Tips needed for eco-driving my diesel truck!

[Ryland]

What do you use this truck for? no point is us suggesting mods that are going to make the vehicle less useful to you as a work vehicle.
You might look in to a belly pan for it as the two highest drag parts of a vehicle are the underside and the rear of it and on a truck it seems like the worst part of it is the underside, next up is the drive train with all of the gear boxes, synthetic gear oil should help here, you might also check on higher pressure heavy truck tires, they carry more weight, last longer and have lower rolling resistance but they don't fit on standard rims, however there are a few companies out there who make after market rims that bolt on to your vehicle and take these tires.

[99metro]

Apples to Oranges.

I'm driving my 2003 F250 6.0 diesel/Auto while I fix up my 99 Chevy Metro. You are doing good with your techniques. Make sure you neutral coast down to 25 mph or below approaching stop signs. I found that whether I'm in OD at 52 mph or out of OD at 43 mph, I still get low/mid 20's mpg. Even though you are in NC, you might want to plug it in for a couple hours before heading out for the day. That way you can start it and just drive off. The first few miles is usually your worst mpg due to the cold engine. I had best fuel economy on my "EXTREME" (highest) program on my old F250 and then use light throttle. Do they make a 200+ degree thermostat for the Cummins? That would help keep combustion temps high for better efficiency. If you have a Boost and EGT gauges, try keeping boost to 2 - 3 PSI or less and your EGT as low as possible on acceleration. I was using my steady-state 50 mph EGT temp as my MAX when accelerating. I'm not going to suggest gutting the kitty, because that could be considered violating EPA emission laws and such. Maybe a "high flow" cat converter instead? I wouldn't worry too much about tire pressure but do try to keep them at the factory pressures - these heavy 3/4 tons neutral coast forever it seems. Over-inflating the tires will just wear them down faster and I don't think they will pay for themselves in increased fuel economy.

I'm outta breath now and my fingers are hurting!

[Arragonis]

Originally Posted by MetroMPG

Let's please keep this civil.

If my comment comes across as uncivil, and reading it back maybe it does, then I apologise. Never post when you have just cut your finger on your first aero mod.

Originally Posted by MetroMPG

I really don't care what kind of vehicle someone drives - if they genuinely want to talk about ways to improve economy, that's good in my opinion.

Agreed - it is good that the OP wants to maximise his/her FE. But the type of vehicle is crucial here. It is something which was built for pulling and towing stuff and has been modified to enhance this.

However its being used for a daily commute of 140 miles. The OP has made efforts to save fuel and has got the MPG figure to between 18 and 22 which is good given the weight and engine size.

But its still 7 gallons a day to transport the OP to and from work. A basic 4 banger with eco-driving would do 40-50 MPG, possibly more given some of the success stories on here - thats 3 to 3.5 gallons a day. At $3 a gallon (not sure if that is a correct fuel cost in the US) payback is nudging $9-12 a day, or $50-$60 a week. 20 weeks gets $1k savings. I have loads of things I would like to spend that money on instead of Diesel.

Of course non of this counts if the OP is using the towing/pulling stuff as part of their job each day.

[JasonG]

As mine rarely sees dirt/mud, I changed to 85 series tires that were a tad narrower and had a "commercial" tread. They look a lot like trailer tires from an 18 wheeler. Picked up about 1 mpg from them, run at max psi of course. For you Metro drivers that's a lot going from 14 to 15 mpg ~ 5%
Run your diesel in o/d slow as suggested, just make sure you don't let the rpms get to low or the engine will lug and the turbo will spool down. Your AT may shift out to prevent this, I cant say as mines a MT.

[Dave's Civic Duty]

Originally Posted by nubbzcummins

Quick specs: 06 dodge ram 2500 4x4, 5.9l turbo diesel, 2.5" lift in front to level, 4 spd auto with o/d, cruise control, 3.73 gears, 325/55r22 tires, intake, exhaust, programmer. Tranny has 3 modes: Normal, tow/haul, and o/d off. Normal will make shifts at higher rpms and only lock t/c in o/d at lowest speed of 57mph however if cruise control is on you can maintain locked t/c as low as 1000rpm and around 41mph. Tow/haul makes shifts around 100-200rpm sooner than normal, runs higher fluid pressure in tranny, locks t/c when shifting to 3rd at 34mph and o/d at 53mph. Can go as slow as 28mph in 3rd and 49mph in o/d before the t/c will unlock. O/d off operates like normal except no o/d.

Normal driving conditions: Drive approx 140 miles/day mostly highway with some city driving and probly a dozen traffic lights to deal with. Highway has 45-55mph max and city 35mph max. Terrain is mostly slow rolling hills, some flats, and some pretty decent hils.

With a truck with around 38 sq. ft. frontal area, a fairly bad cd, and over 7000lbs driving efficiently gets tough. Best technique so far has been cruise at 50mph and coasting in neutral down hills along with timing lights and keeping speed up as much as possible as well as keeping idle time to a min. Any help will be appreciated.

At least your Driving a Dodge Cummins. Off the bat, the 6 cylinder diesel seems to bring in the best MPG's. Compared to Chevy or Ford. My alternative is to make my own biodiesel. But with a common rail Cummins you can run a two tank system on WVO (waste Veggie Oil) You drive far enough to make the system work for you. After you warm up you switch from the diesel tank to the WVO tank. I'd do that if I were you. check our Greasecar Vegetable Fuel Systems

You can even find kits on Ebay. Just filter out the chunks or make your own BioD like I'm getting about ready to do. I went to a 2 day seminar to learn all the steps & how to collect & build your own processor. Diesel is the way to go!

Dave

[Weather Spotter]

with the savings possible from driving another vehicle, you might want to look into getting a second car. but do not just look at fuel costs, factor in the plates, registration, insurance, etc on the new car to see if it is real a savings.

[Ryland]

Originally Posted by Weather Spotter

with the savings possible from driving another vehicle, you might want to look into getting a second car. but do not just look at fuel costs, factor in the plates, registration, insurance, etc on the new car to see if it is real a savings.

You also have to look at the savings in oil changes (big engines hold more oil) gear oil changes, the cost of tires (I can buy a set of 4 tires for my car, mount and balance them for less then a single 325/55 R22 tire) when you add it all up the cost of fuel, even in a vehicle that uses that much fuel, the fuel is still a fraction of the cost of driving the vehicle.
But I know people who only own one vehicle and it's full of tools or spends 90% of the time hooked to a trailer that is way way to big for my car to tow, trucks don't have to meet alot of safety or mileage requirements because they are work vehicles.

[Dave's Civic Duty]

For money savings on oil changes just get a bypass filtration system, with this unit, while having oil analysis, it is possible to go 80,000 miles until a complete oil change.
Can't help on a cheap way to do tires & replacement parts do cost more, clutches, bearings, tie rods, ball joints, et all, do cost more. Trucks can do a lot of work though. I couldn't pull my horse trailer w/ my Civic or bring home 125 bales of hay & my dual axle trailer. Pro & cons on both sides. I love my Dodge Cummings diesel, but I also love my frugal Civic, but for different reasons!

Dave

[MetroMPG]

Originally Posted by Arragonis

If my comment comes across as uncivil, and reading it back maybe it does, then I apologise. Never post when you have just cut your finger on your first aero mod.

No apology necessary.

I agree 100% that a car is a better solution IF the truck isn't needed as a truck. I should post the link to Johnny Mullet's thread where he documents the financial payback of buying a second hand beater to offset his pickup usage. )

EDIT: here is is -
http://ecomodder.com/forum/showthrea...-big-4633.html

I was just concerned with the impression the original poster would have after getting two "short" responses in a row that told him to get rid of the truck rather than how to help him drive it better.

You post lots of good info and I appreciate it.

/end OT moderating issues... Let's carry on with the thread.

[99metro]

Another suggestion or two.
1. Keep your boost at or below 2 psi at all times (this will be a lesson in keeping a light throttle!)
2. When at a stop light, keep it in neutral til it is time to go. I see roughly 4 horsepower in neutral, but as high as 12 horsepower if i keep it in Drive while stopped.

I just did my all-time high trip mpg of 25.1 mpg by doing the above. Also neutral coasted as long as possible.