towing rpm's?
05-06-2007 | 11:22 AM
#16
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Joined: May 2002
Posts: 1,425
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From: Melbourne, Florida
We are full-timers and haul a 38' 5th wheel with a stock 2004 Dodge 3500 STL Cummins Turbo Quad Cab Dually with a LB and RWD and Auto Trans with 4.10 gearing. Since new we have put 70K miles on it without doing anything but keeping it properly serviced and changing those trans and rear-end fluids. The Goodyears that came on it lasted 45K miles and I now have Generals and they are doing a little better than the Goodyears did. The 2004 has a combined weight ratio of 26,400 lbs.. Our 5th wheel usually tops out at about 15K and we have another 3K in the truck including fuel and passengers so we are within 1K of max most of the time. The best RPM for fuel economy is about 2100 and that is about 67 MPH on the straight and level. The 4.10 will start costing you if you run much faster than that. When pulling 5.0 or higher grades I always drop it into tow-haul mode when the speed bleeds down to 60MPH or less and the RPM will go up to 2600-2700. With our load we can still pull a 7.5 grade at 45 - 50 MPH but the turbo will be screaming. With the 5th wheel in tow we have averaged between 9.5 - 11.5 depending on the number of grades we have to pull and the wind conditions. Empty at 70 MPH and 2200RPM we get about 15.5 MPG. When it starts to get lower than that it’s time to change those fuel filters.
FL_FullTimer
FL_FullTimer
You may have typed it incorrectly.
Dave
05-07-2007 | 09:50 AM
#17
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Joined: Aug 2006
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From: Riverside Ca.
I think he means 22,400lbs GCVWR.
I have the same 5er weight and gearing as him. I agree with almost everything FL Fulltimer said.
I'm pulling 14K, my 06' SRW MC weights 7500lbs ready to roll.So I have a GCWR of 22480 (CAT scaled).
On 5-6% grades It's all I can do to keep 35-40 mph, 2600-2900 rpms.
I have the same 5er weight and gearing as him. I agree with almost everything FL Fulltimer said.
I'm pulling 14K, my 06' SRW MC weights 7500lbs ready to roll.So I have a GCWR of 22480 (CAT scaled).
On 5-6% grades It's all I can do to keep 35-40 mph, 2600-2900 rpms.
05-07-2007 | 10:03 AM
#18
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Joined: Jan 2006
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From: Shelby NC
Pulled a 6% for 4 miles las thursday and got stuck behind a car going 45. After I passed him I was able to pull back up to 55 at the top. The next one was a 7% for 1 mile. Went into it at 70 and came out the top at 70. As long as I can hold 65-70 i can keep it. Once I drop to below 55 I cant regain much more than 55. The truck 5ver and passengers is around 20,000lbs.
05-07-2007 | 12:20 PM
#19
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Joined: May 2007
Posts: 258
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From: Idaho
Hey all - my first post!!
I have a 29' Springdale that's around 10k loaded and we have a nice 7% hill here that lasts for a few miles, and in Tow/Haul it won't go over 2k rpms and that puts me at about 50-55 mph. Do you think I have some problems? I know my tires and wheels will mess me up a little - I have Toyo Open Country A/T's 325/60/20's.
I have a 29' Springdale that's around 10k loaded and we have a nice 7% hill here that lasts for a few miles, and in Tow/Haul it won't go over 2k rpms and that puts me at about 50-55 mph. Do you think I have some problems? I know my tires and wheels will mess me up a little - I have Toyo Open Country A/T's 325/60/20's.
05-10-2007 | 11:32 PM
#22
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Joined: Jul 2002
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From: Post Falls, Idaho
I just got back from a pretty long trip from here down to eastern southern california....with some 'decent' hills between here and there....
here in Oregon, rolling in 6th around 65mph in the flats puts me just under 1800rpms...and dropping into 5th (direct) kicks me up to 2400-2500..
at around or just over 17k #'s combined weight, my truck will pull most any hill w/o problem if kept above....say 2000-2100 rpm in 5th (around 50mph)....
if I'm heavy, its a STEEP hill, or a hill w/ lots of curves that force me down under 50mph.....thats when I start thinking about 4th gear....
but, on the Interstates, I can usually pull most any hill in 5th gear....usually around 55mph...2200-2300rpms...
('01.5 HO, 6 speed, EZ, and 295/75-16's for reference)
here in Oregon, rolling in 6th around 65mph in the flats puts me just under 1800rpms...and dropping into 5th (direct) kicks me up to 2400-2500..
at around or just over 17k #'s combined weight, my truck will pull most any hill w/o problem if kept above....say 2000-2100 rpm in 5th (around 50mph)....
if I'm heavy, its a STEEP hill, or a hill w/ lots of curves that force me down under 50mph.....thats when I start thinking about 4th gear....
but, on the Interstates, I can usually pull most any hill in 5th gear....usually around 55mph...2200-2300rpms...
('01.5 HO, 6 speed, EZ, and 295/75-16's for reference)
05-11-2007 | 01:49 PM
#23
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Joined: Sep 2005
Posts: 75
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From: Arlington, WA
I know my tires and wheels will mess me up a little - I have Toyo Open Country A/T's 325/60/20's.
Stock tires 265/70/17?? should equal about 31" tire
New Tires 325/60/20 should equal about 35" or more tire
Equals a fuctional gear ratio of about 3.21...there's your problem.
Stock tires 265/70/17?? should equal about 31" tire
New Tires 325/60/20 should equal about 35" or more tire
Equals a fuctional gear ratio of about 3.21...there's your problem.
05-11-2007 | 04:42 PM
#24
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Joined: May 2002
Posts: 292
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From: Pike Road, Alabama
, i want to know what the optimum rpm's are pulling a 6% grade towing about 10k? rig w/toys is in the sig. thanks in advance.
Anyway, to answer your question. 10k would be about 17k GCW. At least that's what I assume you want to know. With my 6 speed, if I were pulling 6% grade with that load, I would pull it back to 5th and run ~2,400 rpm. That'll keep plenty of boost blowing as cool as a charge through the engine as possible. That should keep the EGT's down. And, in case you hit an even steeper portion, from 2,400 rpm to 2,100 rpm you'll have plenty of torque, and the boost will stay up. That's my $0.02 worth.
- JyRO
05-11-2007 | 10:44 PM
#25
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05-12-2007 | 12:07 AM
#26
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From: LAKEWOOD, CA
When loaded I'm at 22,000 combined (cat scale). I can pull the hills going North from Shasta into Oregon (6%?) above 65mph, in 3rd locked, at 2,700 - 2,800 rpm. I will hit 70 -72 mph which is getting me at redline. I don't think reving these things hurts them a bit. The truck is bone stock.
05-14-2007 | 02:46 PM
#27
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Joined: May 2007
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From: Idaho
Tonyiii1 - thanks!!! I kinda figured that was my biggest problem -
I pulled the same hill again this weekend, and took it out of D into 2 and the rpm's went to about 2700 - pulled the hill great - same speed as before, but I could accellerate and the engine wasn't working as hard either...
I guess there's a price to pay to look cool...
I pulled the same hill again this weekend, and took it out of D into 2 and the rpm's went to about 2700 - pulled the hill great - same speed as before, but I could accellerate and the engine wasn't working as hard either...
I guess there's a price to pay to look cool...
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