RAM 1500 Diesel Forum banner

1 - 20 of 41 Posts

·
Registered
Joined
·
693 Posts
Discussion Starter #1 (Edited)
Laramie Crew Cab, 2WD, 1290 capacity per door sticker. 24' enclosed trailer, ~7200lbs. Tongue weight ~800lbs. Conventional spring suspension assisted by Airlift 1000 airbags (rear).

http://i465.photobucket.com/albums/rr17/RangerGress/Ram/RamTrailer_zps9c51ce73.jpg

http://i465.photobucket.com/albums/rr17/RangerGress/Ram/Airlift1000_zps57777b30.jpg

Rear end sag.
Height from fender to wheel, inches.
Unloaded, Rear 12 5/8, Front 10 11/16
Trailer hitched up, Rear 9 5/16, Front 11 9/16
Put 40psi in airbags, trailer still on Rear 11 1/2, Front 10 5/8
Took trailer off, 40psi, Rear 12 7/8, Front 10 3/4
Trailer back on, hitch "tilted" forward 2", weight distro bars on, Rear 11 5/8, Front 10 7/8
http://i465.photobucket.com/albums/rr17/RangerGress/Ram/WeightDistroHitch_zpse4387eab.jpg

I'm working on moving the hitch ball 2" closer to the reciever. This shortens the lever arm the trailer has to move the truck around. This is significant both for truck F/R weighting also for sway. Moving the ball 2" closer means moving the hitch 2" deeper into the hitch receiver. This requires drilling a 5/8" hole in the solid steel hitch for the hitch receiver pin. I spent a bunch of time on this today but all I did was learn that Harbor Freight drill bits are only fine until you come up against solid steel. I got about halfway thru before my drill bit was useless so I'll have to buy some better drill bits and work on that later in the week.

Lessons learned

-800lbs drops rear end 3+ inches and raises front almost an inch. That's a lot.

-40psi airbags changed droop significantly. Rear goes up almost 2". Front down about an inch.

-With no trailer, 40psi airbags don't change ride height much.

-Moving the hitch forward (towards truck) 2" and putting on weight distro bars pretty darn tight changed ride height by only ~1/8". Therefore weight distro bars don't effectively counter rear sag. Note tho that weight distro bars shift do more weight when the rig porpoises so they still fight that pretty well..

-Towing mpg. Went for a 25mi test tow on a flat freeway at 64mph. 14.1mpg. For perspective, my 2000 F-250 diesel would have gotten 13-13.5. My old 2006 F-150 5.4l would have gotten 7mpg.

Lessons learned. I had hoped to get an honest 15-16mpg so this was disappointing. The diesel in the F-250 is regarded as one of the finest diesel engines ever put into a pickup and clearly it's a hard standard to beat. Gas engines suck towing heavy loads. It looks like I ended up with a very comfortable truck that gets great mileage when used as a DD, but isn't much of an improvement towing my trailer.

Towing heat issues. It was 85deg ambient during the above test. Both my coolant and oil got pretty darn hot. Coolant 224deg, oil 237deg. I did not expect this because 64mph on flat terrain didn't seem to stress the engine at all. It's the coolant temp that got my attention. I think I'm going to reduce the concentration of anti-freeze from 50% to 25%, and see how I might optimize air flow for the radiator. Antifreeze has lousy heat xfer specs, so you don't want to use any more of it then you need to. In Savannah, GA it only barely hits freezing a couple times/yr so 50/50 antifreeze is way overkill.

I also want to check if the radiator is adequately shrouded,and I might get a different grill. Radiator shrouds ensure that all air that hits the grill has no choice but to go thru the radiator. The blingly Laramie grill looks it might be blocking a fair amount of air.

Misc. Engine has all sorts of power. Just wish it had all sorts of cooling. Trailer brake controller works well. Since the freeway was flat, I did not engage Tow Mode.
 

·
Registered
Joined
·
84 Posts
I wonder is there is a way to keep the grill shutters open all the time. I wonder it that would help as will.
 

·
Registered
Joined
·
274 Posts
Antifreeze also contains the corrosion inhibitors. If you're going to take some out then you need to add back the corrosion inhibitors. I use Amsoil coolant boost and it aside from containing inhibitors it's lowered my coolant temps 15-20* when towing heavy over the hills with my F250.

Well on second thought looking at your numbers they are higher than most other 1/2tons but still within operating range. Engines perform better at higher temps the coolant doesn't boil until ~250* and oil is good past 300*. Those numbers may seem high but that simply could the the normal operating range for this truck to get full MPGs out of it. I would leave it as is and take it to the first event and monitor it.
 

·
Registered
Joined
·
693 Posts
Discussion Starter #4
Antifreeze also contains the corrosion inhibitors. If you're going to take some out then you need to add back the corrosion inhibitors. I use Amsoil coolant boost and it aside from containing inhibitors it's lowered my coolant temps 15-20* when towing heavy over the hills with my F250.

Well on second thought looking at your numbers they are higher than most other 1/2tons but still within operating range. Engines perform better at higher temps the coolant doesn't boil until ~250* and oil is good past 300*. Those numbers may seem high but that simply could the the normal operating range for this truck to get full MPGs out of it. I would leave it as is and take it to the first event and monitor it.
AMSOIL Coolant Boost is a wetting agent like WaterWetter. They both also contain corrosion inhibiters. They will be helpful when used with pure water, but less help when used with antifreeze. This is because anti-freeze already has wetting properties and anti-corrosion. I could just drain all the coolant out and put in WaterWetter and be done with it. Then next Dec I could just put in a bit of anti-freeze so I don't have to worry about a sudden cold spell.
 

·
Registered
Joined
·
1,337 Posts
Big mistake not useing tow mode! Am I the only one who picked up on this?? Use it next time and you WILL get better milage and I would be willing to bet lower temps! That's I good size load you got hooked up there, doesnt really make sense not to.....
 
  • Like
Reactions: gleb

·
Registered
Joined
·
438 Posts
I would not worry about the temps. All new vehicles run hot for emissions and MPG. My wife's 2012 Grand Cherokee Pentastar V6 ran 216F-220F last year on a long road trip out west. The oil stayed at 195F-200F. That was with a family of four running 80ish mph on the flat parts I90 in South Dakota.
 

·
Registered
Joined
·
274 Posts
The point of adding it is because all the additives are balanced at their required amounts in a 50/50 water coolant mix, most allot for 40-60% coolant and being within spec. If you go below 50% coolant and especially 40% you're loosing the minimum corrosion inhibitors required so you'd need to supplement them with something like water wetter or Amsoil.

I used water wetter for years on the race engines since glycol is banned in all the racing I do, works fine but didn't provide the coolant temp drop like the Amsoil does. Both advertise lower coolant temps because they are surfactants and lower the water tension allowing for the coolant to reach deeper places or something like that however Amsoil was the only one that I actually noticed it. Either will suffice for the anti- corrosion needs.

If for whatever reason you do decide to drain the coolant and go with straight water get the Amsoil. When used in pure water systems it's actually recommend to use tap water. On all the race bikes and cars yearly changes are as simple as draining, flushing and filling up, all with the water hose.
 

·
Registered
Joined
·
693 Posts
Discussion Starter #8
Big mistake not useing tow mode! Am I the only one who picked up on this?? Use it next time and you WILL get better milage and I would be willing to bet lower temps! That's I good size load you got hooked up there, doesnt really make sense not to.....
My perception is the time to use Tow Mode is when the tranny is doing a lot of shifting. Since it was a flat run, there was no shifting. I don't think Tow Mode would have made any difference.
 

·
Registered
Joined
·
274 Posts
Tow mode does matter. It locks up the torque converter later so the engine has less load on it. When loading the engine whether accelerating, going up hill, or going into the wind(head wind or the 65mph one from simply driving) the engine is under load. Normally the engine will stay in gear and power through it because it's a light load. If hauling/towing in tow mode the ECM knows you're hauling/towing and changes the TCM strategy to downshift providing more horsepower and faster flowing exhaust gases. If it stays in a higher gear and doesn't downshift to 7th or 6th it will build up EGTs causing the coolant/oil temps to rise and dump more fuel loading the engine in a higher gear when it should downshift.
 

·
Registered
Joined
·
1,337 Posts
Try it you will see.... I have towed a boat and a utility trailer so far nothing near as heavy as what you were towing mind you but it got my better mpg's on the way back with the boat by almost 1.5mpg, I couldn't tell you why it just did.... they put it there for a reason...
 

·
Registered
Joined
·
1,518 Posts
..........

Towing mpg. Went for a 25mi test tow on a flat freeway at 64mph. 14.1mpg. For perspective, my 2000 F-250 diesel would have gotten 13-13.5. My old 2006 F-150 5.4l would have gotten 7mpg.

....... I did not engage Tow Mode.


Well.... to me... it doesn't seem that bad. (yet)

First... we have to compare "apples to apples". So, this truck was meant to compete with a 1/2ton gas V-8. AND, in doing so... you DOUBLLED your mpg's. (more or less) In that respect... I think it did good.

Also this truck isn't a HD version. So... you really can't compare it to the 3/4 ton Diesel. Lets face it... putting 7000Lbs behind a 2500/3500 is nothing, and you really aren't even stressing it. If you think about the comparison as a duty cycle... the 2500 would only be around 50%, and your ED 1500 would be very close to 95%~100%. At that point, you would expect efficiency to fall off. One thing I tried to tell my dad when he bought his new truck is... "Just because it can tow 8000 Lbs, doesn't mean you really want to plan on towing that much." (he bought a new travel-trailer) My general rule is... if I need help with load leveling... then I need a 2500. (lets face it, the load distributor, and air bags are a Band-Aid for something that isn't strong enough)

Right now, my "Heavy" trailer is under 5500 Lbs. If I was planning on towing more than that... I would have bought a 2500.
Not trying to sound negative... just giving my thoughts.

As commented on above... not using tow mode was a mistake. This isn't like the old days where it would basically just turn off the OD. Putting the truck into tow mode changes EVERYTHING about the truck. It turns on the anti-sway... it changes the shift logic to help with acceleration, and decal... it changes the power steering (neat feature with the electric PS)... and I'm sure it will make sure the shutters stay open to help the cooling.


As a final thought... These trucks run hot. As said above... it's normal now. AND... you will see the trans and oil running at the same temps as the coolant, since the "coolers" are really just heat exchangers. So, even when unloaded... you will see 200 degree trans, and 190 degree oil temps. As far as changing the ratios, or mixing in other products.... I don't recommend it. The new coolants are strange, and I don't think there is enough knowledge on them (to the public) yet. Personally... if there is a question... I would drain and flush the system, and just put in good old glycol based stuff. (they just stopped using it because the Green'ies don't like it)

Try it again with the tow mode active, and let us know what happens.

Just my random thoughts.
 

·
Registered
Joined
·
693 Posts
Discussion Starter #12 (Edited)
My F-250 did DD duty several days per week on average and got 12-13mpg doing it. Compared to that the Ecodiesel is a huge win, both in terms of fuel efficiency and being an oasis of peace and comfort. But there were some reviews written last year that indicated I would expect 25-30% better towing mpg, so I was looking forward to that. Monthly I go tow 12-16hrs round trip so towing mpg is a big deal.

Compared to the F-250 getting 12-13mpg driving to/from work, this morning I got 28mpg. Admittedly I drove it gently because I was watching the mpg display. I'm going to save a ton of $$ on diesel.

I'll try tow mode next time and see what happens. I'm dubious re. the mpg advantage on flat surfaces tho. Nothing anyone mentioned here re. tow mode would have made any difference on a flat freeway. I don't buy that there is drivetrain efficiency left on the table for me to grab at a push of the button. The torque convertor is already going to be locked up at freeway speeds, you can't make it more locked. The radiator louvers are going to react to coolant temp, not the tow button. Also, I don't think the tow mode turns on anti-sway. I think it's always on unless you turn off all stability control.

Re. radiator cooling. I'm driving on with my idea of going to a 25% solution. Women are complicated, but thermodynamics, heat xfer, chemistry and engine cooling are all pretty straight forward.

Re. 2500 for a load this heavy. My objective was to walk away from my 3/4ton and make a 1/2ton work so a 2500 wasn't an option. That is to say, if the objective is "don't buy a 2500", the list of solutions can't include "buy a 2500." In terms of suspension and frame strength, I'm sure I'll be fine. Both for load and towing I'm under the spec for both. If I had air suspension it would do the leveling for me. What I'm doing with the Airlift 1000 kit isn't that different.

Re. coolers being heat exchangers and will therefore run near coolant temp. I didn't understand that. Everything heat oriented about the 3 systems is different. The only thing that's similar is that they have designed operating temp ranges in the same ballpark.
 

·
Registered
Joined
·
2,320 Posts
I Seeing stuff like this, I am considering a 2500 CTD for my Travel Trailer.

Sent from my SCH-I605 using Tapatalk
 

·
Registered
Joined
·
241 Posts
Milage I think that you did do 25 to 35 percent better with your milage compared to the half ton that you were getting 7mpg's and I never saw where they compared this truck to 3/4 only 1/2 and it is a world beater in this segment.

You state that you were on the flat interstate but how did you get up to speed and how much fuel did it take to get there because you did not have it in the tow haul mode and change the shifting as the software in the truck is designed to do.

Everyone mentions that the shutters being opened but what does it do to when the fan is kicking on in the tow haul mode. Your little truck is doing a good job with a big truck haul.

I just love it when we want to haul 3/4 ton truck loads with our 1/2 and then are not sure why we are not getting 3/4 results.
 

·
Registered
Joined
·
693 Posts
Discussion Starter #15
Milage I think that you did do 25 to 35 percent better with your milage compared to the half ton that you were getting 7mpg's and I never saw where they compared this truck to 3/4 only 1/2 and it is a world beater in this segment.

You state that you were on the flat interstate but how did you get up to speed and how much fuel did it take to get there because you did not have it in the tow haul mode and change the shifting as the software in the truck is designed to do.

Everyone mentions that the shutters being opened but what does it do to when the fan is kicking on in the tow haul mode. Your little truck is doing a good job with a big truck haul.

I just love it when we want to haul 3/4 ton truck loads with our 1/2 and then are not sure why we are not getting 3/4 results.
I didn't start the trip computer until I was up to speed.

Comparison with 2500 http://www.ram1500diesel.com/forum/ram-1500-diesel-towing-hauling/238-ecodiesel-30%-better-mpg-then-ram-2500-pulling-7k-lbs.html

The radiator fan doesn't play >25mph or so. Your fan's responsibility is move air when you are not moving.

Re. "I just love it when we want to haul." Nice. I will sit on my hands and resist the temptation to be as snide. The idea of a more modern and smaller engine being able to more efficiently deliver the ~140ftlbs I need to pull my trailer on flat terrain at 64mph, then a 2.5x larger 20yr old design is not unreasonable. The question becomes has technology marched efficiency forward faster than the EPA has restricted it?
 

·
Registered
Joined
·
641 Posts
Don't mean to hi-jack this thread, but i was searching for answers on rear end sag (be nice) and thought the contributors above may be able to help. I have a ED CC Laramie 4x4 on order and I was considering calling the dealer to add air suspension option . I have spent the last couple of hours reading about issues/failures with the RAM air suspension in cold weather conditions (I live in Canada), and I am having my doubts. From what I have read the RAM rear coil springs are pretty soft, can anyone tell me what type of sag I can expect towing 5000-6000lb boat/dual axle trailer with a guess-ta-mate tongue weight of about 500lbs?

Thanks

Scott
 

·
Registered
Joined
·
1,337 Posts
Get a few thousand miles on the her and try tow haul mode and I think you will be quite happy, it's only going to get better.... motor is still basically brand new!
 

·
Registered
Joined
·
1,337 Posts
If you can still get the air, go for it the ride is amazing!! I had almost 1500 pounds in the back of top soil and the truck still levelled. There have been some horror stories but what you don't hear is the 10's of thousands of guys who have had zero issues whatsoever... it's a good closed system....
 

·
Registered
Joined
·
1,337 Posts
I am hoping mine performs well I have an about 9000# load I need to tow 450Km up to my farm the end of may. ( 16 foot dual axel trailer with a tractor and 2 quads)
 

·
Registered
Joined
·
214 Posts
If I can't overload this truck 2-3 times a month and drive 30-40 miles, I'll be selling and buying a
Tundra like I've had for 5.5 years. I've towed 10-11k lbs. put a pallet of mortar mix weighing 3000 lbs. hauls
Are short and I have air bags now. I ordered an outdoorsman ED with air-suspension to take the place of the Tundra.
I am pretty sure it will perform fine. I just don't want to drive a hunk of lead for the few times I need a 3/4 ton.
I have driven and owned 3 Powerstrokes mileage 30-50k per year. The truck is going to work.
 
1 - 20 of 41 Posts
Top