RAM 1500 Diesel Forum banner

21 - 40 of 48 Posts

·
Registered
Joined
·
7 Posts
The OP doesn't mention what the rear differential ratio is on his truck. Wouldn't that make some difference? Between say a 3.25, 3.55, or 3.92 :1? Seems to me that a truck with a 3.92 running at a steady 60 mph will be turning a higher RPM than one with a 3.25 running a steady 60 mph. I suspect that a sustained higher RPM would, over time at least, result in somewhat reduced fuel mileage. Not sure if it would make that much difference though.
 

·
Registered
Joined
·
4,831 Posts
The OP doesn't mention what the rear differential ratio is on his truck. Wouldn't that make some difference? Between say a 3.25, 3.55, or 3.92 :1? Seems to me that a truck with a 3.92 running at a steady 60 mph will be turning a higher RPM than one with a 3.25 running a steady 60 mph. I suspect that a sustained higher RPM would, over time at least, result in somewhat reduced fuel mileage. Not sure if it would make that much difference though.
3.55 and 3.92 are the only options. They're so close together it doesn't make much difference at all.
 

·
Registered
Joined
·
903 Posts
So, mine is a 2016, 3.55, 20", rambox. It's factory stock with all updates done. I haven't gone far since the VA7, so the mileage is just off the EVIC and it's crap at 22.5US MPG or 27MPG CDN. Before I started having all these updates, last summer, when I was just driving it, my highway mileage was running at 32-35mpg CDN which is about 27mpg US. I stored it for the winter and just got it out, so now I can start seeing how the latest updates will affect it. From all indications on the EVIC, I am headed in that good mileage direction again as my cumulative mileage continues to decrease in number ... 11 - 10.9 - 10.8 - etc. I'll be doing a bit longer tomorrow, about 150km highway, so well see then.
 

·
Registered
Joined
·
20 Posts
I am the second owner of a gorgeous 2016 Laramie. I bought it with just over 30,000 last August. The original owner put 20" wheels on it almost immediately after he bought it, and he never reset one of the trip meters thereafter. I'll try to post photos showing that in 39,650 miles (out of the 40,478 total on it), the truck has averaged 19.2 MPG at an average 29 MPH. The stats for the most recent 2900 miles are similar: 19.2 MPG at and average 22 MPH. So it's clear that the truck has done more city/low speed traveling than long highway, high-speed miles. The engine hours show 155 hours idling, and 1213 hours driving. Without the idle time, the math says the average speed would have been 33 MPH. The AEM recall was done on the truck just a month or two before I bought it.

I know the 20" wheels throw the mileage off by about 4%, but even adding for that it brings the average MPG to 19.968 - darn close to 20. That's a far cry from the 25, 27, or even 30 I've seen posted on this forum.

I've done very little towing with the truck in the 10,000 miles I've put on it, and I don't think the previous owner did much, if any towing. They used it as a big, comfortable commuter from their home on the beach into town for doctor's appointments and such - about an hour's drive each way on two-lane highway, probably 55 mph speeds. I take it on a 120 mile round-trip on the freeway about once a month. If I'm careful to stay at 70 mph or just under, I can eventually coax it up to 19.8, when I've started out on the trip with an average of around 17. I've never seen the meter read 20 MPG as an average, yet.

Anybody got any ideas?
I have 2016 ED... Early on, less than 5K miles we made a trip from Richmond, VA up to Cape Cod & on to Bar Harbor Me. Over the course of that trip, we averaged 27.5 mpg. This included daily trips up and down Cadillac Mtn., in Acadia National Park. Typically I was getting 22 MPG in town and 26 on trips on the freeway over an hour each way. Six months later and with no engine fault codes indicated, my milage dropped to 17 in Town and 20 HWY. I had taken it in several times complaining about what appeared to be a problem, sluggish response to throttle and milage. They did some more extensive troubleshooting and found that the Turbo had failed. There were no fault codes recorded. My milage has never recovered much since then. Following the turbo replacement, my milage came up a little 19 in Town and 23 on the hwy. I now have 34K miles on the truck. The AEM affected performance and dropped my mpg ever so slightly. I've only had one regeneration notification which happened at about 22K, though DEF is consumed. Wth MPG where it is, I'm not better off than someone driving the same truck with the Hemi.
 

·
Registered
Joined
·
78 Posts
I am the second owner of a gorgeous 2016 Laramie. I bought it with just over 30,000 last August. The original owner put 20" wheels on it almost immediately after he bought it, and he never reset one of the trip meters thereafter. I'll try to post photos showing that in 39,650 miles (out of the 40,478 total on it), the truck has averaged 19.2 MPG at an average 29 MPH. The stats for the most recent 2900 miles are similar: 19.2 MPG at and average 22 MPH. So it's clear that the truck has done more city/low speed traveling than long highway, high-speed miles. The engine hours show 155 hours idling, and 1213 hours driving. Without the idle time, the math says the average speed would have been 33 MPH. The AEM recall was done on the truck just a month or two before I bought it.

I know the 20" wheels throw the mileage off by about 4%, but even adding for that it brings the average MPG to 19.968 - darn close to 20. That's a far cry from the 25, 27, or even 30 I've seen posted on this forum.

I've done very little towing with the truck in the 10,000 miles I've put on it, and I don't think the previous owner did much, if any towing. They used it as a big, comfortable commuter from their home on the beach into town for doctor's appointments and such - about an hour's drive each way on two-lane highway, probably 55 mph speeds. I take it on a 120 mile round-trip on the freeway about once a month. If I'm careful to stay at 70 mph or just under, I can eventually coax it up to 19.8, when I've started out on the trip with an average of around 17. I've never seen the meter read 20 MPG as an average, yet.

Anybody got any ideas?
1st -never ever rely on the "Lie-O'Meter" on the dash. Always hand calculate your mileage and always top your tank so you know it's close to the same level when you fill. Second, what tires (Name and model) and exact size? Then go to Discount Tire's website and look for the tires and the spec. You want to know the weight and how close they are to stock. Third, 20" tires should have been stock on a 2016 Laramie. 4th, have a dealer reset your ECU for 20" tires. 5th, unless these are oversized tires 4% is not the error. Maybe 2%. 6th, your average speeds seems to indicate a lot of low speed driving, in which case 20 mpg is about right. And, lastly, there is an update for the AEM that you should be able to get at your local dealer at now charge along with any other recall service your truck may need. Are you in FCAs system so you are getting recall notices? If not get your truck updated by the dealer.
Regarding tire weight -heavier = lower mileage. I use 275/65-20 snow tires (Cooper Discoverer) which are heavy and they cost me about 2 mpg (along with the Winter fuel mix.)
 

·
Registered
Joined
·
7 Posts
Since we're on this discussion, I'm curious to know what the sweet spot RPM is for fuel mileage for the ED. In other words, on an interstate highway, where should I set my cruise control for maximum MPGs? I suggest RPM rather than speed because that should account for tire size and rear diff ratio. Hopefully I'll be able to do some open highway driving soon and when I do I'd like to see maybe 26 or 27 mpg out on the interstate.

I bought my 2016 ED just as the virus lockdown ensued and all I've done so far is local driving which is a combination of city and two-lane country roads. I haven't had an opportunity yet to drive on an interstate to evaluate it there but so far I'm reasonably happy with MPG. I've only run 1.5 tanks of fuel since I bought it in mid-February and I haven't measured it exactly but the EVIC shows between 20 and 21 when I'm making stops in town then after a couple of hours out on the two-lane it'll nudge up to 22 but then will drop back to somewhere between 20 and 21 again after a few trips in town.

For the record I really like this truck. It looks good, drives nice, smooth ride, nice interior, good stereo. I haven't experienced any of the lag or slow acceleration that some people complain about. I hope I don't jinx it but there is nothing about it that I don't like. Okay, there's maybe one tiny little nit to pick. For some reason the left side exhaust tip extends out past the bumper about an inch and a half further than the right side exhaust tip. But that's the only thing I've found so far that fails to meet expectations.
 

·
Registered
2020 Ram 4x2 Eco Gen III, Laramie crew, air susp. DSA rear end, barn door tail gate
Joined
·
111 Posts
in one of your pics, you have a kayak mounted, whoops, that has an affect on fuel also... you shared that the previous owner putted around and made short trips, diesels are meant to be a road warrior machine.... get the temps up on it, and run her for miles on end... and blow that EGR out... short trips to the grocery store kills these oil burners... and another thing, one way to blow her out, hook up to 5000 lbs. hit that tow haul button, and go run her for 100 mile road trip... she'll quit running likes she's got Corona virus...
 

·
Registered
2019 RAM 1500 Tradesman 4X2 EcoDiesel
Joined
·
107 Posts
GPS. Without one what you are considering is probably way off. Watch the speed on the GPS and compare that to the speedometer. Watch the odometer on the GPS and compare that to the odometer in the truck. Use the GPS readings and hand calculate to real results. If you cannot do these things you will never really know.
To check the odometer, I think it's easier to read the mileage off of the paddle markers along the highway. If you're on the same highway for 50 or 100 miles, you can get an extremely accurate calibration. The hardest thing is remembering to check after an hour or so. I assume you were referring to built-in navigation, which some of us don't have. I wouldn't be surprised if there is a phone app, though.
 

·
Registered
Joined
·
903 Posts
I assume you were referring to built-in navigation, which some of us don't have.
No, he is referring to a standalone GPS unit like a Garmin or Magellan. And yes, most cellular telephones have a GPS unit and there are free apps and maps available. I use the "Avenza" app on my iPhone 6 for walking and I use a Garmin GPSmap78 for fishing and hunting.
 

·
Registered
Joined
·
309 Posts
I thought we had all just accepted the fact that some of these trucks (mine included) don't get the advertised MPG. Even with GDE engine and trans tune, stock size tires, no frills, I'm still getting 21ish max MPG. Oh sure, sometimes the instant reads 27-28 for a mile or so, but I have never seen the average displayed at anywhere above 24. My hand calcs are usually at least 1mpg lower. I cruise control at 73 mph almost all the time on the freeway, and spend about half my miles on the freeway.

I wish MPG specs weren't just two numbers on a page. Or at least that they would tell you the conditions that they saw to get those two numbers. Some guy on flat ground Texas, that never sees more than 60mph is going to have different numbers than a guy driving in the Rockies with speed limits that can be as high as 80mph. Is anything wrong, or even special about either of those trucks? No. And if there is, you'll never get dealer to fully investigate it.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #33
Can't believe it's taken me a couple of months to get back to this post. Somethings been going on... Anyway, I wanted to say thanks to all you who responded. I learned a lot. You were absolutely right, those are stock wheels that come with the Laramie package. The original owner put new Michelins on at 7,000 miles. I thought he told me he replaced both wheels and tires, but it was just the tires. Had it on a 250 mile trip and the "Lie-O-Meter" did finally creep up to just a tad over 20 mpg. Will take your advice and filld it up to the first automatic shutoff point and will check the mileage by hand.
 

·
Registered
2019 RAM 1500 Tradesman 4X2 EcoDiesel
Joined
·
107 Posts
I wish MPG specs weren't just two numbers on a page. Or at least that they would tell you the conditions that they saw to get those two numbers. Some guy on flat ground Texas, that never sees more than 60mph is going to have different numbers than a guy driving in the Rockies with speed limits that can be as high as 80mph. Is anything wrong, or even special about either of those trucks? No. And if there is, you'll never get dealer to fully investigate it.
I think the EPA test description is available. Everyone realizes--or should--that the test gives a measurement under prescribed circumstances that probably don't perfectly match any one person's driving experience. They are useful for comparing one vehicle to another. Of course, the manufacturers know what the test is and can build to get the best MPG on the test (they wouldn't do that, would they?). We know that above a certain speed, increasing speed decreases mileage due to increased air and rolling resistance. We know that headwinds and rapid acceleration decrease mileage. However, if someone is getting 2/3 of the rated mileage at reasonable speeds and acceleration, something is wrong.
 

·
Registered
Joined
·
12 Posts
After 4 year of driving mine a 2016 Laramie 4x4 crew cab with 6'4" bed, fully loaded, air suspension, running boards, sprayed liners, LSD and bed mat plus another 150 lbs of stuff in the back. Normally one adult but many long trips with three adults and two labs. I track the mileage pretty close and here is what I have found:
Summer commute to work - 75 miles each way on freeway 74 mph - 26 mpg
Winter commute to work, winter blend and a lot of below zero on freeway and I add 200lbs of sand in the back - 23 mpg
Summer trips to the cabin - 175 miles each way, county highways 60 miles and hour average - 28 mpg
Towing - depending on the load but using a steel 4x8 trailer, electric brakes with 3 foot side walls and decking, a ramp and spare tire post and tire, carrying about 2500 lbs - 16-18 mpg. I use to have the weight of the trailer empty but can not find where I put that down, around 500 lbs seems to tickle my mind, the trailer is rated for 3500 lbs. The towing is usually to the cabin or moving kids.
I had one long summer trip through Iowa, much flatter terrain than WI which is rolling terrain and average HYW speed of 60 and calculated 30 mpg. Two adults and no trailer. Never have gotten that again.
I have used additives, about every other fill, with OPTI - XPD (used mostly for anti-freezing through the winter) and have not seen a change. I used hot shot extreme and have seem a very slight increase. I tend to concentrate on additives for anti - gelling or lubrication versus pure cetane and MPG increase.

I have found the sweet spot for my truck is around the 60-65 mph mark. Though it seems once I pass 74 mph, it appears to get better than the 70-73 range. But no real data on that as I do try to keep around the speed limits - my youthful get there as fast as I can days are long gone.
 

·
Registered
2015, ram 1500 longhorn, eco diesel
Joined
·
33 Posts
After 4 year of driving mine a 2016 Laramie 4x4 crew cab with 6'4" bed, fully loaded, air suspension, running boards, sprayed liners, LSD and bed mat plus another 150 lbs of stuff in the back. Normally one adult but many long trips with three adults and two labs. I track the mileage pretty close and here is what I have found:
Summer commute to work - 75 miles each way on freeway 74 mph - 26 mpg
Winter commute to work, winter blend and a lot of below zero on freeway and I add 200lbs of sand in the back - 23 mpg
Summer trips to the cabin - 175 miles each way, county highways 60 miles and hour average - 28 mpg
Towing - depending on the load but using a steel 4x8 trailer, electric brakes with 3 foot side walls and decking, a ramp and spare tire post and tire, carrying about 2500 lbs - 16-18 mpg. I use to have the weight of the trailer empty but can not find where I put that down, around 500 lbs seems to tickle my mind, the trailer is rated for 3500 lbs. The towing is usually to the cabin or moving kids.
I had one long summer trip through Iowa, much flatter terrain than WI which is rolling terrain and average HYW speed of 60 and calculated 30 mpg. Two adults and no trailer. Never have gotten that again.
I have used additives, about every other fill, with OPTI - XPD (used mostly for anti-freezing through the winter) and have not seen a change. I used hot shot extreme and have seem a very slight increase. I tend to concentrate on additives for anti - gelling or lubrication versus pure cetane and MPG increase.

I have found the sweet spot for my truck is around the 60-65 mph mark. Though it seems once I pass 74 mph, it appears to get better than the 70-73 range. But no real data on that as I do try to keep around the speed limits - my youthful get there as fast as I can days are long gone.
Is this with stock ECU?
 

·
Registered
Joined
·
12 Posts
Yes, no other tunes, though a little better at fluid changes versus schedule. Differentials are change at the 30,000 mark, oil around the 9,000 mark. All recalls have been done in last 6 to 8 months and from what I can tell slightly better at high speeds but slightly lower at slower speeds. I do stay with high grade number 2 that is not bio diesel when I can.
 

·
Registered
Joined
·
596 Posts
My 2019 F150 with 3.5 EB and 10 speed averages a hand calculated 20.5 mpg with my driving. With the cost difference of diesel here it's really a wash for me vs my old ED.
 

·
Registered
2016 Ram ED CC Limited 4x4 6'4" Rambox
Joined
·
20 Posts
I was going to post my own thread, but this seems to be a very similar discussion. I read through this and see a mix of reactions. I used this forum as a reference when I was looking up information on my search for a truck, but just joined to post my dilemma after finally purchasing the truck.

I just bought a 2016 Limited with 88,000 miles a 6'4" bed, ramboxes, air suspension, 3.55 ratio and aftermarket rims and tires (still 20" I believe, but slightly over-sized tires at 56lbs per tire). I live in Michigan and purchased the truck in South Dakota. We drove it back (about 772 miles) and on the final fill up we reset the trip odometer. The computer read 503 miles traveled when I filled up and I put 23.7 gallons in it (21.2 mpg), but with about 420+ miles or so of those miles being highway miles cruising between 73-75mph, I expected it to be much higher (the computer read an average of 22.3mpg after just the highway mileage). I can tell from the zip on my credit card statement that an actual 420 miles were driven on the highway from that fill up, but I don't know what that correlated to on my trip odometer.

I was thinking that I would be at at least 24-26mpg for this tank and then my typical driving would drop it to the 21-22mpg range, I am a little concerned because I purchased this truck specifically for the fuel efficiency. @hunter1234 has great results with a similar year and options, so I am quite intrigued at what the difference could be. I know it is really early so I will keep tracking, but wanted to get it out there.

I do want to get the GDE tune at some point, but I have the Mopar Max Coverage Warranty transferred to me for 2 more years, so I don't want to void that.

Any ideas. I am not overly mechanically inclined, but I want to do whatever is needed to get it up within reason.

Addition: I believe all the recalls have been completed on the truck (or at least they said they were being done last week) since they were "no sale recalls" for the dealership.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #40
I was going to post my own thread, but this seems to be a very similar discussion. I read through this and see a mix of reactions. I used this forum as a reference when I was looking up information on my search for a truck, but just joined to post my dilemma after finally purchasing the truck.

I just bought a 2016 Limited with 88,000 miles a 6'4" bed, ramboxes, air suspension, 3.55 ratio and aftermarket rims and tires (still 20" I believe, but slightly over-sized tires at 56lbs per tire). I live in Michigan and purchased the truck in South Dakota. We drove it back (about 772 miles) and on the final fill up we reset the trip odometer. The computer read 503 miles traveled when I filled up and I put 23.7 gallons in it (21.2 mpg), but with about 420+ miles or so of those miles being highway miles cruising between 73-75mph, I expected it to be much higher (the computer read an average of 22.3mpg after just the highway mileage). I can tell from the zip on my credit card statement that an actual 420 miles were driven on the highway from that fill up, but I don't know what that correlated to on my trip odometer.

I was thinking that I would be at at least 24-26mpg for this tank and then my typical driving would drop it to the 21-22mpg range, I am a little concerned because I purchased this truck specifically for the fuel efficiency. @hunter1234 has great results with a similar year and options, so I am quite intrigued at what the difference could be. I know it is really early so I will keep tracking, but wanted to get it out there.

I do want to get the GDE tune at some point, but I have the Mopar Max Coverage Warranty transferred to me for 2 more years, so I don't want to void that.

Any ideas. I am not overly mechanically inclined, but I want to do whatever is needed to get it up within reason.

Addition: I believe all the recalls have been completed on the truck (or at least they said they were being done last week) since they were "no sale recalls" for the dealership.
I finally took a long enough trip to get a decent idea of true highway mileage. In the first 262.5 miles I averaged a hand-calculated 20.7 mpg. The "Lie-O-Meter" read 20.5 mpg. It was mostly freeway driving at 69 miles per hour (more on that in a minute), with some two-lane, 45-55 mph driving thrown in. It also included a long idle (15 minutes more or less) in the McDonald's drive through, which I figure cost me up to 2 mpg. The second leg of the trip was similar in composition (without the McDonald's idle time). I have not filled it up yet to do the calculations by hand, but the dash reads 23.3 mpg. On one stretch the average got as high as 24 (on the dash). I drove it as easy as I knew how. I experimented with speeds between 67 and 70 mph on the freeway with the current mpg screen on the dash monitor, and it looked to me like each mile per hour difference in that range equated pretty closely to a 1 mpg difference. At 67 miles per hour, the meter was indicating 21-25 miles per gallon typically on more-or-less level terrain. At 68 mph it was 20-24; at 69 mph it was 19-23, and at 70 it was 18-22 mpg. Have not researched which rear-end the truck has. I had just the front rack on the back (no kayak) which does stick up just slightly above the cab, and the tonneau cover open on the first leg (262 miles) and closed on the return trip. I also have the Decked full-bed tool box system in the back that adds 300 pounds, empty, and I have some stuff in it, but probably not another 100 pounds worth. I had one adult passenger with me on the trip, with baggage for a weekender - not much. So the truck wasn't empty, but it wasn't particularly loaded, either. While I'm glad to finally break the 20mpg barrier, I'm still disappointed that we didn't at least break 25mpg. Like you, one of the reasons I bought the truck was because of the appealing fuel economy. I've talked to more than one Hemi owner who gets better mileage than I do.
 
21 - 40 of 48 Posts
Top