I will echo what many others have said on here. If you search for my username you can probably find a few other posts where I explain our justification for upgrading from a 1998 Nissan Frontier to a 2001 Dodge Ram 2500 CTD. Prior to the Frontier, I owned a '94 Toyota 4Runner. I previously lived in Wyoming and now live in Oregon.
As others have mentioned, what is your definition of remote roads and trails or "off-road". For most of places in the west, this truck will get you down any road or trail that is open to vehicles and not specifically designed for modified rock crawler type vehicles. What does that mean? Well, most USFS and BLM lands are now implementing travel management plans, and the main purpose of these plans is to specifically authorize legal vehicle travel roads. All others will be closed to vehicular access. Some areas have already started, some are in process. That being said, a Dodge CTD will get you down almost all of these roads/trails.
Specific answers to your post below...
I'll be looking to get multiple uses out of my next vehicle (hunting, hauling cargo, exploring 4x4 trails/roads, camping) YES
I will need something that can tow when I need it to. YES
I'm aware of the whole argument that "diesels aren't worth it unless you plan to tow all the time." I'm willing to pay a little extra for fuel and maintenance if this truck can meet my needs. NOT NECESSARILY
I know the diesel 2500's really didn't come with anything in the way of offroading equipment, so I'd plan on getting ARB air lockers, at least 12k winch,and a front bumper at a minimum. IS THIS NEEDED? A SET OF CHAINS AND MAXTRAX MIGHT BE A BETTER INVESTMENT.
1) I've read the 5.9L cummins (stock) can get about 18 mpg city, and 22 mpg highway. Is that accurate? MINE IS A 2001 SO NOT A DIRECT COMPARISON, BUT I AM CONSISTENTLY AT 20.5 WITH A MIX OF CITY AND HWY IN THE SUMMER, 19.5 IN THE WINTER.
2) Besides possible injector failures, are there any big issues with the 2005-2007 cummins? NOT A DIRECT COMPARISON, ALTHOUGH I WOULD CONCUR WITH OTHERS THAT THE MAJOR ARE IS FRONT END COMPONENTS
3) Will this rig be able to go down most 4x4 trails and roads, despite its size and weight? I'm not looking to turn this into a dedicated rock-crawler, but at the same time, I want to be able to get through/over restrictive terrain. YES, AND SEE COMMENT ABOVE. IF THE TRAIL OR ROAD WAS DESIGNED FOR TRUCKS (AND NOT ATVs), THEN IT MOST LIKELY WILL
4) Any issues with this engine starting up in cold weather (-25 C and below) in stock form? I know the engine relies on a block heater instead of glow plugs. Do people in cold climates usually get aftermarket heaters for this engine? MINE HAS STARTED DOWN TO -28F WHILE ELK HUNTING. I HAVE A BLOCK HEATER TO USE WHILE AT MY HOUSE. I WOULD ALSO SAY ALWAYS TREAT YOUR FUEL WITH A FUEL ADDITIVE IN THE WINTER, EVEN IF IT IS ALREADY TREATED. I USE SCHAEFFERS, BUT YOU CAN READ UP ON ALL THE DIFFERENT BRANDS. I BOUGHT MY TRUCK IN 2011 AND IT HAS ONLY HAD A FUELING ISSUE ONCE, THIS PAST WINTER WHEN MY FUEL CONDENSED IN THE TANK AFTER A LONG COLD DAY OF DRIVING OFF ROAD TO AN ELK HUNTING SITE. I SURMISE THAT THE FUEL WAS WARMED FROM THE LONG DRIVE OUT AND THEN IT SAT OVERNIGHT WITH VERY COLD AIR TEMPS, CAUSING CONDENSATION IN THE TANK WHICH INTRODUCED WATER INTO THE FUEL. THE NEXT MORNING MY TRUCK WOULD START, RUN FOR A FEW MINUTES, THEN DIE FROM THE WATER. DRAINED THE FUEL FILTER, ADDED DIESEL 911, RIGGED UP A HAIR DRYER, AND IT WAS FINE AFTER IDLING FOR ABOUT 30 MINUTES. I HAD NOT TREATED THE FUEL WITH SCHAEFFERS DURING THAT INCIDENT AND I LEARNED MY LESSON. I HAVE NEVER HAD MY FUEL GEL WHILE USING SCHAEFFERS, AND I HAVE STARTED THE ENGINES MANY TIMES IN BELOW ZERO CONDITIONS WITHOUT HAVING THE ENGINE ON A BLOCK HEATER.
I'm willing to live with the maintenance and reliability of a 10 year old truck. My biggest concern honestly is whether its size and weight (especially the added weight of the cummins) will hinder my ability to explore and drive remote roads and trails. NO
Edit: I forgot to ask - 5) Is it pretty much a given that I'll need to upgrade/swap out the front suspension and steering components? I've heard that the Ram 2500's prior to 2013 had an issue known as the "death wobble." I HAD THE FRONT AXLE REBUILT TO REPLACE THE SEALS AND BEARINGS (NOT RELATED TO DEATH WOBBLE BUT ALSO SOMETHING TO CONSIDER), I REPLACED SHOCKS ALL AROUND, NEW BALL JOINTS, U-JOINTS, UPGRADED TRACK BAR, STEERING STABILIZER, UPGRADED STEERING LINKAGE. NO ISSUES BEFORE OR AFTER ALL THAT WORK, BUT ON A 12 YEAR OLD TRUCK SOME OF THAT WAS JUST GENERAL MAINTENANCE. I WOULD ALSO STRESS THAT MANY OF THE REPORTS OF DEATH WOBBLE ARE ON TRUCKS THAT ARE LIFTED, LARGER TIRES, AND AFTERMARKET WHEELS, SO STAYING CLOSE TO STOCK IS BENEFICIAL. MY TRUCK CAME WITH HUTCHINSON BEADLOCKS AND 285 TIRES WHICH I SWAPPED TO STOCK RIMS AND 255/85 R 16 TIRES, DECREASING MY WEIGHT PER WHEEL BY ABOUT 25 LBS AND BRINGING THE WHEEL OFFSET BACK TO STOCK. THIS CHANGE ALONE VASTLY IMPROVED MY STEERING BEFORE I DID ANY OF THE OTHER FRONT END UPGRADES.
As others have mentioned, what is your definition of remote roads and trails or "off-road". For most of places in the west, this truck will get you down any road or trail that is open to vehicles and not specifically designed for modified rock crawler type vehicles. What does that mean? Well, most USFS and BLM lands are now implementing travel management plans, and the main purpose of these plans is to specifically authorize legal vehicle travel roads. All others will be closed to vehicular access. Some areas have already started, some are in process. That being said, a Dodge CTD will get you down almost all of these roads/trails.
Specific answers to your post below...
I'll be looking to get multiple uses out of my next vehicle (hunting, hauling cargo, exploring 4x4 trails/roads, camping) YES
I will need something that can tow when I need it to. YES
I'm aware of the whole argument that "diesels aren't worth it unless you plan to tow all the time." I'm willing to pay a little extra for fuel and maintenance if this truck can meet my needs. NOT NECESSARILY
I know the diesel 2500's really didn't come with anything in the way of offroading equipment, so I'd plan on getting ARB air lockers, at least 12k winch,and a front bumper at a minimum. IS THIS NEEDED? A SET OF CHAINS AND MAXTRAX MIGHT BE A BETTER INVESTMENT.
1) I've read the 5.9L cummins (stock) can get about 18 mpg city, and 22 mpg highway. Is that accurate? MINE IS A 2001 SO NOT A DIRECT COMPARISON, BUT I AM CONSISTENTLY AT 20.5 WITH A MIX OF CITY AND HWY IN THE SUMMER, 19.5 IN THE WINTER.
2) Besides possible injector failures, are there any big issues with the 2005-2007 cummins? NOT A DIRECT COMPARISON, ALTHOUGH I WOULD CONCUR WITH OTHERS THAT THE MAJOR ARE IS FRONT END COMPONENTS
3) Will this rig be able to go down most 4x4 trails and roads, despite its size and weight? I'm not looking to turn this into a dedicated rock-crawler, but at the same time, I want to be able to get through/over restrictive terrain. YES, AND SEE COMMENT ABOVE. IF THE TRAIL OR ROAD WAS DESIGNED FOR TRUCKS (AND NOT ATVs), THEN IT MOST LIKELY WILL
4) Any issues with this engine starting up in cold weather (-25 C and below) in stock form? I know the engine relies on a block heater instead of glow plugs. Do people in cold climates usually get aftermarket heaters for this engine? MINE HAS STARTED DOWN TO -28F WHILE ELK HUNTING. I HAVE A BLOCK HEATER TO USE WHILE AT MY HOUSE. I WOULD ALSO SAY ALWAYS TREAT YOUR FUEL WITH A FUEL ADDITIVE IN THE WINTER, EVEN IF IT IS ALREADY TREATED. I USE SCHAEFFERS, BUT YOU CAN READ UP ON ALL THE DIFFERENT BRANDS. I BOUGHT MY TRUCK IN 2011 AND IT HAS ONLY HAD A FUELING ISSUE ONCE, THIS PAST WINTER WHEN MY FUEL CONDENSED IN THE TANK AFTER A LONG COLD DAY OF DRIVING OFF ROAD TO AN ELK HUNTING SITE. I SURMISE THAT THE FUEL WAS WARMED FROM THE LONG DRIVE OUT AND THEN IT SAT OVERNIGHT WITH VERY COLD AIR TEMPS, CAUSING CONDENSATION IN THE TANK WHICH INTRODUCED WATER INTO THE FUEL. THE NEXT MORNING MY TRUCK WOULD START, RUN FOR A FEW MINUTES, THEN DIE FROM THE WATER. DRAINED THE FUEL FILTER, ADDED DIESEL 911, RIGGED UP A HAIR DRYER, AND IT WAS FINE AFTER IDLING FOR ABOUT 30 MINUTES. I HAD NOT TREATED THE FUEL WITH SCHAEFFERS DURING THAT INCIDENT AND I LEARNED MY LESSON. I HAVE NEVER HAD MY FUEL GEL WHILE USING SCHAEFFERS, AND I HAVE STARTED THE ENGINES MANY TIMES IN BELOW ZERO CONDITIONS WITHOUT HAVING THE ENGINE ON A BLOCK HEATER.
I'm willing to live with the maintenance and reliability of a 10 year old truck. My biggest concern honestly is whether its size and weight (especially the added weight of the cummins) will hinder my ability to explore and drive remote roads and trails. NO
Edit: I forgot to ask - 5) Is it pretty much a given that I'll need to upgrade/swap out the front suspension and steering components? I've heard that the Ram 2500's prior to 2013 had an issue known as the "death wobble." I HAD THE FRONT AXLE REBUILT TO REPLACE THE SEALS AND BEARINGS (NOT RELATED TO DEATH WOBBLE BUT ALSO SOMETHING TO CONSIDER), I REPLACED SHOCKS ALL AROUND, NEW BALL JOINTS, U-JOINTS, UPGRADED TRACK BAR, STEERING STABILIZER, UPGRADED STEERING LINKAGE. NO ISSUES BEFORE OR AFTER ALL THAT WORK, BUT ON A 12 YEAR OLD TRUCK SOME OF THAT WAS JUST GENERAL MAINTENANCE. I WOULD ALSO STRESS THAT MANY OF THE REPORTS OF DEATH WOBBLE ARE ON TRUCKS THAT ARE LIFTED, LARGER TIRES, AND AFTERMARKET WHEELS, SO STAYING CLOSE TO STOCK IS BENEFICIAL. MY TRUCK CAME WITH HUTCHINSON BEADLOCKS AND 285 TIRES WHICH I SWAPPED TO STOCK RIMS AND 255/85 R 16 TIRES, DECREASING MY WEIGHT PER WHEEL BY ABOUT 25 LBS AND BRINGING THE WHEEL OFFSET BACK TO STOCK. THIS CHANGE ALONE VASTLY IMPROVED MY STEERING BEFORE I DID ANY OF THE OTHER FRONT END UPGRADES.