My Experience with a 2015 Ram 2500 6.4 Crew Cab
I don’t know if I needed to start another 6.4 thread since there are already so many but hey why not. The reason I thought a new one needed to be started is because I think there is a lot of miss information about the 6.4 by members that don’t own one, and are only writing about what they have “heard” or believe. I think I have a little different perspective than most members and I am an owner. Very few actual owners compared to non owners have voiced opinions on the 6.4. But for some reason there are plenty of non owners that feel they have the experience with a TV to make an educated review of it.
I am a retired auto tech with master certification from ASE, Chrysler and Ford. I was a tech for 15 years at the same Chrysler dealer 2 different time periods. I also worked at a ford dealer for 3 years and at an independent shop for 2 years. The past 8 years I have worked in the auto industry as a independent self employed inspector. I am contracted by extended warranties, manufacturers, and other entities. To do 3rd party inspections on vehicles needing mechanical repairs. I am asked to give my opinion as to the cause of failure on the vehicles. I am also contracted by the Better Business Bureau to give a 3rd party assessment of vehicles for possible lemon law buy backs. I have inspected almost any road, off road, or water operated vehicle in the past 8 years. Along with some other odd items.
I did a lot of research on the 6.4 motor, 2015 2500 Ram chassis, and transmission prior to my purchase. This is the 5th dodge truck I have owned but I have not owned another brand of truck. I did shop the other 2 domestic makes and did consider them but not seriously. My research consisted of verbally talking with several current 2500 6.4 owners, techs, and service managers and advisors. I read a lot of threads on this forum and others as well. Along with as much information on the internet as I could reasonably find.
I also considered a Cummins very seriously. I have not owned a Cummins in the past because I have not had a need for a heavy duty TV until this time. However I have extensive experience with the Cummins 5.9, 6.7, and 8.3 from a mechanical and technical side. I have a long list of reasons for not wanting a diesel TV. My trucks are not my daily drivers. They are tools. I use them for towing a 26 ft 5500 lb TT, for hunting, and for hauling payloads of various things. I only tow 10-15 times a year some long trips never through the mountains, and trips usually 250 miles or less. I do tow every few years a longer trip of 700-1000 miles.
The TT I currently have does not need to be towed by a ¾ or larger vehicle however in the near future we will be moving to a larger trailer probably a 5th wheel up to 12k lbs. I traded a 2012 Ram Laramie 1500 4x4 with a 5.7 545RFE trans, 3.55 gears, and about 29k miles on it I had purchased new. The new TV is a 2015 Ram 2500 Laramie with a 6.4 66RFE, 4.10 gears, that I also purchased new. The old truck I owned and it made more sense to move to a larger TV now then do the trailer and TV at the same time. And I got a really really good deal on trade in of my 2012.
After my years as a technician and inspector, I firmly believe a half ton truck should not tow anything more than 70% of its tow rating and expect longevity from its components. The engines in these vehicles have the power that heavy duty engines from a few year s ago did. However the same rear differential and light duty transmissions are still being used. Many times with only 1 or 2 extra gears added. I have seen too many failures due to towing near the capacity in half tons, to make me uncomfortable with towing anything larger than I owned with a half ton tow vehicle of any make. Can the vehicle do it? Yes. Can the vehicle do it consistently without premature failures of the driveline components? No. My experience with ¾ ton and 1 ton vehicles paints a different picture. I believe these vehicles are capable of towing at or even slightly above, their rating continuously without risk of premature failures to the driveline. The manufactures know that very few light duty vehicles are used to tow at their limits compared to medium duty and heavy duty vehicles. It is my opinion that is why they stand behind them with a warranty even though the tow ratings on them are so high.
The 2012 Ram I used to tow the TT pulled it very well. However the transmission while in tow haul would hunt between 4th and 5th gears. 5th was too high a gear for the load but 4th was lower than it needed. The transmission did not have the option of locking out a gear unless I shifted manually. I averaged 9 mpg with little wind front or behind. If there was much of a head wind then the truck would stay in 4th constantly and mileage fell to about 7.5. These are hand calculated numbers. I eventually did not tow with crusie any more, so I could keep the truck in 5th longer by accelerating down hills and letting the speed drop up hills (most hills are fairly small). Larger hills the truck would never need lower than 3rd and still could accelerate easily on any grade hill. I was never in altitude higher than 6k feet. I tow with a 14k equalizer 4pt hitch that eliminates all sway (I highly recommend this hitch for any TT). I try to keep my speed while towing at about 62-65 mph, usually at 60 on roads with a 55 mph speed limit. I did tow the TT with my brothers 2011 RAM 5.7 with 3.92 gears and it did not seem to keep the trans in 5th any longer with the cruise on. But I did not have the opportunity to tow it with an 8 speed transmission.
The new Ram 2500 I have had since June 1st. It tows my TT very easily which is to be expected since the truck has a tow rating of 15k and change. It do not use tow haul but I lock out 6th gear, however unless down a steep hill or a long stretch of decline with a tailwind the trans will not shift into 6th anyway. It very rarely shifts down to 4th unless the hill is steep and long, almost always in 5th which is a low over drive gear ratio. The trailer I tow bucks a lot of wind. It is very tall (10.5 ft) and this adds to the drag on the vehicle which the mileage on the 2012 and the 2011 I towed with indicated. In the new vehicle which has 2k miles on it I average 10.5 mpg with a slight head wind. And will get up to 12.5 with a modest tailwind. I did not buy this vehicle with mpg in mind though. The amount of miles I put on towing and unloaded makes a more fuel efficient engine less important. I average 18.5 mpg unloaded flat roads 60 mph with no head or tailwind. I averaged 20.5 mpg with the 1500 unloaded flat roads at 60 mph. All of these numbers are hand calculated while burning 87 octane gas with 15% ethanol. Mixed driving I average 16.5 with the half ton, 14 with the ¾ ton.
After towing my current TT 1400 miles this summer I have no reason to believe this motor, chassis, and transmission will not handle a 12k lb 5th wheel comfortably. The added weight does not effect the towing performance of a vehicle nearly as much as wind resistance. And most 5th wheel s will not sit much more than 2ft higher than my current TT. My experience towing with the newer motor and transmission coincides with what most other 5th wheel flat land and low elevation hill owners have experienced. I am confident this vehicle is very capable of handling its towing rating. Elevation does severely hamper gas engines. However an owner making very very seldom climbs in elevation should still be satisfied with this combination. But if towing heavy frequently in elevation above 7k I would seriously consider the 6.7 cummins engine..
I do not believe the Ike Gauntlet is a test that that should be reasonably considered for any person that does not tow at elevation. Vehicles today are all tested at the Davis Dam road in Arizona that has some elevation and an equally steep climb. This is used to simulate what more than 90% of towers will experience. The results from these tests are what the manufactures report. Those of you that repeatedly site the ike gauntlet test as a reason to down play the 6.4’s performance only have it as evidence to support your claim. And the manufacture admits to limiting the truck’s performance under those circumstances for longevity of the components. The Eisenhower tunnel is a section of interstate that very few people will ever drive with a very heavy trailer behind. My research and experience can support my opinion that the 6.4 hemi with the 66RFE transmission is capable of towing what it is rated for. And I believe it should be strongly considered for those people that do not want or need a diesel TV.
I apologize for this being so long and it reading like a book report. But tough its what you get now im not rewriting it. I felt I needed to explain my back ground and experience to support my opinion with the Ram 2500 6.4. Considering this is my first post even though I have been a long time lurker. And BTW all trucks are I have towed with recently have been Crew Cabs.
I am a retired auto tech with master certification from ASE, Chrysler and Ford. I was a tech for 15 years at the same Chrysler dealer 2 different time periods. I also worked at a ford dealer for 3 years and at an independent shop for 2 years. The past 8 years I have worked in the auto industry as a independent self employed inspector. I am contracted by extended warranties, manufacturers, and other entities. To do 3rd party inspections on vehicles needing mechanical repairs. I am asked to give my opinion as to the cause of failure on the vehicles. I am also contracted by the Better Business Bureau to give a 3rd party assessment of vehicles for possible lemon law buy backs. I have inspected almost any road, off road, or water operated vehicle in the past 8 years. Along with some other odd items.
I did a lot of research on the 6.4 motor, 2015 2500 Ram chassis, and transmission prior to my purchase. This is the 5th dodge truck I have owned but I have not owned another brand of truck. I did shop the other 2 domestic makes and did consider them but not seriously. My research consisted of verbally talking with several current 2500 6.4 owners, techs, and service managers and advisors. I read a lot of threads on this forum and others as well. Along with as much information on the internet as I could reasonably find.
I also considered a Cummins very seriously. I have not owned a Cummins in the past because I have not had a need for a heavy duty TV until this time. However I have extensive experience with the Cummins 5.9, 6.7, and 8.3 from a mechanical and technical side. I have a long list of reasons for not wanting a diesel TV. My trucks are not my daily drivers. They are tools. I use them for towing a 26 ft 5500 lb TT, for hunting, and for hauling payloads of various things. I only tow 10-15 times a year some long trips never through the mountains, and trips usually 250 miles or less. I do tow every few years a longer trip of 700-1000 miles.
The TT I currently have does not need to be towed by a ¾ or larger vehicle however in the near future we will be moving to a larger trailer probably a 5th wheel up to 12k lbs. I traded a 2012 Ram Laramie 1500 4x4 with a 5.7 545RFE trans, 3.55 gears, and about 29k miles on it I had purchased new. The new TV is a 2015 Ram 2500 Laramie with a 6.4 66RFE, 4.10 gears, that I also purchased new. The old truck I owned and it made more sense to move to a larger TV now then do the trailer and TV at the same time. And I got a really really good deal on trade in of my 2012.
After my years as a technician and inspector, I firmly believe a half ton truck should not tow anything more than 70% of its tow rating and expect longevity from its components. The engines in these vehicles have the power that heavy duty engines from a few year s ago did. However the same rear differential and light duty transmissions are still being used. Many times with only 1 or 2 extra gears added. I have seen too many failures due to towing near the capacity in half tons, to make me uncomfortable with towing anything larger than I owned with a half ton tow vehicle of any make. Can the vehicle do it? Yes. Can the vehicle do it consistently without premature failures of the driveline components? No. My experience with ¾ ton and 1 ton vehicles paints a different picture. I believe these vehicles are capable of towing at or even slightly above, their rating continuously without risk of premature failures to the driveline. The manufactures know that very few light duty vehicles are used to tow at their limits compared to medium duty and heavy duty vehicles. It is my opinion that is why they stand behind them with a warranty even though the tow ratings on them are so high.
The 2012 Ram I used to tow the TT pulled it very well. However the transmission while in tow haul would hunt between 4th and 5th gears. 5th was too high a gear for the load but 4th was lower than it needed. The transmission did not have the option of locking out a gear unless I shifted manually. I averaged 9 mpg with little wind front or behind. If there was much of a head wind then the truck would stay in 4th constantly and mileage fell to about 7.5. These are hand calculated numbers. I eventually did not tow with crusie any more, so I could keep the truck in 5th longer by accelerating down hills and letting the speed drop up hills (most hills are fairly small). Larger hills the truck would never need lower than 3rd and still could accelerate easily on any grade hill. I was never in altitude higher than 6k feet. I tow with a 14k equalizer 4pt hitch that eliminates all sway (I highly recommend this hitch for any TT). I try to keep my speed while towing at about 62-65 mph, usually at 60 on roads with a 55 mph speed limit. I did tow the TT with my brothers 2011 RAM 5.7 with 3.92 gears and it did not seem to keep the trans in 5th any longer with the cruise on. But I did not have the opportunity to tow it with an 8 speed transmission.
The new Ram 2500 I have had since June 1st. It tows my TT very easily which is to be expected since the truck has a tow rating of 15k and change. It do not use tow haul but I lock out 6th gear, however unless down a steep hill or a long stretch of decline with a tailwind the trans will not shift into 6th anyway. It very rarely shifts down to 4th unless the hill is steep and long, almost always in 5th which is a low over drive gear ratio. The trailer I tow bucks a lot of wind. It is very tall (10.5 ft) and this adds to the drag on the vehicle which the mileage on the 2012 and the 2011 I towed with indicated. In the new vehicle which has 2k miles on it I average 10.5 mpg with a slight head wind. And will get up to 12.5 with a modest tailwind. I did not buy this vehicle with mpg in mind though. The amount of miles I put on towing and unloaded makes a more fuel efficient engine less important. I average 18.5 mpg unloaded flat roads 60 mph with no head or tailwind. I averaged 20.5 mpg with the 1500 unloaded flat roads at 60 mph. All of these numbers are hand calculated while burning 87 octane gas with 15% ethanol. Mixed driving I average 16.5 with the half ton, 14 with the ¾ ton.
After towing my current TT 1400 miles this summer I have no reason to believe this motor, chassis, and transmission will not handle a 12k lb 5th wheel comfortably. The added weight does not effect the towing performance of a vehicle nearly as much as wind resistance. And most 5th wheel s will not sit much more than 2ft higher than my current TT. My experience towing with the newer motor and transmission coincides with what most other 5th wheel flat land and low elevation hill owners have experienced. I am confident this vehicle is very capable of handling its towing rating. Elevation does severely hamper gas engines. However an owner making very very seldom climbs in elevation should still be satisfied with this combination. But if towing heavy frequently in elevation above 7k I would seriously consider the 6.7 cummins engine..
I do not believe the Ike Gauntlet is a test that that should be reasonably considered for any person that does not tow at elevation. Vehicles today are all tested at the Davis Dam road in Arizona that has some elevation and an equally steep climb. This is used to simulate what more than 90% of towers will experience. The results from these tests are what the manufactures report. Those of you that repeatedly site the ike gauntlet test as a reason to down play the 6.4’s performance only have it as evidence to support your claim. And the manufacture admits to limiting the truck’s performance under those circumstances for longevity of the components. The Eisenhower tunnel is a section of interstate that very few people will ever drive with a very heavy trailer behind. My research and experience can support my opinion that the 6.4 hemi with the 66RFE transmission is capable of towing what it is rated for. And I believe it should be strongly considered for those people that do not want or need a diesel TV.
I apologize for this being so long and it reading like a book report. But tough its what you get now im not rewriting it. I felt I needed to explain my back ground and experience to support my opinion with the Ram 2500 6.4. Considering this is my first post even though I have been a long time lurker. And BTW all trucks are I have towed with recently have been Crew Cabs.
