EZ Dodge Cummins Questions

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jeeper

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Good morning,

I am asking around on a few forums about a "new truck" that I am getting.

It is a 1989 Dodge 4x4 standard cab Cummins with a 5-speed.

My main intention is to use it for towing and hauling and occasional daily driving duty.

Assuming that I drive normal, 60 or under around here, what is a reasonable MPG to expect empty? Loaded with a 6k load on a trailer?

Best mods for mileage etc?

Also, I will likely limit any mods to exhaust and intake. I am most interested in keeping the mileage up. Not worried about racing it!

Thank you for any help.

ROB
 
Hi Rob.
Well.... its all subjective. Depending on how the vehicle has been treated and such. In its day the 6BT Cummins 12 valve was a good diesel engine. Reports of fuel mileage ranked anywhere from 20-28 mpg. When towing the mpg obviously dropped but alot were still seeing 15-18 mpg. The old Cummins was not a hot rod. Its actually rather soft when you put the steam to it, but it will get the job done... just not quickly. The simple upgrades that help the performance are simply done by opening up the exhaust system and a better air intake system. Spending money on injectors and all the other hoopla isnt going to gain you much for the bucks you will spend...other then create alot of black smoke. Another great thing to do on these it take them into a injection shop (preferably a diesel shop) there are tricks that can be done with the injection and timing that are merely adjustments that will significantly increase the power and make these diesels run alot better. Keep in mind 89 was the first year in the Dodge. If the truck is a manual trans, there may be some issues with the trans (if they have not already be addressed) and the other thing is the front suspension were soft and may need some work done on it.

Thats the basics and the knowledge I have. Hope it gives some insight.

-RPM
 
I had an 89 5 speed when they first came out, one of only 2 new vehicles I've ever bought. Mine was 2wd though. Mods I made were, removed the muffler and installed a straight pipe, it wasn't that loud especially inside the truck. Next I advanced the pump timing to 1.30mm and upped the rev limiter to 3100 rpms. I could get 26 MPG towing an open trailer with a car on it doing 95 MPH on the highway.
 
my 95 4x4 auto with Cummins gets 19 mpg driving 25 miles to & from work Set cruise at 60 mph

Mine as some exhaust work, timing up to 16 deg and pump tweeked. Yeah is lays down some smoke, but sure runs good. I did it for pulling not a race truck.

pulling my 24' enclosed car hauler at 75 to 80 mph gets 11 to 12 mpg, pulling 12' enclosed trailer 13 to 14 mpg

I have never pulled an open trailer any distance with the diesel, my open trailer has expanded metal gate and it is a sail and made my ramcharger drop 3 mpg, loaded 69 Coronet 500 convertible and removed gate and mileage went back to the 12 mpg I got without the trailer
 
http://www.dieseltruckresource.com/dev/index.php
http://www.cumminsforum.com/
http://www.dodgetrucks.org/forums/index.php
http://www.dieselbombers.com/
http://www.dieselram.com/
http://www.turbodieselregister.com/forums/

Here are a few forums to look at. The DTR has a great tech section, and it's free. You have what Dodge guys refer to as a First Gen truck, 1972-1993.
I have a 93 D350 dually, Cummins 5 speed, it gets 21 on the highway empty. Mileage goes down a bit the more in town driving that you do.
If yours is an 89, it won't have the intercooler, one could be added for a bit more power.
Watch the front end, it's loaded pretty heavy with the Cummins up front. keep an eye on the frame where the steering box bolts on, even 1/2 tons have been known to crack around the bolt holes. A little quality welding and a bit of plate reinforcement fixed mine. Borgeson joints to replace the factory
pot coupler on the steering column are a good improvement on these trucks too. Good luck with it!
 
Awesome news. I ended up getting it. My twin truck that I already had is the same color and year etc. It sounds like I can pull twice the mileage out of it. The efi 360 in my current work truck gets 8ish towing and maybe 10-11 empty. It is just not practical to drive much. I should ad that I live 20 miles from work approximately, and 50 to a town of any size. So it gets pretty spendy in a hurry to tow much etc.

I will look over the websites etc. and check them out.

Thank you, ROB
 
Check out www.tdr.com - good site, tons of info only "bad" side is dues I think $35/yr.
Check into the "killer dowel pin" on these trucks, TDR has tons of info on this - preventing the problem only costs a few $$$ and a couple hours, if it drops out it is a HUGE repair bill!

Good luck, the Cummins is a hell of a motor!
 
I started it up today and it is pretty cool. It is a fixer, but I got a great deal so I can fix it up a bit.

I will get on it more completely once I get a few other things under control.

Thanks, ROB
 
jeeper said:
I started it up today and it is pretty cool. It is a fixer, but I got a great deal so I can fix it up a bit.

I will get on it more completely once I get a few other things under control.

Thanks, ROB
Click to expand...


Use quality oil and filters on it!
 
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