Detroit 14L Mileage

Razor, it does make a difference but its possible something else is wrong with your truck...Have you considered getting your truck tuned? That will bump the power up. Remember, Detroits like higher RPM's for better fuel economy. If you're water temp is that low, consider covering the radiator. That is the perfect cure. CAC leaks will kill your MPG's too. It does get better.

 

I drove a 2004 Freightliner Columbia with a 14L with an ultrashift for six months in 2010. I did a thread about increasing the mpg on here. The biggest suggestions had to do with driver habits. During one trip when it was cold but not freezing, I turned off my a/c, and was light on the gas. I also had 25K in the box and got 7.16 and 7.37 on fill ups doing 60-62mph. This truck was former trans-am and had 3:58 rears and the 10spd ultrashift.

 

I know the truck needs an overhead done, it has more than 800k miles and I havent done it since I bought it 250k miles ago, also it is a former big fleet truck so overhead was maybe never done. I just dont trust the mechanics, for every good tune up I hear about three that had gone wrong.
I am going to replace the CAC and possibly do the EGR delete, if the mileage doesn't improve in the summer I'll get overhead done.

 

I'd get your overhead done ASAP.

These valves get tighter not looser. As such, you could burn them when they get too tight.

By that, I mean you get NO valve clearance and they will be held open.

 

I get most of my Donaldson filters at Ryder Fleet Products online. I use the Donaldson extended life ELF3998 on my series 60. Ryder, generally, has decent pricing.

 

dude an overhead is less than $400. What are you waiting for??? Your out on the road and and you want to wait till summer to something that is 200k past due.....

 

How can you find out if the drivetrain can handle the extra HP and Torque?...currently I'm running 515hp 1650 torque on mine...but would love more torque...also my mpg's went up about 1 mpg with the EGR disabled, however as soon as temp got below 60 I lost 1 mpg...

 

drive it like you do now and it will handle the extra power fine drive like a retard parts will fly

 

The main thing is use the fuel pedal like there is an egg under it and keep it off the floor until you get within the top two or three gears if you have a 10 speed.