12v vs 24v truck

[Heavyd1980]

Ok guys so far I have seen truck after truck (12v) get better mileage than a 24v so what else is there to consider when looking to buy a cummins powered truck??? Lets see what everyones opinion is on this subject since I could have used some of this info when I was looking. Thanks.

[dorkweed]

The 12V trucks get better mileage mainly because of the higher compression ratio and the lack of pollution ____ in the exhaust system!!!! The 12 valvers were the original "torque monsters" as far as light truck towing goes. Heck, 460ft.lbs. right off idle........ain't no gasser gonna do that!!!In order to be more "car like" and "environment friendly", the Cummins engineers (due to EPA regulations) have been decreasing the compression ratio, adding valves, increasing boost, retarding timing, adding multiple injection events, adding exhaust crap, etc. over the last 20 years to make our "TRUCKS" drive more carlike and to theoretically decrease pollution!!! I won't go into specifics here.........but the 24 valve Cummins are capable of great mileage when driven so and with the right mods. If I drive my 04.5 with the mods in my signature at 65mph I can honestly say that I'll get between 19 and 22 mpg.....................the most dependent factors being temperature and wind direction!!! That's empty driving.............no load in the truck and no trailer towing.Cruising the various websites, the guys that _____ and moan about mileage the most are the ones that almost always say that if I drive 65mph on the Interstate, I'll get my doors blown off!!!! In all honesty, I don't care if they pass me doing 200mph on the Interstate.............for me, to drive faster than 65mph on the interstate, in traffic, weaving in and out, is "HUGELY STRESSFUL". I find myself more at ease letting everyone pass me...........rather than worry about me passing the butthead in front of me while I've got some ******* on my trailer hitch trying to pass me!!!!!! That's why I get good/great mileage on my 04.5 Common Rail Cummins.................because I don't give a rats ___ about anyones opinion that I drive "too slow"!!!!!Rant off!!!

[ISX]

Alright I will settle this once and for all with the pros and cons of each and you can decide for yourself. They excel in different areas so it's not always the easiest thing to just say "one is better". I am also only listing REAL differences. Like I don't see the point of 12 more valves, I have seen no proof of it having any benefit for the common guy wanting <400HP. Therefore, I am not listing it. Or anything else I have seen no benefit or degradation from. Timing barely made it to the list.

24V VP44

Pros

[*]Dynamic Timing

[*]Can monitor many things with scan gauge

[*]Manuals have auto compensating throttle (let off clutch and rpm goes down, 24V holds it up..kinda nice)

[*]Can put a chip/programmer, whatever, on it and change settings on the fly

[*]Error code problem diagnosis (most of the time anyways)

[*]Computerized idle (always 750 or whatever stock was, never changes)

[*]high idle

Cons

[*]Electric lift pump goes out (have to get airdog or something to fix it permanently)

[*]VP44 goes out (2 stroke seems to keep it happy, but not 100% chance it wont fail again..)

[*]Fly by wire pedal, always have to reset it or buy a new one or...junk

[*]Has an ECM, which goes out some times

12V P7100

Pros

[*]P7100 never goes out

[*]Lift pump only goes out if you use terrible fuel, and even then will last 200k miles

[*]Everything can be manually set if your into that sorta thing

[*]Does not rely on a computer

[*]Can be started without any kind of electricity (push start it, push fuel solenoid up)

Cons

[*]Static Timing

[*]Cannot easily revert changes in fueling (grind plate, now your screwed if you want it back stock)

[*]No set idle so the cold will make it idle low, to the point of stalling if your idle is set too low

[*]No clutch auto compensation fueling

[*]No high idle function (unless your an engineer from the south..)

[Heavyd1980]

that is exactly what i was looking for. Thank you ISX you are all right!!!

[JOHNFAK]

Alright I will settle this once and for all with the pros and cons of each and you can decide for yourself. They excel in different areas so it's not always the easiest thing to just say "one is better". I am also only listing REAL differences.

[Mopar1973Man]

Well the 12V is a simple engine to work on but the 24V still has a few bonuses over... IMHO

[Rogan]

It's all a matter of opinion; that's the bottom line.I prefer my 12v over my 24, even to this day. I like the ease in which maintenance and repairs are performed on the 12v. Diagnosing is less painful, to me, on the 12v, due to the lack of electronics. And I like my right foot pedal physically connected to the throttle lever, rather than rely on the electronics to do it for me. We all know how finicky electronics can be.as for tuning and making power on a single income, 12V is the way to go. Case in point: 400+hp is easily obtainable for under $150-200 on a 12v. $200 gets you squat for a 24 valve.At 400_hp, my 5 spd 12v got in excess of 25-26mpg on the highway at 65-68mph. My 6spd 24v has never seen north of 18, since I've owned it (both on 265-75-16s and 3.55s.)The downside to the 12V is what I experienced; rack stuck full forward in the IP while passing someone, creating a runaway situation. It was quite scary. A reman'd Bosch pump was cheaper than fixing the old one. Oh, and this was at 105k mi.

[mwalser]

Great info, thanks!!!

[Heavyd1980]

see i keep hearing time and time again that the 12v gets better mileage by a long shot!!! so if the 24v is so much more advanced in the way of the computer and what not why does it not get better mileage???

[guesswho512]

emissions....the computer only care about meeting the emission laws at the time the vehicle was made

[Mopar1973Man]

emissions.... the computer only care about meeting the emission laws at the time the vehicle was made

Right on the money... But I'm working on getting around that...

[Heavyd1980]

i hope so cant wait to see the results!

[CSM]

Another consideration is the creature comforts. Aside from some of the very late build 12V trucks, 1998-1998.5 IIRC, they have the old interior. I personally prefer the new interior,the new seats, and the rear doors on the extended cab trucks. I also absolutely LOVE the in seat seat belts in the 98-02 pickups. The controls are mostly similar, the steering wheel on the post 98 trucks is more comfortable in my opinion. The a/c and heat work pretty much the same. The 1/4 windows locking mechanism is a little harder to pinch wimminz fingers in the newer trucks. The wind noise is still there in the newer trucks as well. The old ones are decent, but I have to say that they 94-97 pickups have one of the worst cupholders ever designed. They aren't worth much more than a place to clip an ipod or phone to. The cupholders in the 98 and newer automatics are great though. The dashes in the later build 24 valves seem to crack a lot. I have not heard of many of the older trucks have dash cracking issues.

[dripley]

my 96 had a cup thrower not a cup holder. also had a v10 and no cummins. it was a lot of fun but i dont miss it. gald i did not have it when gas was $4 a gallon. steering was not very good. needed work. but very much like my 02.`my 02 has the cracked dash. it is all still there but i am afraid to put anything on it for fear of it falling thru. would not trade the cummins though. i rebuilt the front end on this one though and it steers much better. still needs alittle more work though.

[dorkweed]

Another thing to consider also. My 3rd gen '04.5 weighs almost 1,000lbs. more than my 2nd gen '99 did. Roughly same crap in and on the truck!!!!