Hello, I drive a big truck and I like efficiency

[skyking]

Thanks for the update. I am still waiting on my new injectors, so I can do the next test tank. After I get the new baseline I'll do the fans and grille assembly.

[slowmover]

Nice post, genuninely so.

First thought as what to do is simple: records made easy (such as a smart-phone app).

Second is gauges: Pyrometer and Manifold Pressure

Third is SCANGAUGE

As to records, even irregular ones help. So fill out the fuel log and don't sweat it. I rarely of late fill my tank. Until I do I just collect receipts and records until I do fill. Then an entry is made.

I wouldn't at all both with trying to overfill the tank. Just remove nozzle at first click and be on the way (or install the TANK VENT MOD). Over thousands of miles the method of filling is irrelevant, as only the average mpg counts. I've never worried over it as it has nothing to do with what accuracy actually is.

Gauges -- whichever chosen -- give one an instantaneous readout.

As to other mods: I'd choose the MOPAR winter front, use the block heater, and add a KAT pad to the oil pan (and the trans sump plus rear axle). Don't know if anyone has done all three, but anything to reduce rolling resistance overall as a reduction of internal friction is on the right path.

For a highway-only truck, the aero mods would have preference.

Have you been keeping a log of average mph and average mpg? There is a correlation between a higher average speed and best mpg, overall. I find that under 27-mph (with my truck spec, climate and terrain) that this is the minimal number for "decent" mpg in around-town scenarios. Caused me to study routing for my most regular stops, and to improve it.

Records, report[ing gauges], rolling resistance, and routing is where I'd start (after baselining truck weights, brake drag, alignment, tire pressure, steering wander, CAC, etc. Have you done the 08 steering upgrade?)

.

[JustLuckey]

Slowmover, I completely agree with you reply. I will put a pad or something to jot down the info (odo, gals) so my wife can easily record when I'm not filling the truck. Ironically, it's time to fill it up tomorrow and I'll be the one doing it...so I'll have a good starting point. We've been driving it less, so that means I'll have a better chance of being the one that fills the truck.

As for gauges, I do have my BullyDog gauge/tuner that does show some of the important info, including instant mpg, avg mpg (both of which I calibrated and feel I'm within 1% accuracy), egt/pyro temp, fuel pressure, etc. I do keep a close eye on it when I'm driving and tend to drive more like a hypermiler than a race car driver. As far as avg speed, that's a tough one. When I make my big 800+ mile trip, then yes. I have a gps and can see my moving avg...but around town (and especially when my wife is driving) I do not have an accurate way to gauge it (since no gps is needed and my wife doesn't turn on my BullyDog gauge/tuner).

Regarding mpg and mph....I do tend to see the best mpgs when I'm in the 50-65 range (1700-1900 rpms).

I do have the block heater wired and use it when needed during the winter. I have looked at the MOPAR winter front, but haven't pulled the trigger on it (maybe this year).

I had a fuel tank heater installed (when I was making and burning biodiesel during the winter), but it lasted less than 1 winter before it started to come off. I could have put some of those huge zip ties on it to reinforce the adhesive backing, but, to be honest, I don't feel like running the risk of it coming (partially) off during the cold months here and have to work on it and/or repair it. Benefit vs. risk/maintenance is just not worth it in my opinion.

Thanks for the info. By the way, there's a guy on the cumminsforum that is claiming 27+ mpgs (consistently) with a 4x4 dually (hand calculated) and says his friends are too. Those of us following the thread are waiting for a reply from him giving some detail on his mods and his proclaimed 'kinks' that they have worked out for better mileage. So far, there has been no hard facts/stats to back any of his claims. I'm skeptical, but we'll see.

Here's the thread if anyone wants to follow it: (well, I tried to post the link, but apparently I need to have another post or 2 without links in order to meet quota. I'm not one to post something for the sake of quotas, so next time I post I'll see if I can attach the link)

[slowmover]

As far as avg speed, that's a tough one. When I make my big 800+ mile trip, then yes. I have a gps and can see my moving avg...but around town (and especially when my wife is driving) I do not have an accurate way to gauge it

Just use the "Lie-O-Meter" (overhead console readout) on a per-tank basis: divide miles traveled by elapsed time. This is average mph. When I say I do well with a 27-mph average it generally has little to do with road speed. Obviously, a highway trip will see a higher average. Once one learns how this works in determing fuel use (engine hours versus distance) it keeps one on the straight and narrow. The average falls off drastically with any extended idling.

I would start with the engine hours (see CF for how to find readout as I can't remember right now) and from that determine truck life average mph (as seen in my sig: total miles, total hours, and overall average mph). Make this part of your baseline. (See my signature).

As I recall, Cummins designed these engines with a 10,000-hour lifespan at a 35-mph average. MTBO, or B50 life. Right at 350k miles (unlike GM and FORD where 250k miles is the expectation [I believe the new Ferd finally meets the CTD B50 life design . . we'll see]). A truck with a 20-mph average may not meet that expectation: high hours with low miles, such as a city contractor. And a rancher some ways from town may exceed it with a high mph average per given engine hour. Etc. If 5,000-hours is the putative half-way mark, then I'd need to be at 195,000 miles. No guarantees of "extra" life, but I believe that what we tr to achieve around here is conducive to that end.

Prediction of what the truck can is central, IMO. Solo or loaded. Towing light, or towing heavy. Etc. Many data entry points to figure for accurate predictions. Average mpg & mph figure in for routing choices, terrain, climate and weather anomalies.

I have quite a few posts on CF in re FE. You could do a search under my screen name and the screen name Crabbelle [sp?] in a "post" search; he had a 2nd Gen DRW getting 30-mpg claimed. Pics, mods, etc. I found links to other sites in re his truck and experience. Not a 6.7, granted, but it may lend some insight . . and rebuttal.

.

[JustLuckey]

I just checked my truck. 121,321 miles @ 3,038 hours = 39.93 mpg. I'm going to make an honest effort to record my data and log it on this site.

[JustLuckey]

I have a ~400 mile round trip for work tomorrow and I'll be taking my truck. Although rain/snow in the forecast (upstate NY), so mpgs may not be ideal, but I'll fill-up when I return to start getting some data in the fuel log.

[JustLuckey]

Diesel Dave and others, I just logged my first 'official EcoModder' fill-up in the fuel log after a trip from home (PA) to Upstate NY. The previous full-up was stopped after the nozzel click off the first time (baseline), this fillup I did the same, to be consistent. 375.4 miles @ 16.84 gals = 22.29 mpg. Empty w/hard tonneau (I usually have the tonneau or cab high cap on)
I know fuel logging and tracking economy is a marathon not a sprint, but a good number to start off with. Next one should be down quite a bit as I've already hauled a bed full of split hardwood, and 2 trips to lowes with a decent amount of sheetrock...all city driving.

[Diesel_Dave]

Way to go. >22 mpg is a very good start. Don't worry too much about the fact that your FE is going to be worse when hauling stuff--that's why you got the truck.

Why don't you come on Team Cummins as our 5th member? Click on the "Team Cummins" below either my or slowmover's name and join.

[TX_Dj]

Hey hey, good to see some familiar faces here.

Dave and slowmover have been pestering me to join over here, so I figured I finally would...

Joined the team. MPG still pretty low (and will probably average much lower than the rest of you guys, just because I like to *play* with my truck) but it's coming up after the most recent round of work/upgrades/changes/etc...

Figured I'd check in and say hi, don't know how active I'll be over here, mostly wanted the fuel log graphs since they display much nicer than those in my smartphone app.

[slowmover]

Originally Posted by TX_Dj

Hey hey, good to see some familiar faces here.

Dave and slowmover have been pestering me to join over here, so I figured I finally would...

Joined the team. MPG still pretty low (and will probably average much lower than the rest of you guys, just because I like to *play* with my truck) but it's coming up after the most recent round of work/upgrades/changes/etc...

Figured I'd check in and say hi, don't know how active I'll be over here, mostly wanted the fuel log graphs since they display much nicer than those in my smartphone app.

Numbers "might" be a tad low, but your overall average mpg is said by one aftermarket tuner -- from their own survey -- to be the spot on CTD average. I consider it a "fair" number when looking over the national fleet (and the proclivities of the national driver). In other words, when someone asks what kind of mpg these trucks get, it's fair to say, they average 15-mpg.

Glad to see you over here. Living in a major metro area with its' 15-mph average city street traffic speed is the toughest hurdle to get over.

Thanks for taking the time to fill out the fuel log. The more of us, the better, in finding out what works over a wider range of use for these trucks.

his fillup I did the same, to be consistent. 375.4 miles @ 16.84 gals = 22.29 mpg. Empty w/hard tonneau (I usually have the tonneau or cab high cap on)

I'm not ever unhappy with 20-mpg. That I can, and the truck can, do better is lagniappe compared to the amount of work the truck can do versus fuel burn.
Suitably advanced engine timing and some aero work is really going to be "the thing" for highway deadhead miles.

Great start!

.