There are a lot of mods that will net small mileage gains. The problem is cost. How long does it take to recover the cost of a $350 part if you gain 2mpg? For some people it's worth it, and for some it's not.

If you add a $6 bottle of fuel additive and gain 1mpg, did you save any money? That depends on how much you're paying for fuel.

I have yet to see a proven test on aftermarket air cleaners that improves power or mileage on an otherwise stock or mostly stock truck. If I ever see actual proof, I might buy one. Otherwise, that's $300+ wasted.

The best mileage gains are free. Keep the boost low, by being easy on the go pedal. High boost comes with high load, and that burns more fuel.

These trucks (mine, at least) are very sensative to speed. I guess because they're about as aerodynamic as my garage. My truck gets much better mileag (21) at 50-55 than it does at 75-80mph (18).

I never recommend filling the tires to max sidewall pressure. And neither does any tire maker I know of. You will get better mileage. But you sacrifice ride, handeling,transient response, braking, and wear. The goal of better mileage is to reduce cost. But if you wear out the tires 20-30% sooner, it ends up costing you more. Use the proper tire pressure based on use and conditions.

Oh, and don't fall for that Nitrogen scam, either.

 

The best mod for mpg gains is a pyro and boost gauge. Timing and a little rail pressure increase help. Keep the boost less than 6 psi and pyro less than 600. Lower on those numbers the better if you maintain speed. On my rig with 3:73 ratio and keeping speed to 60-65 mph hwy I repeatedly get 21-23 mpg empty, hand calculated filling the tank to the filler neck. Total city driving 16-18, towing 12-14 and driving empty 75 plus 18. I know the 2wd 03-04 are the best of the 3rd gens. Worked with a guy who drove pilot for big loads that got 25-27, he did remove the rear spring spacers

 

The 3.42 gears is what has helped the most with everything he has done. Curious as to where he got his gears from. A freind of mine installed some 3.53 gears for his 05, but would have liked to of gotten something higher.

 

That is why I was wondering about the stainless exhaust manifold,,,and the banks intercooler to go with the stuff ive already bought and put on....

will it help lower egt's enough ???? and to keep the boost @ 6 or less,,,55-60 mph???? It seems what the talk is the SST Exh. Manifold lets the turbo spool easier but lowers EGT's be cause its less of a heat sink,,, so wont that run the boost up higher?????? my truck is basically a stocker with a few bolt on parts,, and they are getting more expensive as I go LOLOL!!!

And I think Bob's assesment of sacrificing early wear out of your tires and ride by making bricks out of your tires for a couple of MPG is a good one!!!!! I inflate the rears to the rated Max when I pull the Race car hauler,,,, but about 5 below for running empty or pulling the boat,,, and the ride is good,,,

 

I think I'm following your logic, but want to point out a very important fact. Our electronically controlled 3rd gen cummins, fuel by the boost number, the ecm receives from the map sensor. So in your case. with stock fueling a banks intercooler and/or sst exhaust manifold will not improve your mileage. Lower the boost number the less fuel is injected and the lower the egt numbers. However, the higher you go in fueling the mods , a intercooler will lower your egt's if you are running a chip or programmer with a aftermarket turbo, but since your increasing the boost the motor injects more fuel..........make sense?
The 6 boost and 600 egt are proven over the years from the OTR big rigs for mileage. Speed kills fuel consumption.

 

My ARE bed cover made a decent gain. Smarty beta 4.4 on setting 3 gets my 50/50 city hwy from 17-17.5 to 19-19.5 and if I stay under 65 I have pulled down 21-22.5 no wind no a/c. I have the AFE, but I am going back to stock box with 4" tubing out the bottom. Hot air does not make MPG. I also have the locking hubs in the back of my truck and will be interested in the results. I bought them as an upgrade to the unit bearings and I need u-joints also. Dynatrac had a deal where the hd units were on sale for the same price as the std ones and when I paid freight they threw in new U-Joints. With 35" Fun Country II's on I feel I am doing pretty well. I am adding a ATS manifold and an he 351 turbo in the very near future also. The bed cover made a huge gain at 75+ "went from 14-15 at 75-85 to 17-17.5" but not as much driving to work. I think the key is the beta 4.4 with extra timing and a little rail psi. Remember we have a 7800 pound truck with the aerodynamics of a brick.

 

LOL!!! good for you cause I'm cornfuzed!!!!!!

I am running a chip but the turbo is stock,,, considering sending mine off to a turbo Wizard and getting it upgraded and adding the upgraded intercooler @ the same time,,, The High Ram Intake and Ram Air Cold Air Intake combo did wake up the throttle Response nicely So,,, the more Mods,,, performance goes up however,,,,, mileage is out the window Ehhh????

been toying with the Idea of a Smarty Jr.

 

Yup you got it.......what chip are you running? Still, if you get some gauges the boost number directly relates to mpg...simple Why don't you tell us more about your rig. filling in your sig? Guys with more knowledge than me will probably chime in.

 

Thanks,, the truck is described in post # 10,, sans silencer ring delete,,, Ive tried to load my sig on this antique computer and it is stuck on preview sig,,,???????? or is the protocall such that a moderator have to review it before it can be posted????

LOLOL!!!!

 

Ohhhh Tay Buttwheat,,,, It's there now!!!!!! LOLOL!!!!!!

 

So far nobody has really mentioned the benifit of having a programmer to gain MPG. Would a Smarty (or similar programmer) really net me 2 MPG on a stock truck? Is it really worth the $500-600 or would I only see the fuel gains if I had other mods done? Also I have heard that running a programmer on a higher setting with a light foot would help. Is this true or just a bunch of bs?

 

I Put my MP8 on before the bolt on mods,,, I realized a gain in MPG,,, read post 10,,, but as you questioned,,, yes that was with a lite foot and the chip turned up,,, the problem being is keeping a light foot!!!!!

BTW I pulled the silencer ring when I added the Banks Ram Air

My truck is still basically stock,,, turbo, stock injectors, stock fuel system,
as previously stated by others a boost guage/driving habits (slow down) will help you gain MPG by keeping Boost > 7lb.

 

That's one of the few mods that can actually gain some MPG, depending on how you drive. If you drive in town a lot, you can decrease the fueling and decrease power. You'll notice a differance in throttle response and available power. But the 5.9 makes so much torque that it won't really matter.

Driving on the highway takes X amount of power, and will burn Y amount of fuel. De-fueling won't change that.

The big advantage to a good tuner is that you can adjust certain parameters for your particular driving style. Towing a 10K# trailer through the rockies is a lot differant than crusing empty in FL.

 

Quote:

Originally Posted by N.Johnson

The best mod for mpg gains is a pyro and boost gauge. Timing and a little rail pressure increase help. Keep the boost less than 6 psi and pyro less than 600. Lower on those numbers the better if you maintain speed. On my rig with 3:73 ratio and keeping speed to 60-65 mph hwy I repeatedly get 21-23 mpg empty, hand calculated filling the tank to the filler neck. Total city driving 16-18, towing 12-14 and driving empty 75 plus 18. I know the 2wd 03-04 are the best of the 3rd gens.

These are consistent with my numbers. I drive ALL miles at 1700-1900 rpm, ZERO exceptions; solo or towing. Town is 19 mpg the last two years. Fuel mileage was paramount to making a heavy pickup work for me, so I purposely sought an '03-'04 2WD (also wanted the IFS and variable-ratio rack & pinion steering) with an NV-5600. I know the 555 motor is the best of all the CTD versions.

I am using OEM fluids, etc, so there is no "magic" involved. Pay attention to rpm rise with successive shifts (progressive) and only use the throttle as a way to move between gears. It is a different approach (the one used by big truck drivers) but it pays dividends.

I also coast quite a ways towards any stops; drop speed and/or gear on exit ramps/flyovers (never more than 10 mph above "suggested" speed) as one wants no surprises . . . . knowing how to use the brakes is the second half of the equation. I've never had to stand on them, or even brake 3/4 hard more than once (with heavy trailer).

Let the gears control the momentum, NEVER the throttle. You work for the engine, the engine does not work for you, it works for the load. Your job is to make the engines life as easy as possible.

Some folks may think that an annual average difference between my truck at 19 mpg and another at 16 mpg is minor (all solo miles to make comparison quick). At $2.50/gl diesel, at 25,000-miles annually, my truck has covered the same distance for a savings in fuel alone of

$3,700

the past six years or 150,000-miles. If fuel had been $3/gl, that would be a fuel cost of $23,685. For a truck averaging 16 mpg annually, the cost would have been $28,125; or,

$4,450.

You work for the truck, the truck doesn't work for you. With that attitude, mileage increases and expenses decrease (all expenses, current and future). When the hypothetical other man and I sell our identical trucks for identical sales prices I have made an additional four thousand dollars +/- over him if we sell today.

Think on that.

 

Hmmmmmmm???? You Go Boy!!!!!!!