farmer13

I went from stock injectors to the rv 275 injectors. before I did this I got around 600K to a tank of fuel now I get a little better than 800K. I also add 2 stroke oil to every tank fill.

TOM R

airdam where?, i won't level or lower the truck cause it sits perfect with the trailer on

Diesel Doc

If you look at my sig you can't get much bigger than 220hp over injectors. I have to say that this is the largest misconception with injectors. Larger injectors CAN flow more fuel. They don't flow more fuel all of the time just when needed. When you upgrade a Cat 3406E from 435hp to 500+ you put larger injectors in and a larger turbo. In nearly every circumstance they still get the same or better mileage. On a 12 or 24vlv engine the injector doesn't meter the amount of fuel entering the engine the ip does so I still see no way that injectors alone can hurt mileage if you are not jamming on it all of the time.

wjbell

I've recently found out that the silencer ring robs a little bit of mileage. I had it on for the last few tanks and consistently got 15.5-16.5 mpg in town. As soon as I took it off it went to 17.5.

My truck gets an average of 17.5 city and I think I can get about 23 hwy. (still need to do a 100% hwy run)

I have a 01 2wd and took the stock 1" lift blocks out of the back end, put in 4" exhaust, edge ez on level 1, made an extended air dam for the front and made block off covers for the two top grill openings and the two bottom openings on the bumper. I think the aerodynamic mods really make a difference, only for speeds over 50 mph of course.

bentwings

WJbell, I did almost the same thing. I made smoked Lexan block off for all 4 upper openings for winter fronts. They definitely help mileage. I can't put a number on but fall driving before winter fuel tipped me off. I'd guess 1 mpg anyway.

This year I experimented and left them on for the summer. Even in 90+ temps I only get to 190 maybe 200 going up hill so I've left them on for good.

I don't think these are especially good winter fronts as too much air still gets in when it is below 0. I'll probably add the cardboard with a fan hole for the really cold days this year to try this out.

I like the air dam idea too. I've contemplated this for a while as I drive 90 % highway now. 21-22 mpg 55 mph in the right lane. I think a more front mounted one and wider and lower would be very effective. It needs to have a road kill flexible center section too. haha I sure would hate to hit a skunk with it.

wjbell

I live in Sacramento, Ca and summers get pretty hot so I didn't want to block off all 4. But the way it is now in 100 degree heat the temp stays normal.

I was thinking of a bigger air dam but didn't want something that looked out of place or too noticeable. If you look straight on from the front it totally blocks the air from all the front suspension.

tbrunson

Been talking to a local diesel performance shop and they said for the 2nd gens the quad or edge ez is the way to go for mileage on the boxes. Generally speaking, "stage 2" injectors and going light on the pedal will help mileage from what they've seen. Think I've read that switching out our stock engine fan for the flex-a-lite dual electric system will give 1-2mpgs extra, check for yourself and they run around $550.00 if memory serves.

Way back when, a few of us (friends acquaintances) had sports cars with turbos, tweaking down the boost just a bit on a 9:1 compression engine helped mileage unless we were romping on the pedal. Don't know if this will work on these diesels though. Just an idea. There's another thread here I read a few weeks ago about putting in a higher temp thermostat to get mileage up too.

Oh, I don't know if anyone else has been studying this lately, but I've noticed my mileage is significantly better if I keep my tank above 1/2 full. Is this a fluke with gauge or are evap. and easier pick up a possibility here? Thanks.

cody_d

I dont remember what month it was, but i read in Diesel Power Magazine that they had a duely that they had gotten up to 41?? mpg i thing (or there abouts). If i remember right, they had a 2-wheel drive duely, and they had covered all the rims in cardbord, covered all but one front vent (the one uncovered was in the hood, they also had a bed cover on it, and had folded the mirrors in and i think plastic wraped them.

With my truck i get about 17mpg in town, and have gotten as good as 19.89mpg (took mileage off my gps on an all freeway trip which was 50 /50 hills) I averaged about 63mph on that trip as well (gps averaged the speed). I have no idea how i'm getting what i'm getting, having the 4:10 gears and with my truck being taller, having the suplimental suspension package (basicly makes it a 1 ton)

dozer12216

Taller tires will help. I like the higher temp theromstat but have not really found one that changes temp. I don't believe snake oils will add any appreciable milage. You will get better milage in spring and fall. Remove any non essential weight. A good wax job that at least makes it look better. I have gotten 22 MPG on my dually, but was drafting another truck at about 100 feet to achieve. The cooling fan only pulls when temp goes over 210 or so and you need it then. If a chip slightly increases timing it might help. JMHO

hopak

1/2 oz/gal 2 stroke oil made a difference for me.

rfeiller

notice that the pre '03 get considerably better mpg than the newer ones, no matter what we do.
would like to be assured that those mpgs are hand calculated and for at least 500miles and not partial fill-ups or short runs

supr

The best way(hardest for most?) is to just slow down. Driving 50-55 mph will cut wind resistance and improve to close to max mpg. At 45-50 I can get 20 mpg, about as good as it gets with 4.10 gears/dually. at 60+ mph and up, it starts to drop. If you have a temp gauge, you can watch you temp rise from 45 on up. The higer the temp, the more fuel you are burning.
Somtimes we have to run 70 to get some place. But if I have the time, I slow down.

WestTN

I have
:slowed to 55mph on the highway
:loaded the 'Fuel Saver Smarty tune
:set tire pressure to 60psi
:shift at 1500rpms

Several tanks at 24+mpg.

While towing my 29 ft Terry Taurus conventional TT under the above conditions with the exception of higher shift points, I am getting 15+mpg.

SIXSLUG

Electric fans can save 24 hp and smaller side mirrors, if you don't tow. Salt flat racers developed the old school 'moonie' discs to keep drag and turbulence to a minimum during hi speed runs. These could affect your brake cooling though, many stock rims are designed to also pull in air to help cool brakes.
If any of the fuel straighteners worked the auto manufacturers would already include them in the vehicle.
Just slow down and be happy you get what you do out of a 3 1/2 ton truck!

Kurt

nitrousn

That would be the fastest loss of 550 bucks you have ever seen. The cummins make so much torque and power at low rpms that is does not even know the fan is there. Save your weasel skins on that one.