5.9 vs 6.7 3rd Gen Cummins | Which Is Best and Why

I'm Andrew and I'm setting out to make better videos for diesel enthusiasts follow along as I review products twos and share my personal trucks here on just diesels what's up guys and welcome back today we're going to be doing another comparison video and more specifically we're going to be looking at third gen trucks now if you've been shopping for these you might have noticed that there are two different engines available in the late model third gen trucks that's going to be 07209 trucks and they're going to see that there is the five non Cummins in the 06 and erlio7 trucks and then in the lato 7209 trucks you're gonna see there's the 6.7 liter Cummins what's the difference which one's better today we're going to answer that question and I'm going to do that for my personal experience this is not a YouTube video where I'm just stealing people's footage and talking about it from not having experience I actually own a five nine truck I have a lot of experience with the six seven trucks like the one behind me and today we're going to be putting that to the test I'm gonna be sharing with you guys which one is best for what end person so to keep things organized we're going to be starting with the general truck what's different between the two trucks we're gonna be talking about the engine what's different between the two engines next we're going to go into the emission system and then finally we're going to talk about the transmission and then kind of who's the right person for which truck so to start out with truck wise these trucks are actually almost completely identical so in 2006 Ram updated the third gen platform to get the big headlight exterior it's a little more modern than the early 03 to o5 trucks and then you're also going to see some changes on the interior this is kind of the big reason a lot of people prefer the late third gen trucks that's why I have an o6 truck it's because Ram updated the interior you're going to get a much more modern feeling interior a little bit more room a little more Comfort a little more amenities it just it feels a little more modern the early 03.05 trucks kind of feel in this weird spot where they're not quite old enough to be the second gen where they're nostalgic they're just kind of outdated on the interior so generally the 06 plus trucks are preferred they have a little bit higher quality Plastics in them just things are a little bit nicer overall in the interior it's a little bit just kind of better truck aside from that visually the trucks are identical suspension wise they're identical they are identical in terms of the outside appearance everything from 06 to 09 is going to look the same the one key differentiating thing is the tail lights in 2007 Ram went to kind of like these two dual bubbles on the rear tail lights so if your shop thing a really quick way to tell 06 from 07 to 09 or a truck that might have a six seven is going to be the tail lights 06 trucks are going to have a smooth tail light 07 plus is going to have the bubble tail lights and 07 was a split year so for half the year they did five nine half the year they did six seven so you know it's a little overlap but generally as a rule of thumb if you see the bubble lights there's a solid chance the trucks at six seven just because there's more of them out there so now let's dig into the engine this is where things are very different obviously you're going to have the five nine and the 06 to early 07 trucks and the six seven in the 07209 trucks and what's different between those two engines in terms of on paper stats you're going to be seeing 325 horsepower out of the five nine 350 out of the 6.7 you're going to see 610 foot-pounds of torque out of the five nine and 650 out of the 6.7 they both are controlled by the CP3 injection pump from Bosch a super reliable pump but you're gonna see key differences in the injection system as well so the six seven system is going to be a little bit more robust little bit more reliable it actually flows more fuel than the 5.9 injection system in terms of the Rails the injectors and all that stuff the other key difference in the engine is the turbo on the 6.7 you get a vgt turbo or variable geometry turbo where the veins the turbo actually change position now this is really cool because you're able to build more power at lower RPM and sustain that power and higher RPM because the turbo can kind of pretend it's a different turbo on the five nine trucks you have a fixed geometry but that turbo vanes are just in one position and that means you have a little bit less low and a little bit less high end out of that same turbo now the other thing you're going to get in the 67 is going to work in conjunction with that turbo is you're actually going to get a higher compression ratio and a longer piston stroke so you're able to actually build more power at lower RPMs you're going to see the six seven trucks are actually going to be a little bit quicker off the line a little more low end Grunt and this is awesome for towing combine that with the vgt exhaust brake that you get out of the variable geometry turbo on the six seven trucks and you actually make for a very good Towing platform so right now everything is pointed thing on paper to the 6.7 liter being a better engine it's essentially a more beefed up version of the five nine so why would anyone choose a five nine when the six seven is on the table well it's emissions and that's the next topic so in 2007 the EPA introduced the Next Generation admissions requirements for diesel pickup trucks that meant that all manufacturers had to have EGR on the engine and they had to have DPF or diesel particulate filters on the exhaust system this was the first time that any of this stuff is introduced and so over time it has definitely proven to be a little bit less than reliable there were also some big hits to fuel economy that came along with that in stock form I wouldn't say a 5.9 gets double the fuel economy of a six seven but it's close it is is a legitimate change from driving my buddy's truck on long road trips it's interesting because you will be getting really solid fuel economy and all of a sudden the regen kicks in and you're dropped into single digits and you can recover from that when you're not regening but you have this really big variance and so it ends up significantly dropping the field economy overall the other thing of course is that with the EGR or exhaust gastro circulation system you are physically pumping old exhaust gas back into the engine at each combustion stroke on the five nine the late six seven trucks the introduce what's called in cylinder EGR was controlled by the cam it's very minor I would say it's a pretty much non-issue on the six seven trucks there's actually a valve that is diverting exhaust gas back into the engine now that's going to make it a little bit less efficient but it's also going to be putting soot straight back into the engine so you're going to see a lot dirtier oil you're also going to see issues with the valves clogging up with soot you're going to see issue with the EGR clogging episode the EGR cooler clogging episode just a lot more stuff going on a lot more issues that can happen and a lot more maintenance that's going to happen down the road now in the exhaust system the five nine trucks only had a cat it was just a dummy cat there was no sensors plugged into it or anything I still have one on my truck so I can pass smog in California because it really doesn't hurt anything performance wise on the six seven trucks this is where you had to have a cat and a diesel per ticket filter a DPF now DPF is basically just a giant filter that catches soot coming through the exhaust and then by releasing fuel on the exhaust stroke you then burn that fuel out or burn that soot out but of course you're releasing more fuel you're burning more fuel and that whole system just is kind of issue prone this was the first time that they had done this on big diesel pickup trucks and it just hasn't proved to be very reliable so if you're looking at a six seven truck there's a pretty high chance that the DPF has been replaced or will need to be replaced unless you were towing with these trucks heavily that's kind of the only time where I see them be super reliable outside of that if the people are just daily driving the truck and stuff you're going to have issues with the EGR and the DPF there's no way around it it's a very early version of the submission system and it definitely had its issues surrounding it now of course there's the whole topic of modifications and aftermarket modifications so if I wanted to make power on my third gen all I would have to do is slap a tune on it I'm going to round 500 horsepower no big deal same thing with the six seven except that you have to remove the emission system as well if you actually want to make big reliable power on these trucks you have to remove the EGR you have to remove the DPF and then of course that comes with one an extra price tag you're looking at you know 2500 three grand to get that done and two you are now a 50 state illegal truck it is a federal crime to remove the emission systems on these trucks so whether your state checks or not still a federal client so in my situation I thought the 5.9 was a better fit because I didn't have to mess with that I live in California I can still pass smog every two years with no hassle on my truck I still have the cat in place I have a five inch turbo back exhaust I've got EFI live tuning that I just pull off every two years for the smog check and I'm good to go if I had a six seven at the truck behind me I couldn't pass smog I couldn't have this truck in California unless I went through all kinds of backdoors it's just it's not worth it to me so that is one thing to consider is that even though the six seven is better on paper there's a lot of extra costs that go along with that and that leads me into the next topic of this which is the transmission now on the topic of Transmissions let's say you were looking for a manual truck for the 06 to 09 range trucks the manual that was available is going to be the G56 that's a six-speed manual and that's exactly what is in my 2006 truck this is a super desirable transmission a fantastic overall setup and it's going to be pretty dang reliable on both trucks so if you're looking at manuals the Transmissions are it's actually going to be completely equal this trans will happily take around 500 horsepower with an upgraded clutch anything past that you're currently going to be looking at building transmission but it'll actually take some pretty solid power numbers for a pretty long time without braking so this is actually a really cool manual transmission and it's why I selected it in mine and this is available in both trucks so if you're comparing manual to manual the big thing is actually going to be the engine and the emission system surrounding it as the key difference between them so the five down trucks are going to have the 48re transmission that's a four-speed transmission this is going to be kind of the relative of what was on the second gen trucks I'm not gonna lie it does hold up okay in stock form but it's definitely not a fantastic transmission um one it's only four gears so on a diesel the more gears you have the better because it keeps the truck in its power band it's a very narrow Power Band than a diesel so the more gears the better and a four-speed isn't quite cutting it that said they're pretty easy to build and they hold a stupid amount of power when they are built if you are going to be doing a built 48 or 47 transmission you're only looking at somewhere between like four to six grand for a very reasonable build that will hold 500-ish horsepower on the six seven you have the 68 rfe transmission now this is a six-speed transmission uh which actually from the drivers of the truck drives a lot better it has a lot more positive torque converter lockup it puts the power down a lot better than the 48 in stock form and it's also going to have more gears the truck's just going to be a little bit more efficient in its General Power Band it actually is meant OK Transmission in stock form the problem is you throw extra power at it and it also will die just like the 48 neither one of them really is very reliable with extra power the cash on 68 is it's a lot more complicated during the mission and so it's a lot more complex and expensive to build if you are going to be building a 68 you are looking at somewhere between eight to maybe 11 grand for that same level of build to hold five 600 horsepower so it's a huge jump up so if you're looking at these true trucks and you are trying to make them reliable and just have a general bump in power uh it's gonna be a lot more senses on six seven you have to delete the truck which is like three grand plus you're looking at an extra three grand or so in the transmission so it's like six thousand dollars more to get to the same level of reliability and power that you got out of the five nine so that gets into the final topic of this and that is which truck is right for which person if you or someone like me that's looking to either keep the truck stock or do a very basic power bill just you know making like 400 horsepower something like that nothing crazy I think that the five nine trucks are a better option um I think that they are simpler you can do everything cheaper and while the initial purchase price of the truck might be a little bit higher because it's only a year and a half span of the big headlight five nine trucks I think it ends up evening out because you just have less hassle down the road you don't have to worry about being federally illegal on your emissions you don't have to worry about the extra added Hassle and cost of deleting the truck the transmission build is cheaper the six seven of course also has its place because if you're looking to do big Power the six seven is basically a more beefed up version of the five nine so let's say you're looking to build a full drag a full race truck that's making a thousand horsepower the six seven is gonna be a much better starting block you're getting a much more robust fuel system or more robust block a larger displacement so you're actually able to spool larger turbos easier because of that bigger displacement and so in that situation the 67 is a way better truck you're able to get the same overall build of the truck but you're able to make a lot more power out of the engine in those big numbers with kind of more reliability that said I think the general consumer isn't doing that most people aren't doing crazy full-on engine builds with forged rods and everything else most people are just looking for a reliable tow rig that can pull their trailer that can have a little bit of bump over power and just be a reliable solid diesel truck and that's where the five nines I think take the win so in terms of deciding what truck is right for what person it really comes down to your use case if you are someone that doesn't mind removing missions equipment and doesn't need to test the truck let's say it's off-road only a race truck or let's say you just live in an automations place the six seven actually does make a good argument if you are going for that truck and you don't mind the added cost of building the transmission and the emissions removal it's a solid truck you're going to make more power out of it it's going to make more power at lower RPM basically everything's going to be better I think actually the injection system injectors themselves are a little more reliable than the five nine trucks that said if you're like me where you live in California you live in a place that has emissions and you just don't really want to mess with having a federally illegal truck the five nines are where it's at and that's why the command's such a premium in the used Market because they only existed for a year and a half in this updated body style so you're basically going for the Holy Grail of third gen's uh you know if you want to use that term for it so hopefully that helps you guys decide between these two trucks I personally thought that the 0659 is the way to go for me but everyone has their opinion so feel free to comment your opinion down below hope this video helped you guys decide if you are shopping for one of these trucks and if you like this video please subscribe to the channel got a lot more stuff like it so thank you so much

Channel: Just Diesels

Views: 226,925

Keywords: cummins, powerstroke, diesel, dodge ram, ram, dodge, carli suspension, carli, lift, lifted, lifted truck, 5.9 cummins, Ram, Dodge, Ford, 7.3 powerstroke, f-25-, f-350, 2500, 3500, trucks, lifted trucks, diesel trucks, diesel truck

Id: XIo05Fzzj-I

Length: 13min 21sec (801 seconds)

Published: Fri Jun 02 2023