A lot of great info on here guys....I'm new to the site here, but have a little info that really has helped my MPGs also. Warm the engine before you move. I thought it was bogus info for the summer months, but has really turned out to be on the money...Wait till the "needle" starts to climb before driving. Can really make a difference, not to mention gets the engine full of lube before you start raising the RPMs

 

Welcome to FTE...BUT...This is exactly wrong...no disrespect intended. When you idle a vehicle, what mpg are you getting during the whole warm-up process? Exactly ZERO MPG. The engine IS "full of lube" once the engine starts...The idea is to drive it gently until it warms up, but to idle is to waste fuel and lower overall mpg. Getting a diesel engine up to operating temperature as quickly as possible is a key to good mpg and you do that by driving the vehicle, not idling it.

 

Make sure your brakes aren't hanging up or dragging. These trucks are notorious for the calipers sticking.

 

The OP simply asked for ideas on where to look for mileage improvements, lift kits do affect the aerodynamic resistance of the truck bu changing the air flow pattern under the chassis, aggressive tread patterns have a higher resistance to roll as indicated on the side wall, hot air is less dense as proven by the laws of physics! These improvements will not nesseceraly be concurant but cumulative, and will provide increaseses for the majority, will I be doing any of them no I'm happy with my 16/17mpg

 

Trey what condition are your injectors in?

 

Bad MAP sensor. A couple of years ago there was a long thread about how a bad MAP sensor will lower mileage considerably.

 

Good catch Scott...wasn't there something about cleaning out the EPBV tube and MPG?

 

I am surprised #5 includes the HPOP reservoir. I thought that was accepted as unnecessary.

 

No idea. But I've never had any symptoms to suggest they need any attention.

I am unfamiliar with MAP sensor. Can you please tell me what it stands for, what it does, how it works, etc?

Yes. I did notice an increase in MPG when I cleaned out my EBP Sensor and tubing.

Ditto. I also thought that was considered unnecessary. Jody has spoken!

Would THIS be the procedure to fix that?

Thanks. I have read that document before, and follow all the suggestions. Even reinstalled my airdam.

I now realize that 4lbs is normal at cruising speeds. Yesterday I pulled my IC tubes and boots, cleaned everything thoroughly, and reinstalled today. The majority of my boost leak is gone! I can now produce 25lbs of boost easily (and by that I mean putting the pedal down), where as before I could push 15lbs and be worried my turbo was going to blow up because of how loud it was.

Currently I hop between 80t and 80e on my DP Tuner as required for work. My 13MPG is averaged tank to tank. The tuner is not to blame, it can only work with what its given and if something is broken it cant fix it. My MPGs sucked before the tuner, and the tuner didnt change that, but it added MUCH more power. So I gained power and no change to MPGs. I guess that could translate into improved economy.

 

I brought this up on some of the other threads. But i had very dirty leaky looking intercooler boots. A local shop removed,cleaned and reinstalled. Seemed to raise my mpg back up to its normal. Seemed to me i gained 2to 3mpg back.

 

I can't believe nobody mentioned gear ratio's. you could be "pushing plywood through wind" with your big truck. You lifted it, added bigger tires. Now your engine is "struggling" to keep up speed. If you started with 3.73's you would need to go to like 4.11's to keep everything in prospective.
When I was building Ford "streetable" rock crawlers. I was using 5.89's. Couldn't go fast, but the engine never struggled and got great mpg's with 42's
This isn't a bash on your lift kit and big tires. Its just an observation that nobody including you mentioned your gear ratio's. My 91 IDI 7.3 "bread Van" got 14mpg and it had 5.14's Talking about pushing plywood through the air.

 

My gear ratio is 3.73. My current tires are 305/70/16, which equals 32.8" according to
Metric To Inches Tire Size Conversion

According to Tire Size Calculator - tire & wheel plus sizing
The factory size was 235/85/16 which equals 31.7".

What would be my optimum gear ratio? I am not good with gear ratio stuff... So help me out here. Going to an "Optimum gear ratio" such as 4.11 or 4.27 should put my MPGs in line? Will it hurt off road capabilities or affect towing?

 

I have a 6" lift and all terrains and get around 17mpg on 80e

 

i have no lift 285-75-16 on 3.73 with mods in sig and i only get 16 mpg so i dont know what to teal you. and i got only 15 with the stock air box?

 

I also have my 6637 under the hood, no air box, but i cut holes in the front so it feeds more fresh air at high speed. the bottom of the battery box is still mounted, with the front air feeder box tube, but there's no cap on the box.

my 80e shifts into 4th early too so i can cruise around town in 4th gear @ 41mph