Just lurking...

[Randy_the_Hack]

Hi all,

I'm driving a 2004.5 Chevy Silverado 2500 HD w/6.6l Duramax diesel. With a number of mods, I'm currently making between 21.7 to 22.5 mpg on summer fuel, running around 67 mph. I decided to join this group so I could further explore ideas about mods I could make to get my mpg's on my 7k lb truck up closer to 25 or more mpg's. I'll post some pics and details in the next few days as time permits.

Randy

[RH77]

Hi, and Welcome to EM...

You're at an advantage having the Diesel for efficiency, but with prices the way they are per gallon, the savings seems to deminish, I suppose.

Wow, the LB7 series kicks out 520 lb-ft of torque (and 300 hp)

Do you tow or haul with your rig? That's some serious power, and some respectable economy numbers.

Are you looking for Aero, other mods, or driving style as your means to 25 MPG?

Enjoy the site, and Best FE to Ya

RH77

[Red]

Beautiful torque.......

Welcome to EM Randy

[Randy_the_Hack]

Originally Posted by RH77

Hi, and Welcome to EM...

You're at an advantage having the Diesel for efficiency, but with prices the way they are per gallon, the savings seems to deminish, I suppose.

Wow, the LB7 series kicks out 520 lb-ft of torque (and 300 hp)

Do you tow or haul with your rig? That's some serious power, and some respectable economy numbers.

Are you looking for Aero, other mods, or driving style as your means to 25 MPG?

Enjoy the site, and Best FE to Ya

RH77

Actually, my truck is an LLY, and the mods I've made to it bring it up to somewhere around 430 RWHP and something near 700 ft-lbs of torque. I haven't made it to a dyno yet, but others with similar mods are in this range.

We have a 24' travel trailer that we tow with the truck, and we have a 15' flatbed trailer we use to haul some other things around from time to time.

I'm looking for both - driving habits and aerodynamics. Still looking at other truck mods to improve efficiency too, but I'm thinking I'm getting pretty close to the limits there. Probably looking more for aero changes than anything at this time.

The reason being is that I just returned from a trip to Florida. Going down running the speed limit I had 2 tanks at 19.7 mpg. Dropping to 2k rpm (which makes 65-66 mph), I made 21.7 mpg. Returned running 67 mph and repeated the mileage right at 21.7 mpg... and I was very careful to watch the driving habits. So... I am convinced at this point that something has to change with the truck to improve the mileage, since my driving habits were well in check, IMHO.

Thanks!

Randy

[RH77]

Originally Posted by Randy_the_Hack

The reason being is that I just returned from a trip to Florida. Going down running the speed limit I had 2 tanks at 19.7 mpg. Dropping to 2k rpm (which makes 65-66 mph), I made 21.7 mpg. Returned running 67 mph and repeated the mileage right at 21.7 mpg... and I was very careful to watch the driving habits.

My mistake on the engine model. Still, that's a mound of torque!

I've learned lately (from a Dodge Avenger rental) that despite speed or RPM drop, wind speed has a huge impact on the final MPG tally (especially on highway trips).

It helps to slow down too

By the way, do you have a ScanGauge or similar feedback device? If not, it's highly recommended so you can get a real-time look at a variety of factors.

Enjoy your journey to 25...

RH77

[Randy_the_Hack]

Originally Posted by RH77

My mistake on the engine model. Still, that's a mound of torque!

I've learned lately (from a Dodge Avenger rental) that despite speed or RPM drop, wind speed has a huge impact on the final MPG tally (especially on highway trips).

It helps to slow down too

By the way, do you have a ScanGauge or similar feedback device? If not, it's highly recommended so you can get a real-time look at a variety of factors.

Enjoy your journey to 25...

RH77

Yep - I use a DiabloSport Predator to get where I am today. They offer a +65 hp economy tune, which improved my mileage from 18+/- to where I am today... plus it'll put a big stupid smile on your face when you mash the "go" pedal. Predator will tell me just about anything I want to know except boost pressure and exhaust gas temperature - gotta add some gauges to get that info.

Randy

[SVOboy]

How interested are you in something like an aero cap, ?

Welcome to ecomodder!

[Randy_the_Hack]

Originally Posted by SVOboy

How interested are you in something like an aero cap, ?

Welcome to ecomodder!

Possibly. I've already asked a question about it to Bondo. I'm also asking in the Diesel Place (www.dieselplace.com) about lowering my truck, to hopefully get the thing out of the wind and hopefully improve the overall aerodynamics. Not sure that belly pans are gonna work - this 3/4 ton truck of mine has lots of big stuff hanging down (exhaust, driveshaft, suspension), and these babies are well known for generating a lot of heat... so an aero cap, rear wheel skirts, aero wheel covers, etc. are probably my first options.

Randy

[RH77]

Originally Posted by Randy_the_Hack

Yep - I use a DiabloSport Predator to get where I am today. They offer a +65 hp economy tune, which improved my mileage from 18+/- to where I am today... plus it'll put a big stupid smile on your face when you mash the "go" pedal. Predator will tell me just about anything I want to know except boost pressure and exhaust gas temperature - gotta add some gauges to get that info.

Randy

Economy tune -- cool stuff. It's seems like theres a pretty big aftermarket for Diesel tech -- is this the case?

There's just something about a finely tuned turbo-D (and the sound)
I saw on a Dodge yesterday "Smoke Doesn't mean it's Broke"

Not sure if you had a chance to see the PINKS episode with the 10-second Ram 4x4. What a machine.

RH77

[igo]

22mpg! I assume you are crushing the epa. Good job!