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hppyfngy
11-04-2013, 09:52 PM
I often use my '03 to tow my small Casita Camper. Weighs about 2500 pounds.

This van is pretty new to me, I've had it less than a year but as I tow up and down mountains, I was wondering what RPM range I should be seeking out for both mileage and life of the engine.

This is my first diesel, so I'm not really sure. The auto trans seems to keep things in line, but I do downshift regularly if climbing.

Any tips?

Randy

Aqua Puttana
11-04-2013, 10:31 PM
Some people recommend a ScangaugeII or other performance monitor unit. I don't have one.

The boat I tow is similar weight all up as what you mention. I shift down when I know a climb is ahead. I also will downshift at other times based upon my direct read mechanical boost pressure gauge.

I once thought that the transmission needed more help deciding when to shift when I was towing. Since then I now think that it needs help less frequently. That said, don't be afraid to downshift when it feels right.

A search here will likely get you some more towing information. vic

P.S. - I loved those little Casita campers. My wife loved the Jayco 23b. We now own a 23b.

sailquik
11-05-2013, 12:20 AM
hppyfngy,
Look up the horsepower and torque specs for your 2003 OM-612 2.7 liter 5 cylinder Sprinter.
If I recall correctly, the max. torque is @ ~2400 RPM.
The max horsepower is up around ~3250 RPM.
So, when pulling up a hill, I found that my 2006 3500 (with a whole lot more trailer behind it....~4,500 lbs) got the best mileage and ran coolest in the 2700-3000 RPM range.
You can run less RPM, but if you had a Scan Gauge II (or similar) you would see that the % engine Load, MAP (boost) pressure, and fueling rate are very high when you try to pull @ reduced RPM.
You have significantly less weight behind, with your Casita, but whatever RPM gives you the best mileage will be where you need to run, and having a Scan Gauge II (or similar) will help you dial that right in.
It's a nice smooth little engine, and it's pretty hard to tell when it working hard. MB put no gauges in to give you information on how hard it's working (beyond the temp gauge) so something additional really helps.
Roger

hppyfngy
11-05-2013, 12:31 AM
Looks like more headroom in the Sprinter than the Casita. Is that just the camera angle?

The Sprinter is taller and longer than the Casita. That's not an optical illusion. But the floor is lower to the ground in the Casita.

I'm 6'1" and can stand up fully in both, in fact it's almost identical now that I think about it.
I can't stand up nice and straight in either, without my head just touching the ceiling.

sailquik, I'll look into a Scan Guage. I'm not trying to nerd out completely on this though, a rough idea is probably enough to satisfy me.

But your numbers sound exactly right to me. When I'm climbing, it feels best between about 2500 and 3000 rpm. It really has no problems pulling this little trailer, I just want to be good to it. :thumbup:

SullyVan
11-05-2013, 12:42 PM
hppyfngy,
Look up the horsepower and torque specs for your 2003 OM-612 2.7 liter 5 cylinder Sprinter.
If I recall correctly, the max. torque is @ ~2400 RPM.
The max horsepower is up around ~3250 RPM.
So, when pulling up a hill, I found that my 2006 3500 (with a whole lot more trailer behind it....~4,500 lbs) got the best mileage and ran coolest in the 2700-3000 RPM range.
You can run less RPM, but if you had a Scan Gauge II (or similar) you would see that the % engine Load, MAP (boost) pressure, and fueling rate are very high when you try to pull @ reduced RPM.
You have significantly less weight behind, with your Casita, but whatever RPM gives you the best mileage will be where you need to run, and having a Scan Gauge II (or similar) will help you dial that right in.
It's a nice smooth little engine, and it's pretty hard to tell when it working hard. MB put no gauges in to give you information on how hard it's working (beyond the temp gauge) so something additional really helps.
Roger

What a great response! And to think I was just going to post, "mine does best at 2800rpm" ha ha ha

Most diesel engines have a sweet spot you can feel and hear if you just tune in.

surlyoldbill
11-05-2013, 04:02 PM
I have to add my personal observation that I get the most "oomph" around 2800-3000rpm.
I've always been told that "lugging" the motor at lower rpm is bad for it, and when I am under load, when the van has a hard time accelerating easily, I use the gears to keep it between 2500-3000rpm.

hppyfngy
11-05-2013, 05:11 PM
Agreed, Bill. If you punch it and don't accelerate quickly, you're lugging it and that's not good for the engine.

So all these answers confirm my feelings about where it likes to live. Mine is between 2500 and 3k when climbing or trying to accelerate hard.

The auto trans does a very good job, but I'll shift preemptively to help things along.

Aqua Puttana
02-23-2014, 12:47 PM
My :2cents:

I recently towed my sailboat from Niagara Falls to New Orleans and then to Daytona FL. My guess is that the rig weighs about 3000# all up. Single axle trailer. Michelin Marathon radials inflated to 55 psi cold. The Sprinter was loaded with vacation stuff, so maybe medium load.

At first I ran the CSS Ciprian Set Sixty method. I calcuated 17 mpg. I also found that I was shifting down to 4th gear fairly often.

As always seems to happen on long trips I found my speed creeping up. 70 mph Interstate limit. I found that as Roger, Surly Old Bill, and others have mentioned, the drivetrain seemd happiest around 2800 to maybe 2900 rpm. I observed that my rig climbed most inclines without any need to drop to 4th gear and just seemed happier. My mechanical boost gauge often hung in at 18 -20 psi on those climbs, but all seemed fine.

I did take a hit down to 14.5 or 15 mpg or so, but with higher speed that isn't unexpected.

The entire drive train response seemed happier at the higher road speed in 5th gear at 2800 rpm. Not so much when at 2800 rpm and in 4th gear.

As an aside, I dropped the rear tires from a normal of 65 psi down to 60 psi to see if the ride improved. I did notice a slight improvement in ride, but I noticed a distinct increase in the rig tending to wander. I went back to 65 psi and the expected "normal" good tracking returned.

Before anyone suggests it, "No" I am not going to purchase a performance monitoring device. I'm doing just fine now using my boost gauge.

Added edit.
There are already plenty of testimonial threads for ScangaugeII, Ultragauge, etc. on this forum. Let's keep this one on track for towing please.
vic

TurnOne
02-23-2014, 01:52 PM
For under a $100 and an hour of your time you can buy and install an Ultra-Gauge. Calibrate mileage using mile markers on the highway (I actually stopped to get the most accurate reading of them 3 miles apart) then fuel usage by filling the tank of fuel, drive around and burn a few gallons, go back to the same pump, fill up again and calibrate how much fuel you actually consumed. From the factory, the UG reads lower than real mph as measured by GPS. GPS also different than my speedometer. After that you can set it to display real time mpg. You can also look at engine load, boost pressure, coolant temp, voltage, and my other favorite, average fuel economy. You can see many other things, gallons per hour of fuel seems popular, but real time MPG is easiest for me to decipher. My 02 140 tall passenger seems to like 2500-3000 rpm best.

When you look at real time MPG you can figure out if the conditions are better to go 60, 65 or even closer to 70. Very best mileage will likely be around 45-55 mph. But I can't drive that slow on the hwy.

Chris

Aqua Puttana
02-23-2014, 02:08 PM
Thanks for the input.

"Before anyone suggests it, "No" I am not going to purchase a performance monitoring device. I'm doing just fine now using my boost gauge."

There are already plenty of testimonial threads for ScangaugeII, Ultragauge, etc. on this forum. Let's keep this thread on track for towing please.

vic

sailquik
02-23-2014, 02:27 PM
Aw Vic,
Let me see here.....towing does add significantly to the % engine Load our Sprinter's engine management systems must deal with.
While there are not legal issues and safety concerns (except to your engine and transmission) like trailer lights and brakes, the aftermarket performance gauge package (Scan Gauge II/Ultra Gauge EM/Dash DAQ/Torque with a dongle....etc.) does provide a Sprinter driver that is towing anything, or heavily loaded in the cargo compartment, with a window into what the engine management is doing for you.
It absolutely opens a driver/engine management link that is not otherwise provided.
So, IMHO it's the first thing that anyone towing more than a tiny utility trailer needs to invest in.
With no window to watch engine management, you are in for a big surprise the first time you tow anything and then refuel and
calculate your mileage.
I sure was.....blithely running across I-64 in the flatlands east of Rocky Mt. NC @ 70+ mph with 4,500+ 7 foot wide very tall cargo
trailer behind my '06 T1N 3500. Mileage went from normal ~20-21 down to 12.5 mpg. That was a shock.
With the Scan Gauge II watching LOD and GPH I was able to slow down a bit and bring the mileage back up to ~16.5 mpg.
No one I know wants to needlessly waste that much diesel fuel.
Roger

Aqua Puttana
02-23-2014, 06:10 PM
Aw Vic,
...With no window to watch engine management, you are in for a big surprise the first time you tow anything and then refuel and calculate your mileage.
...Roger
Golly Roger,
But I don't necessarily buy into your taken to the extremes high revs for fuel economy helping with the longevity of the Sprinter engine service. Higher engine rpm's = more revolving cycles = higher rpm at the transmission input shaft = greater wear = ?????

We don't need to go into discussion again of owner miles accumulated on a single Sprinter. The high revs being good over the long haul is a theory at this time.

I believe that for my sailboat rig I have found a sweet spot for engine operation and good transmission gearing range at the 2800 rpm range.
I'm not surprised by the resulting mpg. I'm OK with it.

vic