Upgrading to a 6.7, but which?

[Synolimit]

My 2021 2500 6.4 lease is coming to an end with equity, figured it’s time to upgrade. My truck currently only has a 3,100 payload and 14,200 towing capacity. I going to start towing more with more cars and a bigger trailer.

Option 1. 2500 6.4 with the 4.10 rear

Option 2. 2500 6.7 with the 3.73 rear

Option 3. 3500 6.7 HO Aisin, 3.73 or 4.10 rear.

I see it’s h*t or miss on the 6.7 68RFE. I do like 35” tires!! And I’ll probably delete. I don’t want more power, just want the CELs turned off but I do understand the 68RFE can be tuned to run better. Just worried a delete will only try to add power and kill the 68RFE. I just don’t want any trouble with the EGR and filter etc. I’m also sad option 2 will kill my payload down to like 2,000lbs.

Anyone own these trucks and have a thought? Option 1 will have more payload than option 2 but option 2 will tow about 2,000lbs more. Will 35’s really kill option 2’s 68RFE? Or just screw it and be done by getting option 3 that’ll kill the others?

 

[crash68]

figure out how much your bigger trailer w/load will potentially going to weigh and size the truck from that.
If your working this for $$ and the potential load is pushing 20K lbs then only choice is a 3500 dually Cummins HO w/4.10. If the load is under about 18K the just the Cummins HO w/3.73.

 

[BossHogg]

I see it’s h*t or miss on the 6.7 68RFE. I do like 35” tires!! And I’ll probably delete. I don’t want more power, just want the CELs turned off but I do understand the 68RFE can be tuned to run better. Just worried a delete will only try to add power and kill the 68RFE. I just don’t want any trouble with the EGR and filter etc. I’m also sad option 2 will kill my payload down to like 2,000lbs.

Anyone own these trucks and have a thought? Option 1 will have more payload than option 2 but option 2 will tow about 2,000lbs more. Will 35’s really kill option 2’s 68RFE? Or just screw it and be done by getting option 3 that’ll kill the others?

If you want reliability leave the truck stock. If you are pulling under 20K pounds stay with the standard output Cummins. If the payload is a concern then go with the 3500. I tow a 16K fiver with a 2015 SO Cummins and not once did I ever say I need more power. What I do have is reliability.

But if you want to walk the expensive path of modification then visit the Cummins forums and look into after-market/reworked 68RFE transmissions. The Aisin transmission that comes with the Cummins HO isn't modifiable the last I read, no one has cracked the security of the transmission controller. Also, the HO Cummins is burdened with torque management so you would have to go the route of tuning and that is more difficult than ever with the EPA breathing down the backs of every tuning shop in the 50.

Then think about the drive line and 1,000 plus pounds of axle-twisting torque. I hope you have deep pockets.

 

[Choupique]

Reliability = stock. Deleting used to make sense on pre-DEF/SCR trucks. It no longer makes any sense. You won't gain much fuel economy if any, and you won't gain much engine life if any. Leave it stock. It ain't worth the money or the headache or the legal worries.

Same goes for the 68rfe. It's just fine if left stock and maintenanced on schedule.

Don't go buy a $65k+ truck and be worried about having to spend money and do crazy modifications make it reliable. If you feel that way, you should find something else to buy that doesn't give you those concerns.

 

[Synolimit]

figure out how much your bigger trailer w/load will potentially going to weigh and size the truck from that.
If your working this for $$ and the potential load is pushing 20K lbs then only choice is a 3500 dually Cummins HO w/4.10. If the load is under about 18K the just the Cummins HO w/3.73.

I understand what you’re saying but you didn’t address the tranny issues. In a perfect world the 6.4 with 4.10 would be best. 17,000lbs towing and cheaper gas. Maybe worse when towing but cheaper all around. But I don’t think anyone really wants to tow with a gas.

 

[Synolimit]

If you want reliability leave the truck stock. If you are pulling under 20K pounds stay with the standard output Cummins. If the payload is a concern then go with the 3500. I tow a 16K fiver with a 2015 SO Cummins and not once did I ever say I need more power. What I do have is reliability.

But if you want to walk the expensive path of modification then visit the Cummins forums and look into after-market/reworked 68RFE transmissions. The Aisin transmission that comes with the Cummins HO isn't modifiable the last I read, no one has cracked the security of the transmission controller. Also, the HO Cummins is burdened with torque management so you would have to go the route of tuning and that is more difficult than ever with the EPA breathing down the backs of every tuning shop in the 50.

Then think about the drive line and 1,000 plus pounds of axle-twisting torque. I hope you have deep pockets.

but we all know the EGR and filter are not reliable at all. I can't be away from home with a truck in limp mode with all the BS EPA stuff on. I have a better chance of not breaking down with a cleaner running motor. again I don't want to mod the tranny or add any HP that will break it. the tranny should run without issue whether the EPA stuff is there or not. I want to add my 35s on though.

yes I will be under 20k. but I see mechanics saying the 68RFE is good for only 12-15k reliable. that's pretty low on a 19,980 rating. I know it'll be under warranty but damn what a travesty if in limp mode or worse needing towed to the dealer because something in the system broke because of the EPA.

I did see those trannys, about 5-12k depending what you want to throw at it. I think the 5k is overkill if im leaving it stock (mines the delete).

 

[Synolimit]

Reliability = stock. Deleting used to make sense on pre-DEF/SCR trucks. It no longer makes any sense. You won't gain much fuel economy if any, and you won't gain much engine life if any. Leave it stock. It ain't worth the money or the headache or the legal worries.

Same goes for the 68rfe. It's just fine if left stock and maintenanced on schedule.

Don't go buy a $65k+ truck and be worried about having to spend money and do crazy modifications make it reliable. If you feel that way, you should find something else to buy that doesn't give you those concerns.

really? not trying to gain any MPG really but why wouldn't it gain engine life? if I don't gain engine life that's ok but why do I want to clean and replace EGR valves and the filter etc when it inevitably will break and go bad? a straight pipe can't break and turning the CELs off is just 1 less thing on a vehicle that's so computer controlled now a days.

hmmm I guess I only see the bad. at least I see on the 68RFE is to add a bigger pan and get rid of the thermo switch as it can clog up and overheat the clutch pack. best to make it run as cool as possible, or so I read.

I see what youre saying. an older truck without all the nannies would be WAY more reliable but I don't see great numbers from them for use.

 

[KKBB]

My take on this is to get a 3500 cummins HO or SO. Leave it stock. If you are getting rid of your 3 year old truck, I assume you will do the same with the new one. Why risk deleting it and getting in trouble with being caught, and also having no powertrain warranty left by doing a delete. If you are towing as much and as frequently as it sounds, you shouldn't have issues with the DPF. Just my opinion on this.

 

[Stavinksi]

if you’re leasing and trading at warranty expiration, why touch it? Beat on it, trade it in, repeat.

 

[mtnrider]

What are you towing with it (what does it weigh) that will determine the best option for you.

As far as the 68 is concerned, it's a good transmission (in stock form). It's #1 enemy is tuning and cranking up the HP (and driving like a teenager). They rarely fail stock and all the bad press you see are self inflected wounds.

,

 

[crash68]

I understand what you’re saying but you didn’t address the tranny issues. In a perfect world the 6.4 with 4.10 would be best. 17,000lbs towing and cheaper gas. Maybe worse when towing but cheaper all around. But I don’t think anyone really wants to tow with a gas.

If your at stock HP/Torque levels the transmissions should be fine.
If all driving is around your home of Ohio where it's mostly flat with 17K behind a 6.4 is probably fine. If your headed up and over mountains it would be a diesel or at least 4.30 gearing with the Hemi(especially if you upsize the tire diameter. Even then the Hemi will still suffer altitude power loss and doesn't have the exhaust braking like the Cummins.

 

[Choupique]

not trying to gain any MPG really but why wouldn't it gain engine life? if I don't gain engine life that's ok but why do I want to clean and replace EGR valves and the filter etc when it inevitably will break and go bad? a straight pipe can't break and turning the CELs off is just 1 less thing on a vehicle that's so computer controlled now a days.

Yes, really. Without spending too much time in the weeds, the modern engines run a very small fraction of EGR, and primarily use it to speed up warm-ups (a worthwhile thing) and to manage DEF consumption. It's practically a non-factor anymore. The Cummins of any vintage since about 2013 is going to drastically outlive the truck its mounted in.

You aren't giving those systems enough credit for how reliable they are. If you use the truck for what it was built to do (pull weight long distances) the odds are high you'll never see any problem. The whole drive train and aftertreatment arrangement in that truck has BILLIONS of miles of validation testing done on it. The tune that some jack leg delete shop dude worked up has very close to zero validation work done. Short term, sure it'll work without faults. Have they fully outfitted an engine with a complete suite of monitoring equipment (main bearing temp sensors, individual exhaust port temp sensors, cylinder pressure sensors, etc)? Absolutely not. They figured out how to get the truck to ignore the exhaust faults. Does that REALLY give you more comfort than operating a truck that had buildings full of engineers working for years and years and miles and miles of testing and validation?

Deleting for reliability or longevity does not make sense anymore. If those systems concern you, you should get a gasoline truck. I can tell you for sure that the concern is unfounded though.

 

[Choupique]

an older truck without all the nannies would be WAY more reliable

This is false as well. 100k miles on any modern vehicle, much less an HD diesel is practically nothing these days. In mechanical diesel engine days, getting 100k miles out of the thing at all was a major feat, much less to do it in 5 years like so many of us do now. Sure, the 180hp engine was probably still fine but the rest of the truck might not even have a body left on it by then. If you hook 20k lbs to a 1994 ford diesel and go try to drag it back and forth across the country a few times in August, I doubt you make it all the way across one time without something breaking.

Don't take it as an insult, but you should seriously consider a gasoline HD truck. You haven't even bought the diesel yet and in your mind it's already broken. You'll never really trust it and it'll be a massive money pit as you throw things at it to "fix" it and only make it worse. I've seen it happen to a dozen people in the past 5 years.

Just skip all that bull and get a gasser. It isn't worth the work or worry to be able to go up a hill a little bit faster.

 

[Tulecreeper]

This is false as well. 100k miles on any modern vehicle, much less an HD diesel is practically nothing these days. In mechanical diesel engine days, getting 100k miles out of the thing at all was a major feat, much less to do it in 5 years like so many of us do now. Sure, the 180hp engine was probably still fine but the rest of the truck might not even have a body left on it by then. If you hook 20k lbs to a 1994 ford diesel and go try to drag it back and forth across the country a few times in August, I doubt you make it all the way across one time without something breaking.

Don't take it as an insult, but you should seriously consider a gasoline HD truck. You haven't even bought the diesel yet and in your mind it's already broken. You'll never really trust it and it'll be a massive money pit as you throw things at it to "fix" it and only make it worse. I've seen it happen to a dozen people in the past 5 years.

Just skip all that bull and get a gasser. It isn't worth the work or worry to be able to go up a hill a little bit faster.

Agreed - the diesels are fine vehicles, but the gassers are way more convenient.

 

[jejb]

Agreed - the diesels are fine vehicles, but the gassers are way more convenient.

Umm, I don't think that's what he said.

I agree with what he actually said, that if you're buying a truck that your mind thinks is already broken, you should probably buy something else.

 

[Tulecreeper]

Umm, I don't think that's what he said.

I agree with what he actually said, that if you're buying a truck that your mind thinks is already broken, you should probably buy something else.

He said, "Just skip all that bull and get a gasser. It isn't worth the work or worry to be able to go up a hill a little bit faster." And I agreed. I think the diesels are fine, but gassers are the way to go. I'm sorry, I don't know how my phrasing was confusing. And you're one of the smarter people on here.

 

[jejb]

He said, "Just skip all that bull and get a gasser. It isn't worth the work or worry to be able to go up a hill a little bit faster." And I agreed. I think the diesels are fine, but gassers are the way to go. I'm sorry, I don't know how my phrasing was confusing. And you're one of the smarter people on here.

I think you are missing the context. He was not saying "gassers are way more convenient". He's saying that if the OP is that worried about the diesel being unreliable and having to stick a lot of money into it, a gasser would be the better option.

 

[Tulecreeper]

I think you are missing the context. He was not saying "gassers are way more convenient". He's saying that if the OP is that worried about the diesel being unreliable and having to stick a lot of money into it, a gasser would be the better option.

No sir, I was saying that. I was only agreeing with his point of view. I guess I shouldn't have mixed his statement with my opinion in the same sentence.

 

[Choupique]

Yall are basically both correct. If you're worried something will be unreliable, don't buy it. Especially not when it costs more than my first house did. If you think it's broken, than whether it really is or not you'll be worried about it and trying to fix it. Screw that. Get something that won't keep you up at night.

I have a diesel. Love it. I also do big diesel engine stuff for a living, fully understand all the ins and outs, and have more tools and information than most people do. It doesn't keep me up for 1 minute worrying about it. If it breaks I can fix it, including jury rigging it enough to get me out of a bind.

The majority of people driving diesel personal vehicles would be doing their bank accounts a big favor driving a gas HD truck, and I think OP is one of those people.

 

[Travelin Ram]

Any consideration of deleting means you’re not up to date. Ten years ago maybe, but not today.

And why would you blow up a 100k mile warranty on a brand new vehicle? That’s not good business sense.

And speaking of warranties, you should read the current thread about a 2500 with the warranty blacklisted for being overweight. Why would you consider a 2500 for heavy hauling at all? For a dedicated tow rig 3500 all the way.