7.3IDI towing limit?

kc0stp

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Figuring you want to hold 65 (and preferbly run the AC...) what can a 7.3IDI run weight wise assuming a box type bumper pull trailer (car trailer to be exact)? Starting out with NA and moving on to turbo as $$ allow (and will probbly keep going power wise...)
 

Old Blue

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The question you are asking is very complex and time consuming to answer, but not overly difficult if broken down into small chunks. If you really want to know how to calculate this for our trucks, we can calculate it with a relative degree of confidence - but be prepared this is about an hour or two lesson in machine power physics. It is a lot to digest, but can be useful for a heavy cross country load or a regular hauler. I am all for people learning and if you want to I'll help you out, but if you just want some anecdotal stories, I'll have to defer to someone who has pulled a lot with their own setup(s). :D
 

snicklas

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I know this doesn't directly answer the question..... but one big thing to remember with all the IDI trucks, 83-94, N/A and Turbo. These trucks were designed in the days (Late 70's into the 80's) when the National Speed limit was 55 MPH. Most will agree these trucks work very well in the 55-60 MPH range, empty and towing, and get the best mileage. One "rule of thumb" I have heard with the IDI.... they will pull anything you N/A @ 45 MPH and Turbo 55 MPH. The newer trucks (99+ SuperDuty's, Cummins and Duramax) were designed when the National Speed Limit had been raised to 70 MPH. I know on my truck (2003 Excursion 4x4 6.0PSD) gets the best mileage on the interstate at ~70-72 MPH. The magic RPM for mileage and towing at a constant cruising speed is to keep the trucks under 2000RPM. This keeps them in the powerband, and helps to get the best economy. Most IDI's 2000 RPM is ~ 55 - 60 MPH, on my truck 2000 RPM is ~70 MPH. So, in this case, the reason the IDI's are happier at 55-60 and my truck at 70 is that is the speeds they were designed to operate. Just something to keep in mind.
 

Goofyexponent

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Three MAJOR factors to consider here. It all depends on your tire rating, door tag rating and your driving skills.

I have seen people drive a 5 ton truck hauling an excavator that I wouldn't let haul a pop up camper with a station wagon.

All in all, if you THINK you can haul it, you can. Safely and legally are two other matters. I have hauled some pretty wild things with the pickup. It did it just fine, but I wasn't legal OR on public roads.

Try THIS on for size.

When my truck had 4.10's in the rearend....I came across a loaded tractor trailer that had stalled and the starter was toast. I hooked a chain up, and dragged all 75000 pounds across a flat andupt to about 30 MPH before he popped the clutch and got her to fire up. 75000 pounds towed with a chain, and the truck was happy doing it. I wouldn't want to drag it up ANY kind of a hill, but I was impressed with it.
 

gonecrazyi

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55-65mph is where I sit towing. Usually 70 running empty. I've never found anything I couldn't move but have had to use. Lo lock a few times to get moving. But when I had the turbo i could cruise 70 no problem with a trailer. Stopping the load and my big tires does sometimes get hairy when people cut you off though.
 

GOOSE

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A 5.8 gasser with 4.10's and ZF was rated to tow 12,500 lbs on the bumper , 1991 cclb 4x4 if I remember correctly. I am aassuming that my idi with an ATS turbo can accomplish the same. There are many aspects that go into rating a truck; can they get to a safe merging speed in a certain distance, stopping, starting on grades, reversing on grades. I believe the standard for a merging lane is in the 600' arena. If you can only accomplish 35 mph in that length, you are a safety hazard. I read an article that went into great detail about this very matter, can't remember where, maybe Diesel Power??

I have tested the limits at 28,000 lbs gross wt. Yeah, I can do it, but not real well. Had to put T-case in low range to start on a grade, otherwise not too bad around town. Definitely would not try that on a highway though.
 

GOOSE

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Figuring you want to hold 65 (and preferbly run the AC...) what can a 7.3IDI run weight wise assuming a box type bumper pull trailer (car trailer to be exact)? Starting out with NA and moving on to turbo as $$ allow (and will probbly keep going power wise...)

On flat ground? I'd say 10,000lbs. In the mountains, she won't accomplish your requirements empty.LOL....with the turbo.;Really
 

NTOLERANCE

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I've pulled 12K from a receiver type hitch on the back of my 1993, NE, ZF5, 3.55 geared 2WD truck, and acesended a pretty steep grade more than once. I dont think I'd want to pull that much on a daily basis.
 

RLDSL

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If you are wanting to be able to hold 65 at your altitude, and assuming you dont spend your entire life in teh eastern part of your state, a bout 7000 lbs is about all you want to be dragging around at most , and you wont be keeping up 65 in the hills out there but at least you wont be crawling too bad.

Having spent some time out there a few years ago grossing 18k WITH a turbo , granted most of the flatland interstate criuising goes pretty steady around 62 mph in 4 over but those mountains could bring things to a steady crawl pretty quick , and that's with 15 gears to play with.
 
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