Another Truck....

[DeckSetter]

Long time lurker, new poster......

I'm a carpenter, and I use my truck for work. For 3 years I've been driving a '97 Dakota 5.2l 4x4 5spd with a 3" body lift and 33x12.5's...... HORRIBLE on fuel (usually 13-14mpg, never over 15.5 since the lift and tires) and it was time for a change.

A month or so ago I bought a 2000 GMC Sierra 4x4 4.8l auto. I've been getting around 16mpg with it so far, which is a definite improvement over the Dakota, but I'm looking for more (of course!). One tank I had a lot of longer trips at 55-60mph and squeaked out 18.4mpg! With that one tank (29.5 gallon fill ups from the low fuel light) I figured I saved around $35 over driving the Dakota.

Where should I start? Chin spoiler? Lower it? Take off mud flaps?

[DeckSetter]

[Ed-in-Maine]

Hi Decksetter, if you don't already have a ScanGuage II real time data from the ODBII port, get one! The constant feedback is great at changing driving habits. On my last refill I managed 17mpg doing cold start short drives 75% of the time. I don't have good ABA but I'm sure that before I would have gotten 15.
Ed

[slowmover]

Originally Posted by Ed-in-Maine

Hi Decksetter, if you don't already have a ScanGuage II real time data from the ODBII port, get one! The constant feedback is great at changing driving habits. On my last refill I managed 17mpg doing cold start short drives 75% of the time. I don't have good ABA but I'm sure that before I would have gotten 15.
Ed

Along with this: careful records of all gallons and all miles (which you may already be doing). An understanding of CPM calculations (AAA and OOIDA downloads) for business purposes. As the truck is a business tool so knowing it's exact relation to income is crucial. Project future fuel costs at $6/gl for some margin (calendar year 2013, for instance; to adjust other expenses in relation). Fuel may not go that high, but I'd rather have a handle on the way it affects my income to make plans now.

I also like to know average mph as a way of keeping any idle time as low as possible. Higher average = better FE. Using MAPQUEST "best routing" is beneficial (similar to how FEDEX and UPS dispatch their trucks).

Fuel economy is seen, IMO, in relation to annual average mpg. Any increases are simply as a percentage increase of that number. 16-cpm fuel cost to 14-cpm doesn't seem impressive until we see it as a 23% improvement (or however the numbers may work).

And it's not enough to know the fuel cost, per mile, but the true cost per mile as well (depreciation, taxes, maintenance, repairs, etc). The adjusted IRS deduction goes to a savings account for truck expenditures. (Every job pays both the truck and the owner . . separately). I pay the truck before I pay myself, IOW. (A good incentive as it makes the truck my expensive helper and not "my slave").

Further, an analysis via records of distances the truck travels per job. Mostly town miles argues against aero (unless really cheap), but extended highway is the reverse. But, in both cases best LRR tires are beneficial (especially if the tire brand/model is known for very long life) such as LT-rated MICHELIN (see their site).

On the truck I'd start with issues of rolling efficiency. Do all book maintenance and a bit more, then:

- perfect (not just good) wheel alignment
- zero brake drag
- zero steering wander

Tires and brakes should be lasting above 70k. If not, then some driver-adjustments may be needed.

Little things, IMO, like polyurethane anti-roll bar bushings (and adding a rear bar if not so equipped; HELWIG or ADDCO) are good for straight-ahead stability. Best shock absorbers (such as BILSTEIN). Wind and bed loads work against that stability and increase steering corrections per mile (which is bad for FE). The side loads imposed by winds on a truck with bed topper are noticeable, especially when loaded up.

When I buy a vehicle my first step is to get a certified scale reading (CAT Scale) with driver, full fuel and permanent load additions. Good to check against in future as gas engined vehicles tend to be weight sensitive and "trunk junk" tends to accummulate over time.

I've seen the argument that a work trailer (carrying the JOBOX and other tools) that can be left at the site (or disconnected on non-work days) is a good way to keep solo vehicle mpg higher.

And little things like LED exterior lamps, etc, may also add to long-term efficiency. A little more up front $, but less electrical drain and they live longer plus provide better performance. A search around this site may reveal more of this kind of thing.

.

[Ed-in-Maine]

The one really easy habit mod has been to shift in to neutral at lights and for coast down hills. This habit came directly from observing the scanguage i.e. GPH higher in gear. I can't see any negative to doing this and it's just a habit. At first my wife gave me a look but now she doesn't even notice
Ed

[slowmover]

Originally Posted by Ed-in-Maine

The one really easy habit mod has been to shift in to neutral at lights and for coast down hills. This habit came directly from observing the scanguage i.e. GPH higher in gear. I can't see any negative to doing this and it's just a habit. At first my wife gave me a look but now she doesn't even notice
Ed

So long as one is aware that to be out of gear while operating on the roadway is illegal. Keep that awareness is all I'm saying.

[Ed-in-Maine]

Originally Posted by slowmover

So long as one is aware that to be out of gear while operating on the roadway is illegal. Keep that awareness is all I'm saying.

OMG Then I've broken the law every time I've driven a stick Oh well I've heard a prominent law professors say the average person breaks the law every day, there are just too many stupid laws on the books for even the average police officer to know them all
Instance- I used to teach Motorcycle Safety classes in Maryland, part of MSF, and we all knew it was illegal to ride a MC over 50cc without a drivers license and registration had the code in front of us. And if under it had to have aux pedals i.e. a moped. Well then these kids start blasting around on 250cc scooters sans tags on the streets right past the police I asked 4 different police officers(we lived near a substation and I'd catch them on the way out) and not one could tell me if these 250cc's were breaking the law. Since I don't ride that small anymore I quit trying to figure it out.
Ed

[slowmover]

OMG Then I've broken the law every time I've driven a stick

Call it philosophical, E-I-Maine.

It's not a question of virility. I have over time come to be amused by driving skill = intelligence as it is un-intelligent to assume that I will always be healthy, alert, rested and not distracted when behind the wheel. Therefore, habits should assume a lower order of operational skill.

The OP has an automatic. Habits formed around that transmission type made my addendum to your advice worthwhile, I thought, as few ever drive them that way (beyond helping cool an AT at stoplights in N) and it can take awhile to make the change (if warranted). Stick it in gear, stab & steer is different than the foot work and awareness of driving a standard. Agreed?

There may be instances, therefore (a loaded work truck after all, not a commuter) where mass-in-motion makes being in N a bit uneasy with an automatic. Knowing the rpm to bring it back into gear to maintain road speed also has to take into account torque converter slop. That's actually more difficult than with a standard.

The only time I take my truck out of gear while rolling is the last bit to a full stop. Or, if no one is overtaking me on a long downslope. Not otherwise. IOW, not a "habit" I wish to make, but a clear choice every time. The benefit isn't large after all . . but the downside is.

Only a few times of having to get an unwieldy, unbalanced 40k load on a flatbed to it's destination while tired, injured and confounded by traffic and weather made me a believer in at what assumed level to establish driving habits. (And if that wasn't enough, it was the story of my late father who -- with senile dementia -- had such good habits behind the wheel that the DPS and even one of their supervisors in several tries found it impossible to technically fail him. Conversation, etc, made no difference. HA!!).

.

[Ed-in-Maine]

slowmover - thoughtful... thanks. I only meant "Habit" in the framework of any driving tasks be it back when I drove a 3 on the tree or the current 4,5,6 on the floor, i.e. once it's a habit it takes much less cpu cycles to do it correctly in any given situation. SO we have a slightly differing view of the word "habit" that's all. Because with practice one can easily double clutch down shift while heal to toe braking and entering a hard corner and after enough times it's a "habit"(to me) and the leftover cycles are for watching everything else. (philosophy off)
Ed

[4ringcircus]

Hi DeckSetter. First and foremost: Drive slow. Trucks have poor aerodynamic shapes, and wind resistance increases exponentially with speed. Keep at or below 55 and you'll see huge improvements.
A few easy mods:
1. yes, remove the mudflaps. Fast, easy and free.
2. Reduce weight: That fiberglass topper probably weighs over 200lbs; remove it when you don't absolutely need it. That said, the topper improves aerodynamics compared to an open bed. If you driving mostly fast highway speeds, you might not experience mileage gains after removal. Best of both worlds: lose the topper and maintain good aerodynamics with a light weight (vinyl instead of fiberglass) tonneau cover.
3. Redirect air so it does not go under your truck. The hard way is to lower it, the easy way is to take some black plastic garden edging and screw it on to the lower valance of your front bumper.
4. Heat the engine quicker. I can see by the bare trees you live in a cold climate. Add insulation to the underside of your hood. It will both heat up faster, and keep it warmer longer. Careful to not let the insulation touch anything that could make it start on fire~ I put a simple foam egg crate over the top of the engine bay. The only thing it touches is the air intake.
5. Free up horsepower: Haven't done this myself just yet, but consider an electric fan. Note that if you are idling a lot, e-fans actually use more energy and reduce mpg. But if your moving, they should improve matters.
6. Aerodynamics: Add a grill block. Careful of over heating if you combine 5 & 6. I got an aftermarket temp gauge so I could accurately monitor my engine temp.