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Discussion Starter · #1 · (Edited)
After participating in a discussion, Not so Cheap Air Box Mod V3 started by @steve05ram360 and tips and encouragement from @'04CDT, I'm posting my recent trip from Birmingham, AL to Flanagan, IL.

Before leaving I taped the lower section of the front grill with a small hole to allow restricted air flow to the lower cooling system. Also applied tap to the gap between the cab and bed and taped the rear bumper that extends past the bed. See pics. I did a 2 test drives with the reduced air across the cooling system and cut a small opening in the front. I watched my gauges and A/C cooing. Also, MMX has a rad fan PID. The rad fan never cycled on the trip. Trans stayed between 175 and 180. A/C was ice cold, ran on low fan speed.

Trip to Flanagan, IL with stop in Mitchel, IN. I logged ambient weather/engine hours/odometer/Overhead (LOM) and number of stops as I drove. Worth noting, about 100 miles to Mitchel, IN was on hilly, curvy, 2 lane county roads. With the load it impacted my mileage.

Also worth noting, as I drove north, ambient temps dropped, IAT dropped and LOM dropped from 30.8 MPH to 30.2 MPG. The roads at this point were straight and gently rolling hills.

When on best MPG 3 injector pulse vs. single pulse, LOM MPG dropped. I've driven with 12V, single injector pulse, well over 150K. It always gets better mileage on a 12v valve tune.

Side Note: intuitively, Single Injector Events, reduce the number of injector events by 66% increases the life of the injectors. My OE injectors have +145K and all indications they are in good shape.

Overhead, LOM, was about 5 MPH higher than hand calculated.
Handwriting Font Paper Paper product Writing



First fill up was 60 miles of my destination. Hand calculated was 23.6 MPG.

Return Trip: No load in the truck. Rode much rougher, accelerated much quicker, cornered so much better. I filled up in Birmingham, AL. 25.6 MPG.

LOM continued to rise as temperature increased except the last 100 miles. They dropped about 0.5 MPG. When I got home, I noticed half of the front bumper tape and folded in, allowing air into the grill area.

Other notes, 23 engine hours, averaged 57 MPH driving. lowest ambient 68F, highest 85F. Engine 1840 RPM at 65 MPH.

Conclusions:
The following improved mileage: Aero mods, intentional driving, 65 MPH. IAT impacts mileage. 700 pounds and some curvy, hilly county roads reduced mileage by 2 MPG.

24.4 MPG trip average. Fuel cost $289.52

At 70 to 75 MPH the truck go 20 MPG. At todays fuel prices that would have cost $64.00 more in fuel and reduced my trip time by 3.5 hours. Each individual has their on pain points on fuel cost and time.

Reduced speed has proven to have less wear and tear on tires/brakes/suspension and generally safer.

MY 2006, 2500 SB, RWD, mods to improve handling, MPG and reliability:

Turbo Blanket
New, Wix, air filter, stock air box has some extra holes in the bottom
Tonneau cover
Tight suspension including: Fresh shocks, urethane bushings replacing all front end and leaf springs, rear anti roll bar, new ball joints, new U joint on steering column
2nd Gen, ported, air horn and deleted grid heater
Cummins T Stat
Replace ALL engine and fuel management sensors and relief valves
10W40 oil vs. 30W40
Taped lower front "grill" opening, air gap between cab and bed, rear bumper
12 Valve street tune, MM3, Rob
Fuel additives, 8 oz 2 SO, 8 oz ATF per 30 gallons
Single disk torque converter, performance valve body, shift pressures increased via tune

Automotive parking light Tire Car Wheel Vehicle
Tire Wheel Car Vehicle Automotive tire
Automotive tire Hood Road surface Automotive lighting Asphalt
 

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Discussion Starter · #4 · (Edited)
Man 25+ mpg over 600 miles is awesome. The best i have managed is the 25 in the sig but just 1 time and i milked every hill i could over the 200 miles on that tank. Warm day, warmer IATs and low speeds...
Some differences:
RWD vs.4WD
12V, single injection per cycle tune
Stock injectors/turbo, maybe, maybe not
Front grill blanked off
Tire size and type
Heater Grid
06 is better looking than 05 - :ROFLMAO:
 

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Discussion Starter · #6 ·
You can buy a 2017 Duramax 2wd and hope to get 16 mpg on the highway. But I suspect you like yours better. Good job.
Sometimes it's better to stick with the Devil you know rather the Devil you don't know.

16 MPG highway, I'd park it or Cummins swap....o_O
 

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Discussion Starter · #10 ·
OP. Great mileage. (y) Well done for that speed.
I've never gotten close to those numbers.
For now I'm used to my all around eighteen mpg.
Thanks
 

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Discussion Starter · #13 ·
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Discussion Starter · #21 ·
Great numbers!!

At exact 1,300-miles:

— 56.5-mph reflects reality pretty well (23-hours).

— 62-mph would have been the Average for doing 70 (if all Interstate; so 21-hrs)

— The “time savings” would have been under three hours as traffic volume interference increases the gap between Set Speed and Average Speed. It’s not just the aero penalty either:

A). Pull Out to Pass Penalty
B). Brake for Slower Penalty
C). Steering Penalty
D). RPM Penalty

— Steer more, change throttle opening more, use brakes more. Each adds to the aero penalty. And the above 1,900-rpm factor would also be at work. (Pull out to Pass is mental/emotional energy; gets one run down earlier in the day).

Two hour change is likelier. Over three is unlikely.

1,300-miles in (2) days is a fair truck driver test (seat cushion, hmmm) as it’s stretching the limits for the energy & awareness necessary to keep safe practice at highest level through a long day.

Perspective: we all do well to the 400-mile mark given adequate preparation. Past that is where White Line Fever sets in and our Reaction Time & Distance are worse. Everyone gets sloppy. (No exceptions).

MPG goes down during the day where all else is the same.

Q: How does one counter this?

A: Leaving earlier to spend less time in higher volume traffic as being alone is success marker for safe operation plus highest MPG. Truck and operator expend less energy.

If in a big truck given your 57-mph EH, “travel time” would be dead-on 13-hours with a 50-MPH Dispatch Estimate (0230 Departure) to have bought fuel at 1730.

1). Departure Time is crucial.
2). Timing of meals & breaks, same.
Energy to get in those last 250-miles is key.

— With respect, I doubt you left before 0430. Had you done so, the Average MPH would’ve been a bit higher given mainly Interstate. And a few tenths to the MPG. Don’t think this any kind of criticism, it’s to help you or anyone to think about a trip plan.

I’d say you’re feeling pretty darned good about bringing the CTD back up to par with the maintenance (some needed; some you got ahead on), the TLC (gap-covers), and the discipline to allow the CTD to do its best. Congratulations!

Debrief:
— The poly leaf spring-eye bushings are obviously a penalty when empty. Rubber (literally) absorbs vibration.

A). The counter is tire pressure where one doesn’t get below the Dodge Minimum (50-psi on my ‘04 RWD door placard). 50 is above the Load & Pressure Table Minimum (substantially).

— Second part is shock absorber design. I’d rather have a set of KONI on yours than BILSTEIN.

B). Higher than 55-psi (given scale weight confirms placarded use) won’t add enough to MPG to put up with a harsher ride, and that braking/handling/steering is about ideal (as is even tire wear).

The Ace:
PURPLE Ultimate Seat Cushion ($120-$150).

1). Can’t wear it out.
2). Eliminates all the cracks in the road.
3). Alertness seriously extended (no squirming around in seat, leaning towards one side or another to “get comfortable”).

(Shown without cover). Note recess for tailbone)

View attachment 953651

How good is it? I’m pretty sure I couldn’t drive a truck all day without it. (Old injury plus age-related health). And, at 6’2”, 200-lbs and in constant use since 2016 or so . . it won’t wear out. (I also use their Lumbar Cushion. Baby, I float on that seat!).

Truck drivers sit on air-ride seats in an air-ride cab on an air-ride suspension. My CTD is a more punishing ride at the end of a long day.

— Takes about a day to get used to it. Seat has to be re-adjusted to get best results besides ideal posture. Loose full-cut clothing, wallet in shirt, and knee-high compression socks.

Drive Wear lense sunglasses (prescription)


Summation:
— If that trip were to be run again, loading the CTD bed to about 1,000-lbs including the delivery item would give several hundred pounds on return trip to help with vibration-induced fatigue (given that FF/RR tires are at scaled safe minimum). And Ultimate Cushion (plus better posture, etc).

Best rest breaks & food stops plan is much easier when running a route the second time.

Experience Says:
— My trip-planning 24-MPG isn’t changed by up to 1,000-lbs as tested over a 47,000-mile stretch of flat terrain (but did include having to transit Houston every 350-miles).

At 1,200-lb bed load I could record the minor Gulf Coast difference. (Which would be magnified by hilly terrain).
Two-hundred pounds would be a minimum, 3-400 preferable, IMO.

Thanks, I would have never slowed down, concentrated on steering smoothly, etc.. without your coaching. I call it conscious driving! LOL

My air pressures were 50 psi front and rear. I left at 5:30 and didn't see many on the road until I reached Huntsville, AL. Nashville is/was has the most congestion.

1300 miles in 2 days plus time to unload and talk was a stretch for this 69 year old bod. I dressed for the trip. Loose baggy cloths, wallet in the tray, shoes off. I wear prescription sunglasses. Also carry a cooler with at least 2 meals going up. Drinking coffee and water.

I made frequent changes in the seat, using all the configs. I NEED one of those purple seat cushions! I'm going back to Flanagan, IL in October. I'll leave earlier, have a purple cush, lower tire pressure. The road expansion joints were tiring when empty. I drove around the pot holes as well, when possible.

I hope the P cushion helps cut down the shock load of the poly leaf spring bushings. I'll try it out soon. At the track, switching to poly or solid bushings yields faster times. OR in our case, better MPG averages.

My shocks have about 20K on them. Fronts: Rancho RS999279 adjustable and Rear: KYB KG 5196. After changing to poly leaf spring bushings, the truck stability change the most dramatically over any of the other mods. It tracks much better. I had been treating the problem with stiffer shocks, stiffer side wall tires, rear anti roll bar, poly front bushings, better anti roll bar end links, rather than addressing the rubber leaf spring bushings.

I changed out my rear brake calipers in the last 10K just because. I have a set of new front calipers I'll install with rotors and brake pads this week. Again, not because they are worn out, only 40K on them. I want fresh calipers rather that have the caliper stick and drag. I plan to change the calipers every 250K. LOL

Thanks again for your interest and sharing your wealth of information.
 
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Discussion Starter · #23 ·
I really need to get a 12v tune. Currently, the truck has EFI live by Firepunk and has their standard 5 tunes. However, they said they could replace one of the tunes with a 12v tune if I took it up there. They claim that their testing has shown no difference in mileage, which is fine because my main reason would be to make the injectors last longer. I know my truck won’t ever get near what you guys are doing since it’s lifted on 35s but I’d like to try to get more than the 15 or so it currently gets. I’m hoping to see an increase with summer weather and fuel. I’d like to get working on replacing the engine sensors too.
I had a 12V EFI Live tune before Rob's MM2 tunes. The EFI Live 12v tune always got better fuel economy than the other tunes, always. If Firepunks 12v tune won't get better mileage, at todays fuel costs, get another tuner. I'm very interested in how long my OE injectors last. IF 66% fewer injector pulses extend the life.

Sensors/relief valves, good grounds and battery cables are all part of the overall health of your truck and results in better starts and better economy.

Truck stability we talked about plays a roll as well. Cheapest mod that helps are the poly leaf spring bushings.

GL
 
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Discussion Starter · #25 ·
After chucking a 24v I cherish the quieter,smoother '07 I have. I heard a 12v tune the other day and it reminded my of my old '98.5.
I HEAR ya! Sometimes I've had enough 12ving and run a 3 injector pulse tune around town. On the highway there is not much noise difference between 12v and 3 pulse.

THEN, sometimes I LIKE rolling into the parking lot/driveway sounding like a 12v. Being able to switch on the fly gives us options.

12v tune is a little smoky. I get a puff on each shift. Tailgaters normally drop back a few car lengths.
 
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Discussion Starter · #27 ·
A co-worker had a 2wd SO auto qclb that never got more than 18 mpg and he commuted on the freeway to work 90% of time. Michelin blades. Conversely a friend had a qcsb NV5600 4wd w/37" and city/freeway beat that every tank. Speedo was adjusted for the tires. I don't know the axle ratio on either.
The older auto trans didn't have a locking converter or an over drive. Converter slip was from 3 to 8%, depending on the converter. It would be an interesting comparison to know what RPM he was running at 65 MPH.

There are so many other variables, driving habits, condition of the truck it's not easy to make direct comparisons.
 
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Discussion Starter · #37 · (Edited)
Follow up report:

I was changing out my front brakes today and noticed:

Wet spot under the truck. Upon inspection, my spin on fuel filter was leaking. I wiped off under the truck and turned the filter 1/4 turn. I'll monitor it more closely. No other leads, yeah!

Left front wheel bearing is going out. I thought I heard a rumble in the front. I'm not surprised. This is an OEM part, 245K on it. Timken ordered. Replace the right front awhile back.

Original front calipers are somewhat sloppy, rattle and crusty. New ones on order
Front left, inside, brake pad had less than 3/16". Only went 40K on these OEM pads, not Value Pads. I'm going with Bendix Fleet Metlok MKD965FM Brake Pads.

My 28' car haul trailer has changed how long my brakes and tires last. I finally got it tamed so it's not ruling my truck with load balance, load leveler and poly leaf spring bushings. Exhaust brake kit installed about 10K ago too.

Purple pillow ordered. Can't wait to see the difference. Like '04CTD, I set upright and normally close to the wheel. I moved my position about every hour or so. +23 hours driving over 2 days, my butt is still not the same!


I normally accelerated on the downhill side. Yes, I slow down and flash the big rigs in front of me. I passed only once, a big rig on a two lane road in IL on the return trip. His engine was smoking and he was running under the speed I wanted. Out in farm land, we had a LONG straight stretch to gently over take and pass.

On my return trip to Flanagan, IL this fall, I'll review this thread and apply the information and lessons learned.
 
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Discussion Starter · #38 ·
Its not 66% fewer events 100% of the time, the stock '05 tune does not use the post event after something like 1500-1600 rpms... I have it trimmed even further and it does not use it but in 8-12 cells below 1409 rpms. And... Ding, the bel just went off, lugging my motor is using all 3 events, should stop that.
Good info right there! Since both of my 12v tunes were locked, I'll never know how they were tuned.

My EFI Live 12v tune was not as cold natured as the MM3 Rob 12v.
EFI Live would start and run rough when the temp was below 30F. I stopped using this tune until ECT was above 100. It was smoker than the MM3 12v tune.

MM3, Rob, 12v tune automatically runs in 3 event until ECT is above 90F. Rob claims he has the "most" 12v tune out there. I don't know what that means. This 12v tune doesn't start smoothly even when the truck is hot. I start in a 3 event then switch over to 12v. When ECT is below 130 or so, 12v tune rattles. I don't hammer, if ever lol, when the truck is not warmed up on a 12v tune.

When switching from 3 event to 12v my boost gauge drops about 2 psi on the 12v tune. I haven't logged and compared 3 event to 12v tunes yet.

We will have a sample of 1, my truck, to compare how long OEM injectors last with ATF/2SO and a 12v tune! :D
 
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Discussion Starter · #40 ·
So, were you able to have Rob’s 12v tune flashed into one of the tune slots for your EFI live without changing the others or did you have to buy the whole tune package from him?
I bought the entire package. I wanted to upgrade my gauges from a 1st generation Edge. The MM3 DD was a nice upgrade. I didn't have a tune switch on EFI Live. I sprung for the switch on the fly option on MM3 as well.

EFI Live box is pretty much a paper weight if one changes tuners. MM3 is much, much faster processor and upgrade all the way around.
 
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Discussion Starter · #43 ·
RE: tapped lower grill opening... you can grab a 1500 bumper insert and modify it for the tow hooks... here is mine.

I LIKE that. I'll look for one. I'm thinking it may need to be removed when towing in the summer. Any thoughts on this?
 
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Discussion Starter · #45 ·
I never installed the retainers on the top (lower portion of the lower white bumper cover), with that said, it pops off quickly.
Nice to know. An aftermarket lower grill cover is about $45 in my hands. It's on the list. I have a few maintenance items to do first, brake calipers and wheel bearing.....
 
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Discussion Starter · #49 ·
Front wheel well vents... I wish I'd snapped a before pic, did not think of it. Here is an after pic of the wheel well vents on my truck after the install, note the amount of water coming out above the wheel and note how much is actually on the road. Next time there is a good bit of water on the roadway keep an eye out for a 3rd gen going in your direction and note how much water comes out of the top of the wheel well.

Hey Steve, we didn't get the pic. Please post it. Thanks
 
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Discussion Starter · #53 ·
I wouldn’t.

Air Dam 10” clearance to 7” a better choice.

It’s also my belief (can’t prove it) that rear fenderwell liners are a good idea re FE.

Covering the body-pinch to frame-rail space is going to do more than worrying over the truck front end. (#3, below).

View attachment 953753
Could use a variety of materials. I’m tending towards wanting to use expanded metal and overlay with geotextile fabric (atop; metal on ground-side).

Doesn’t have to be super-strong. It’s gonna get beat up, so easier R&R is a good thing


FE HIGHWAY GAIN

Will be about exit transitions

First up a box sits on tailgate to lengthen body in conjunction with tonneau cover.
View attachment 953766


Second is the real deal: an Aerolid

Here shown extended using a hitch receiver
platform and box.

View attachment 953767

Your truck interior db will drop enough you thought you installed extra acoustic treatment.

Dealing with headwinds or quartering b crosswinds, this will be what reduces counter-steering.

The nose of the vehicle is little compared to the flow interruption of the cab and how to re-attach flow afterwards PRIOR to exit.
.
I wonder if they listed these mods from most effective to least effective.

I've experimented with covering the grill on imports and my 2500 in the winter. We saw from 1 to 2 MPG gain. For a quick test, we used a stretch wrap material over the front grills. I made some grill covers for the truck and held them in place, behind the grill with zip ties. I just threw them away!

Fender liners removal may or may not improve MPG. Our testing on cars showed different results. Many cars today have vented wheel liners to help.

I just toured a vintage race car museum. These guys were all aero. The cars had full bottom aluminum covers. Even our mass produced cars today have plastic covers under the car to improve aero.

Wind tunnel tests have shown the front, where air attaches yields the most gains. We learned this when racing boats. We spent countless hours fairing the hulls. The entry point always got the most love.
 
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Discussion Starter · #54 ·
Big Dave

Air Dam Test plus comments.
GREAT READ! Thanks

Gosh, my old truck with some tape, 12v tune and driving techniques was not that far off the best of the best. 27 MPG vs my 25.6 MPG. I think if we put our more effort into it, we could best 27 MPH. Stuff like better driving techniques, ground effects and such.

To be fair, boosted, turbo charged, and diesel are more effect over naturally aspirated gas burner. :D

I'll clean up my experimental tape on the truck some and call it a day. Others can lead the charge.
 
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Discussion Starter · #58 ·
There’s at least one 2003 is at 30-MPG pretty much a factory fluke according to the owner (reported around 2006; a guy with a rep to protect)

At 58-MPH/1,725-rpm it wasn’t anything unusual I’d get 27-MPG on my cross-Texas commute circa 2009-10. Best high was 28.

I always filled at the same two places and in the same manner. No town miles in that. Straight highway. 325-miles. Same places to take breaks en route. (Trip grand total was 350-miles).

I use 24-MPG as the predicted fuel burn
(as it never dropped below that with adverse conditions).

My truck gets 24 is the fair way to state it.


— At 55-mph or a touch lower it was 30+. (Mine needs a touch of gearing help to bump that 55-58 rpm range to 58-62).

At 1,840-rpm you’re on the very edge of running the engine too fast. (I’m going to call it a piston-speed problem).
WOW!

All the above confirms our CTDs can be/are darn efficient trucks!

I haven't thought one moment what was limiting our MPG above 1850 RPM. Could be a combination of internal and external factors. I'm not going to hurt my head over this to much, just look for the sweet spot to operate.

We are building a naturally aspirated, push rod, V-8, Gen 3 Hemi. LONG stroke, extremely high piston speeds, 8,000 RPM. It will make between 2.2 and 2.6 HP/Cu In displacement at 8,000 RPM. As a comparison, street cars are making about 1.6 to 1.8 HP/Cu In at 5,000 RPM. Granted, we are not constricted with noise, pollution, pump gas, fits under a hood, etc. We have studied piston speeds as well as a hoist of other variables. Our CTDs have very low piston speeds in comparison.

There are so many variables, this could be a PHD's thesis and still not get it all.

I'm going to pick the low hanging fruit mods for my ol truck AND just might keep it awhile longer!
 
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Discussion Starter · #61 ·
Big trucks & Trains are looking for 11-M/S piston speed. CTD somewhere between that and a cars typical 14-M/S.

As cpitock noted yesterday, (paraphrased) the trans gears ain’t dialed in for it. (28-MPG thread).

The GP BSFC map firunderstanding.
View attachment 953779


The Dyno Room version (2003)
View attachment 953780


Wayne Gerdes running a 2016

View attachment 953781

The consistency is unforgettable.

24.4-MPG at 65 ain’t a fluke.

.
Big trucks & Trains are looking for 11-M/S piston speed. CTD somewhere between that and a cars typical 14-M/S.
This gas burner race engine we are building has a max piston speed of 45 M/S and average piston speed 28.8 M/S and making 33% more power than a 14 M/S. Piston speed IS important to engine life and one variable on efficiency.
 
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Discussion Starter · #62 ·
953779[/ATTACH]


The Dyno Room version (2003)
View attachment 953780


Wayne Gerdes running a 2016

View attachment 953781

The consistency is unforgettable.

24.4-MPG at 65 ain’t a fluke.

.
ALL the above is GOLD. Or $$ is ones pocket. Thanks for posting this!

I'm going to have a conversation with my tuner about improving his MPG tune and/or 12V. I know we left MPG on the table with both of these tunes. Rob has 2 12v tunes, standard power and Sporty Power. I have the Sporty Power 12V tune.
 
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