (10,001+LBS) has to be registered commercial so this is the way they make it so people can own a HD truck and have it registered as personal use. Here in canada it’s different as we use 6500kg as the personal use registration limit before going commercial providing you have the OEM bed (not flat deck)

 

[johnmyster]

In the US in many states anything exceeding 10,000LBS gvwr (10,001+LBS) has to be registered commercial so this is the way they make it so people can own a HD truck and have it registered as personal use. Here in canada it’s different as we use 6500kg as the personal use registration limit before going commercial providing you have the OEM bed (not flat deck)

My case precisely disproves this.

My truck is GVWR 12,400, see signature. I registered it at 10k, as this is the highest "passenger car" plate offered, before stepping up to "truck" plates with much higher fees, higher property taxes, and a requirement for the plated weight to cover truck and trailer. (In theory I would need to plate at 20k, rather than 12,400.) So the discrepancy between axle ratings and GVWR doesn't actually impact registration in personal use space. 10k covers the listed empty weight so they did not scoff. Perhaps the rhetorical question has a different answer.

 

[HarryN]

Short tripping is harmful to more than just the emissions system. It should be avoided whenever possible. Especially in climates that routinely see very cold temperatures or significant temperature fluctuations.

In my mind, the answer to this is to have a fuel powered heater that can maintain the engine at some minimum temperature, so it will be less affected. Following the same approach as the larger diesel engine vehicles that "must work" / fire trucks. I kind of have to adopt this attitude, because the version that I want only comes in diesel, so it is a matter of figuring it out. Is a 6.4 liter gas engine so much more immune to cold weather than a diesel - maybe, but some personal Canadian friends with those hemis are not so sure.

 

[H3LZSN1P3R]

My case precisely disproves this.

My truck is GVWR 12,400, see signature. I registered it at 10k, as this is the highest "passenger car" plate offered, before stepping up to "truck" plates with much higher fees, higher property taxes, and a requirement for the plated weight to cover truck and trailer. (In theory I would need to plate at 20k, rather than 12,400.) So the discrepancy between axle ratings and GVWR doesn't actually impact registration in personal use space. 10k covers the listed empty weight so they did not scoff. Perhaps the rhetorical question has a different answer.

Perhaps in your state but there is more to the world than your state….im not sure but it sounds like nonsense why would the truck be plated for the towed vehicle I could see the pin weight but not the towed weight that would be retarded

 

[UglyViking]

My case precisely disproves this.

My truck is GVWR 12,400, see signature. I registered it at 10k, as this is the highest "passenger car" plate offered, before stepping up to "truck" plates with much higher fees, higher property taxes, and a requirement for the plated weight to cover truck and trailer. (In theory I would need to plate at 20k, rather than 12,400.) So the discrepancy between axle ratings and GVWR doesn't actually impact registration in personal use space. 10k covers the listed empty weight so they did not scoff. Perhaps the rhetorical question has a different answer.

What your local town registration agent allows, and what is actually legal in your state often don't align. A buddy of mine had a 3500 but didn't wanna pay the extra, so he went down to his town hall and registered it as a 10k truck. Agent said nothing, gave him his papers, and said have a nice day.

He then took his new paperwork for his 16k 5th-wheel down to his town hall, but again didn't wanna pay the insane fees so he de-rated it to a utility trailer or something. Again, town reg said nothing, let him do it for years and he never had issue.

Said buddy moves to a different town (same state) and tries to pull the same thing, town says "absolutely not" and he now has to pay the big boy fees.

Some states may allow you to register your vehicle at a lower limit, some agents may really just not have a clue. My understanding has always been that specifically for non-commercial, GVWR is basically a meaningless number. I've heard parroted so many times that if you were pulled over while using your truck + trailer in a non-commercial manner, you'd basically be free, but the worst case is they would weigh axles and check tires for weight ratings, same with trailer, and so long as you're under axle and tire weights, you're golden.

Obviously once you go commercial all the rules change. I don't have a CDL yet, so all the towing for my business has to be kept under that 16k number, which means I can only use my 2500 with my 14k trailer, because my dually puts me over and I'm operating for commerce. I also have to keep a log book for mileage after a certain distance from home, which I don't have to do as a non-commercial driver.

These debates have gone on forever, and I think there are a few reasons why.

1. Obvious distinction between commercial and non-commercial use that isn't always clear
2. States and even towns can have vastly different laws regarding reg and use
3. The fact of the matter is that non-commercial use is so rarely looked into that people get away with a lot
4. Some people are insanely risky (ie. loading way over GAWRs) while some people are insanely scared (ie. giving 30% or more headroom above GVWR)

I don't think anyone will convince anyone else of what is what with these discussions, especially considering how much patchwork of local and state laws there are.

 

[johnmyster]

What your local town registration agent allows, and what is actually legal in your state often don't align. A buddy of mine had a 3500 but didn't wanna pay the extra, so he went down to his town hall and registered it as a 10k truck. Agent said nothing, gave him his papers, and said have a nice day.

You're implying that what I've done isn't 100% legal, but it is. You license/register a vehicle for the weight class in which you intend to use it, which I have done. Maybe your state does not allow this, (but mine does) or maybe you've never bothered to question the registration class assigned to you by the DMV worker (but I have.) There is no regulation in my state stipulating the registered weight, but it's kinda obvious if it's less than book empty weight.

I mean, when I bought the truck the dealer registered it at EW 3500 pounds on a 5500 pound tag. I questioned him on it and he said that's what they do all the time. It's wrong but clearly the system allows for it. I hassled him to fix it and upgrade to the 10k passenger vehicle tag, which is the max my state has before going into "commercial truck" class.

Last company I worked for bought a tandem axle box truck. Door sticker said 56k GVWR. We never intended to use it that high saved a few dollars annually by registering it at 44k. CDL, DOT numbers, DOT inspections, sleeper cab, logbooks, everything, above board.

That said, other regulations DO depend on GVWR. For instance, my town "doesn't" allow street parking >7500 GVWR.

These debates have gone on forever, and I think there are a few reasons why.

1. Obvious distinction between commercial and non-commercial use that isn't always clear
2. States and even towns can have vastly different laws regarding reg and use
3. The fact of the matter is that non-commercial use is so rarely looked into that people get away with a lot
4. Some people are insanely risky (ie. loading way over GAWRs) while some people are insanely scared (ie. giving 30% or more headroom above GVWR)

I'd add:
5) In the absense of non-commercial regulation or enforcement, sometimes commercial guidance (regulation or enforcement) is the best things we have to go on. Clearly the rules don't apply in a strict regulatory sense, but if one ever needed to establish the difference between prudence and negligence, it would be hard to completely discount commercially accepted practice.
6) Some people blur the line between commercial and non commercial. "Personally owned" doesn't mean non commercial just because you're not a leased semi truck driver. That 7k gvwr half ton with a 3.5k gvwr landscaping trailer your yard boy drives falls over the 10k DOT threshold where DOT regulation may apply, depending on interstate/intrastate/excepted/distance from home. IIRC, 39 states require DOT/FMSCA registration/compliance for intrastate commerce. So even local commerce by plumbers/landscapers/land surveryor crews need to follow commercial rules.