I am planning on getting a towrig/DD soon. I know that it is going to be a 2nd Gen Dodge Cummins. I am leaning toward a 12v for the lower price and cheaper mods. I am not going to "bomb" the motor much but I want a strong puller with good MPG's. Give me the pros and cons to both the 24v and 12v please. Also please give me any warning signs I need to look for when I look at the trucks. I know the obvious snowplow hookups, 5th wheel hookups, etc. What should I be looking for motor wise and drivetrain wise? I am ONLY considering manual transmissions. No auto's for me. Thanks Harley
IMHO, the 24v trucks are the way to go for most people. I'll start with the pro's and con's of the 12v trucks. Pros. 1. Great reliability from the engine itself. It has a fantastic injection pump that is nearly bulletproof and is the pump of choice when it comes to power. 2. It's a mechanical motor so it's a simple setup, not much for wiring and no computer. 3. They are easily modified. Cons. 1.IMHO, the 12v doesn't sound as cool as the 24v trucks. 2. They are easy to upgrade but it's kind of a guess on the power output. 3. The trannies, both the auto and manual are not as good as what is available behind the 24v trucks. THe auto isn't quite as refined as the later trucks, since it's not completely computer controlled and the 5spd manual has always been plagued with the 5th gear nut falling off. 4. A higher percentage of 12v trucks were equipped with 4.10 gears than the 24v, instead of the MUCH better 3.55's which are more common in the 24v's. ( 4.10's suck for everything but very heavy towing. The auto trucks shift too late and are slow as slugs, and the manuals rev up faster without getting boost up, this is though, not as much of a big deal if you tow a lot. As you mention it will be a DD, 3.55's are much better and obviously net much better fuel mileage) 5. The trucks themselves aren't as nice. The 98's recieved a make over in the interior and it's much nicer than the early interior. The one piece highback seats ROCK in the 24v's. 24V trucks, 98.5-'02 Pros, 1. Much nicer truck. Full leather with the highback seats. 2. The 24v's have aluminum radiators that work great and run fairly cooler than 12v trucks that come with standard radiators. 3. The auto is slightly improved over earlier 12v trans. The 6spd NV5600 can be found behind H.O '01-02 models and is an excellent combo and the 5600 has nearly no weak points. I've heard of output shaft failures but in a VERY small precentage behind trucks making big power. 4. Obviously, power output is considerably more in stock condition. 12v autos were 175HP 400ft lbs and manuals were 215HP 420ft lbs IIRC. Early 24v's are 215/420 in autos and later 01-02 were 235/460. Standard manual trucks were 235/460 and H.O. models were 245/505. 5. 12v truck mirrors suck. The 24v trucks had optional flip out towing mirrors, they are IMHO the best on the market. Cons. Weak injection pump. The VP44 is not the best pump in the world and will not tolerate low fuel pressure or dirty fuel. To top it off Dodge used a somewhat weak lift pump system that is designed to deliver the adequite fuel pressure the VP44 desperately needs to survive and not overheat. Many trucks have failed lift pumps that result in killing the main injection pump. THere are fixes for these problems, if you are interested I can fill you in on the ones I know of. Regardless, It's a small set back that can be fixed. I am very biased, but I believe the 24v's are SOOO much better than the earlier trucks. Making power is much EASIER in my opinion since you can have multiple power levels at the touch of a button. In and out the trucks are better IMHO. Another thing...are you sure you are set on a manual only truck? if it's simply because of the "rumors" of the Dodge autos than I would do some research. If you already have than thats your decision and great. The autos aren't that bad and are the ticket when it comes to making power. To somewhat of a suprise the standard output auto trucks from '01-02 can flow more fuel with chips than the H.O model. For some reason the ETC S.O pump can flow more fuel than the ETH H.O pump. I have even heard the S.O. injectors are slightly larger to match the ETC pump. Mileage is about the same between 12 and 24 trucks.
My 24V is gets between 19 and 20mpg. It's been around 20 lately, which is not uncommon from what I've read. It's mostly city driving. About 1/3 of my comute is on the interstate but it is usually slow due to rush hour. I guess I really can't complain about that, most people are suprised to hear it is that high. From what I've expierenaced and read I would expect no less that 18 with a manual and no less than 17 with an auto for empty comuting and more on the highway. It was down around 18 until I learned how it liked to be driven the best. Fuel treatments help too and in my case it was payin for half or a little more of the cost of the treatments. But then diesel is a bit more expensive now. Edit: It has 3.55 gears and I think the tires are 265/75's
So 12 and 24V's seem to have about the same mileage. Of course too many variables exist between vehicles/conditions/loads/driver to make it a true comparison, but overall, it seems that they are very close. When you consider the weight of these rigs, 18-20mpg is doing damn good.
I'm running 315/75/16 tires and with hand calculating and adjusting for tire size over stock I get between 18-21 +/- depending on how much highway, etc. This is with 3.55 gears. I'm very happy with the mileage. I'll be adding some F1 1.6 injectors by the spring and reliable info says I'll get 1-2 more mpg out of them along with the increase in power. waytogo
I get about 15 in town and 20 on the highway. I have a further spread than some guys.... big feet I guess... :doah: 24V and 3.55's. I've learned over talking to other Dodge guys that mileage varies a lot with these trucks. For example, my dad can't seem to get over about 17.5 on the highway, if that, and only about 15 in town. His is a 6spd H.O. On the other hand my grandpa swears he gets 25mpg on the highway with his '99 2wd auto Ram. I have never seen any difference in mileage between 12 and 24v engines.
I'm running(2005) 3.73's with the towing package on the 24 valve cummins with an automatic and I get over 22 mpg on the flat without a load.
Mileage If I keep it under 70mph, I can get 19 to 21mpg. I live in some hilly country with long steep grades and wind. I am running 285/75 R 16 and hand calculate the mileage to correct for the difference.
I opted to find a 12v when I bought mine. I only have $50 into engine mods and check out my performance http://www.putfile.com/mnorby and that is only my straight pipe and BHAF air filer.... plus 45 min to take my fuel plate out and grind it into a #100. I also run 315/75 and last time I actually checked my mileage (run shop fuel alot in 10-15 gal incruments)I got 21.5 mpg pulling empty trailer from Powell, WY to Casper, Wy. Was pretty proud. IMO if you like to do thinks yourself and tinker get a 12v. If you like to just bolt on and go get a 24v. If you opt for the 24v though I HIGHLY suggest you get a fuel pressure gauge ASAP. If you do any mods get a Pyro and boost gauge imediataly too and if auto tranny get a tranny temp gauge.
when fuel prices sky rocketed, I really started paying attention to the way I drive my '01 2500 2wd. I don't put many miles on my truck anymore... only ~6 miles a day (3 miles to work). no hiway, all lights and stop and go and i've been pretty proud of milkin' my 5 speed for 16.5mpg. Towing the K5 on a 3300 pound trailer I've been getting about 12mpg, but its pretty hilly country on the way to and from our wheeling spots. haven't logged any real hiway miles unloaded yet. truck is stock other than straight pipe and k&n oem filter replacement.
24v MPG I just returned from a run to Pittsburg, pulled a few grades loaded. I backed down from 68 mph to 63 mph, 1900 rpm to 1750 rpm and mpg increased from 12.5 to 14, pulling 10K lbs. That is a 24v, auto, modified with 3:55 gear. I get 19-20 empty truck at 70 mph.
