My Honest MPG. Desperate to increase it.
 

Hey guys. I purchased my truck NEW in 06. It is a auto with 4.10 rear end, and narrow 34 inch Hankook Dynapros with 70lbs pressure in front, and 60lbs in rear when empty. Qaud Cab short box. From new to about 15k, it averaged about 10mpg in town, and 13mpg highway at about 75mph. That was to be expected. Truck now has 70k miles on it. Have towed hard about 5 times a year, each year...so not really a lot of towing, but enough (I think) to break her in a little. The weight has always been the same. A dump trailer with 18k pounds of gravel in it for 280 miles. I help a guy out each year who needs some gravel brought to him. Truck very rarely is driven around town, almost all highway. Truck has NEVER smoked at start up, even in -30 below weather unplugged....just never a puff. All oil samples come back perfect. Truck runs great! Never a hiccup. (spelling) Have had temps up to 1400 degrees a few times, and ran it at 1250 - 1300 degrees hard and long so tips are not fouled up. Fuel tank has NEVER been filled up with out an over kill amount of Stanadyne or Power Service in it. Truck got up to about 16mpg at one time, then I put a leveling kit on it and a TDK bumper and lost 1mpg. Now truck averages 15mpg highway, and 12 in town. When I tow my 2k pound boat at 70mph, I get 11mpg. If I keep her at 60mph, I can get 18mpg. 16mpg at 70mph. I'm not going to drive 60mph. I have every air mod one could through at the truck. Exhaust, intake, CFM, exhaust manifold, and more. This poor mileage has been really bothering me lately. I run the Smarty SR on level 1 and everything default. Why am I getting such poor mileage compared to others? Is it the simple fact that I have a 4.10 rear end? That its an auto, which by the way, I thought it had taller gears than the 6spd manual? Any help would be much appreciated. I need to do something here. Thanks guys!


Jason

I see your running bigger tires also. Heavier front bumper to. 4.10 aren't helping much either.

If you don't slow down, you're not going to get better mileage. It's a very simple aerodynamic equation, and you're essentially displacing the airmass of your truck as you drive. The faster you drive, the greater the resistance, hence the higher rate of fuel burn. You could lower the truck, change the gears, run an overdrive unit, skirt out the airdam and chassis, and you still wouldn't pick up as much mileage as you would by slowing down to 60mph. Every little bit helps, but it all stems from speed...

See ol Zach n Tim about some injector cleaner. See if they got some BG. It's about $60 for a quart though. May also want to think about getting taller gears. 3.73's or 3.54's?

How are so many others with pretty much the same setup or close too, getting this "18 and 19" mpg under normal driving conditions....normal highway speeds, etc...either most aren't being truthful, or my pickup just doesn't get decent mileage. Is there a paticular Smarty setting that seems to do a little better for mileage? Also, I chose a taller skinnier tire to turn a little lower RPM's. I actually think that helped.

My 05 with 62k gets a constant 20 mpg in the summer (rural and hwy). But I have 3:73 gears with 265/70/17 tires.
I also have a quad box (run on PL2) and a bed cover.
Winter fuel brings me down to 17 mpg (all hand figured.)

It's not just top speed. How fast of a stop and takeoff is another big factor. My FIL drives with either the brake or the gas to the floor. Nothing in between, yet he always gripes about how crappy his mileage is.

Look into hypermileing (sp??)

your 06 has 3.73's not 4.10. you will have to get rid of the in-cylinder egr to get it up i am confused about exhaust it shows a 5" tip but that is worthless you need a 5" turbo back. you have the smarty just change the cam to a pdr or colt and get some ddp hp nozzles. this will get you into the twenties. that junk auto will always cost you 1 mpg plus a big fat maintenance bill the rest of the trucks life. ( some say i may be slightly predigest against the auto )

My truck has averaged 18.69 mpg over the last 30,105 miles, using 1617.91 gallons of fuel. In the winter I get an average of 17.34 and in the summer I average 20.21. My best mileage ever was 21.34 and that was at low speed on a round trip up and down a mountain pass. When I drive over 1900rpm (about 64mph) my mileage drops to 18.3, or about 10%. when I drive over 2100rpm (about 70mph) my mileage drops to 16.9, or another 8%. By slowing down 6mph, I improve fuel economy by 18%.
There has been no other change I'm able to make that is even close to the same improvement.

I ran a Quad MMM box and improved less than 5%. The Smarty Jr added 5% until I ran larger tires, then I got 8%. By keeping boost below 10psi and shifting at 1600-1800rpm, I gained another 5%. It's hard to do, especially when the Smarty almost dares me to smash the pedal, but in the end it ends up saving me about $18/wk, or almost $1K a year. For an extra grand, I'll drive in the right lane and let people go by all day long. Most of the time I meet them at the first stoplight anyway, and the only thing they've done is burn more fuel and sit at the light idling longer than I did.

Turn the Smarty up to level 5 or 7. Since you don't have the auto upgrades, be easy on the pedal. It will help some. Back your speed down to 68-69 mph. You can change gears but you won't gain much in my opinion for what your going to pay for the sway. It will buy alot of diesel.

All of what they said +1

You're pushing a lot of air, already have screwed up the gear ration by using tall tires so changing the ration to 3.somethings isn't going to help. You're already there.
Your speed is killing you.
I just got back from hauling 3000# of household crap on my 26' flatbed tandem axle trailer from Chico to Sanata Barbara, about 850 miles round trip... I was averaging 17 mpg down (running 58-60 loaded) and 19 coming back that night (running 60-65 empty). My 1-ton has 4.10's in it and I've got ever kind of mileage enhancer in this truck I could do short of a complete change to the engine like suggested above. Taking off quik kills you're mileage as does sitting at the stop lights.
I think a change in driving habits will help a little but your rig is just not built up to be fuel effieicent. 4WD's just aren't. Aerodynamically and mechanically.

Ditto what Adaminak says. RPMs/MPH is the biggest factor(s).

Cut weight, drive slower.

That is the only way my '06 sees 20+MPG. Anything over 2,000 RPMs with stock everything and 2wd still rapidly drops to the 16-18MPG area and lower. I make the movie "Driving Miss Daisy" look like "Days of Thunder".[laugh]

Not sure if you were replying to my pickup, but it does have 4.10 gears in it. As far as exhaust, it is 4 inch turbo back duals with not cat and free flow muffler. As far as driving habits, I generally only cruise 70mph.....almost always. On the 75mph interstates, 70mph, on the 70 mph highways, 65. I just can't do 60mph. I live in Montana. Everywhere is far, and takes what seems like forever to get too. 150 miles in any directios to get to anything. As far as driving habits, my wife hates it when I drive, and so do most behind me. It takes me a good 2 seconds to even get the pickup moving from a stop light, and another 10 sec to get her to 20mph. [laugh] ....really. Drive like there truley is an egg under my right foot. I have seen 20mpg, but that was with a decent 15mph tail wind, and going from a 6k ft elevevation to 2400 ft elevation, at a little under 70mph. I just don't think all trucks get this 19-20mpg average. I see very few people actually driving like me....slow. Sure I could probably accomplish 20mpg consistantly if I drove 50mph, but apples to apples, I'm hearing so many saying there achieving 19mpg at 75mph emtpy. I'm just not seeing it. Tranny is in the works, well, the saving money part for it is. Maybe I'll pickup a little there. I guess I'll try smarty on 5 or 7....not worried about the trans holding up cause right pedal vary rarely has ever seen the floor, and will probably remain that way. Would just love to get 2mpg more like everyone else is getting.

People driving 75mph and getting 19mpg or more are most likely full of it.

Unless...they have changed gears in the tranny or installed some overdrive unit OR they are hypermiling their butts off with a manual transmission in a dropped 2wd with reduced wind resistance.

Also, if they are hypermiling and driving like I do...there is a point where they must load the engine and put the tach near redline just to blow the soot build up out of the tail-pipe.

The math just doesn't work out gear wise. There is a point of diminishing returns with mileage modifications when people start modifying hp/tq and gears and that point is not too far out there. If someone can get to 75mph under 2,000 rpms then it is a reality...but how much does it cost in modifications to make that happen? Maybe some oilfield part runner that puts 500,000 miles plus on a rig can justify the financial costs of creating those kind of rpms to achieve 75mph and 19mph+...most can't.

You can add up to 10% to your economy right off the bat if you upgraded from 30-31inch tires to 34's. The odometer is counting off miles based on the stock tire diameter. That puts you at 17.5 or so at 70 mph and near 20 at 70 mph.