What can be done to improve fuel economy?

[jdmetcalf57]

My truck is a '99 K3500 4wd at drw crew cab. Many people may not be satisfied with the stock power but I am. I don't need to burn my tires off.

However I am tired of sending $3000 a year to the Middle East from the need for fuel just in this truck. According to my calculations I can spend about $1000 to gain 1mpg to pay back in 100k miles There is also much satisfaction in not supporting the crazys over there as much. It's also more fun to tinker with these trucks than to pay the fuel man.

The following is a list of things that will help our trucks and engines improve fuel economy:

1. drive slower
2. change gearing or add overdrive transmision.
3. use fuel conditioner.
4. use a larger exhaust (reduce restrictions)
5. eliminate turbulence causing protrusions like bug sheilds
6. insulate the crossover pipe.
7. Increase the TDC learn setting. (mine now -1.8)

These things I have done and have probably gained 1.5-2mpg towing mileage.

Other things I am considering is:
8. change to manual transmision.
9. Change to SRW.
10. Increase turbo boost.
11. Add intercooler.

I am not sure how much 8-11 will help. I would like to know what other people think, their experience with these and what fuel economy they think might be gained by these. Is there anything else that we can do?

[Dvldog 8793]

Howdy
AMEN to the "Crazies over there"!!!!
If you already have changed your gears, maybe switch to a smaller tire for less rolling resistance. Also maybe try lowering the whole truck. Make sure your truck has the lower plastic air dam in the front, mine did not. I would think changing to SRWs would make a large difference. I would think an IC would be benificial as long as you don't crank up the fuel level also. Synthetic fluids in the diffs/trany makes some difference. Switch to a turbo-master control and eliminate the vac-pump, it has to rob something to run it.
All it takes is MONEY! :D
L8r
Conley Janssen
USMC 87-93

[sk8rdi16]

Run Biodiesel or better yet Waste Vegetable Oil!!! Check it out. I am about to convert my 95 suburban once I get it properly running (FSD, not enough boost, etc). Check out www.greasecar.com, (http://www.greasecar.com) www.greasel.com, (http://www.greasel.com) etc.

Pat

[ 09-14-2004, 09:33 AM: Message edited by: JohnC ]

[DA BIG ONE]

Originally posted by sk8rdi16:
Run Biodiesel or better yet Waste Vegetable Oil!!! Check it out. I am about to convert my 95 suburban once I get it properly running (FSD, not enough boost, etc). Check out www.greasecar.com, (http://www.greasecar.com,) www.greasel.com, (http://www.greasel.com,) etc.

Pat With 1 bio-diesel distributor here in Florida its cost is $3.00 gal. so not an option here yet1

I had changed to 3.42:1 from 4.10:1. However, the fuel milage sucked after the gear change until I hacked the VSSB, then fuel milage increased big time!

Forget the airdam if you run an IC.

[Hye]

Greasel.com and greasecar.com I think the commas will keep the links from working in the previous post.

Pat, let us know how it goes. This could give a new meaning to the term V-8 diesel.

[jdmetcalf57]

Unfortunately alternate fuels don't seem to be an option. Most of my fuel is purchased far away from home, much of it on the way out west or to Florida.

Of course I could stay home but what fun would that be? This is the corn belt.

[Dvldog 8793]

Howdy
In the north it is difficult to get the grease up to flow temp when it is -40*F. I have a freaind that uses it in a VW, he gets about 60MPG! :eek:
So it really pays off, but he does have some problems in the winter.
L8r
Conley Janssen

[sturgeon-phish]

I've done a few things to improve the fuel economy and they have helped and all with minimum investment.
Cleaned up & enlarged the openings in the airbox to lessen airflow restriction. Installed amsoil air filter, oil and trans fluid. Gutted the cat converter. Run tire pressure to max on sidewall. Take unneeded stuff out of the bed and behind the seat.
Something I'm working on now is replacing the stock front running light/turn signals with a smaller unit, and opening the air flow to the airbox intake behind the passenger's side light. I'll post the outcome of the results.
Yet to come, better exhaust/downpipe. $$$. I can easily get an honest 20 mpg now.
Hope this helps.
Jim

[sk8rdi16]

Everyone sounds real handy with their trucks, bring that down to the biodiesel! Make your own!! very easy directions can be found. try www.journeytoforever.org (http://www.journeytoforever.org)
I will let everyone know how it goes. Down here in South MS, I don't think I will have flow problems even in the winter!!

Pat

[jdmetcalf57]

Does anyone have experience with how much fuel economy gains, if any will be seen with an intercooler.

Any ideas on how much a manual helps over an automatic. I'm thinking a manual helps more towing than unloaded because the torque converter slips (with out the TCC engaged) a lot more coming up to speed.

[catmandoo]

one thing i haven't seen mentioned is a topper,when i put one on mine i picked up an instant 2 mpg

[Marty Lau]

Originally posted by catmandoo:
one thing i haven't seen mentioned is a topper,when i put one on mine i picked up an instant 2 mpg Hmm, I lost 1/2 MPG but mine doesn't follow the roof line very well infact it stick up about 2 inches above the roof line. I'm sure a "custom" topper that flows with the roof would do better.

[jdmetcalf57]

I too loose mileage adding a topper. One thing most people don't realize is as far a aerodynamics the shape of the tail probably has 5 times the effect of the front. A long gentle sloping tail is best. Just look at a jet liner or a porpoise. A square cut off like most toppers is the worst. However aerodynamics is fickle and affected a lot by surrounding shapes or protusions.

[catmandoo]

mine is cab height and rounded in the back not like those aluminum ones that are square.

[tom.mcinerney]

Several members have reported that installation of a reworked PCM 'chip' not only increased power on demand, but also improved mileage when not at max power. I believe a few commercial chips were said to help.