Aeromodding a 2021 Freightliner Cascadia
 

6 weeks ago a signed a lease to drive a truck pulling reefer trailers cross country. They pay a certain number per load for fuel, it I use more, it comes out of the pay line. If I use less it goes in my pocket

So here we are. I can't do too much crazy stuff but considering the 2023 is available with aerox package a la carte, I may buy some factory pieces, I may build my own.

So far I've been eyeballing the bumper extension/airdam but they seem susceptible to damage, wheel well filler trim pieces and my 10" side skirt extensions.


So far, I've found stated numbers of .25% efficiency increase with commercially available wheel covers for the rear. If my truck seems to average 8 mpg loaded, that doesn't seem enough for what they cost. Diy in process

Sorry I haven't been updating, although I have been at it. See updated photos.

My latest idea is to build a quick attach trailer tail. That's what the sketch with the measurements is for. I believe most of the trailers will have hinges in the same place so I'm considering a mount to them.

I thought about wheel covers for them as well but I'm sure I would forget them and the first time I have to drive back to get them it would negate any savings I may have from utilizing them.

Man, I'd get pretty crazy AB testing if I got to pocket the fuel savings.

Guess you won't be going in this direction
https://q4j8c2c6wsreh73d2o6m0w1a-wpe...Wheels-For.jpg

Welcome to the forum.

Welcome.

Do you know how to search the forum? It goes pretty deep.

Do you control the trailer, or are they rotated out? Here's something that relates to your use case:

https://ecomodder.com/forum/member-f...dynamics-c.jpg

Red, unfortunately I'm not a scientist, I'm not cool enough because I have a plastic bumper and a robot shifting gears for me

Free beard I've been lurking for 8-10 years. I'm pretty familiar with site functions thanks. Unfortunately I can have the same trailer for a few days or even weeks but the hope is to drop and hook at every stop. I have a sliding fifth wheel which I was hoping to slide all the way forward but weights do not permit.

All of the trailers have skirts and super single tires, some have 4 sided trailer tails, some have two sides but they're skirt always broken. The new trailers seem to have a two inch treatment along the lower middle of the door and a5 inch spoiler along the top and sides. I'll try to get some photos

Got it. Lurkers are important.

I don't care enough to search but there were wheel disks that expand like a crochet hoop to grip the wheel. Maybe they could be moved from one trailer to the next.

Probably an old hat to you, but Vekke designed smooth hubcaps for trucks/trailers some 11 years ago.
this is his thread: https://ecomodder.com/forum/showthre...cks-16478.html

and these YouTube videos seem to be most informative:
https://m.youtube.com/watch?v=nfbCXSkLiKA

https://m.youtube.com/watch?v=lqD3pXVmnQc

Covers are made of 3mm ABS sheet, iirc. The design is pretty straighforward, so you should be able to duplicate it, unless you are hopeless with jigsaw. I would try it for sure, if I were in youe shoes. smooth hubcaps are how much? 3 %?

Not the same one [IIRC] but just as good. :thumbup:

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A good tire pressure gauge and a long enough air hose to reach the trailer wheels. Properly inflated tires make a big difference when hauling heavy.

Oh, and a scangauge.


:turtle:

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Seifrob, thank you for the link and videos. Looks like I'm going to buy a jig saw.

Redneck, I have a gauge. I need to buy a hose and adapter.

Thanks for the ideas folks, keep them coming.

I'm looking at extending the side fairings and an air Dam/splitter.

then I remebered this one: https://ecomodder.com/forum/showthre...tml#post194036

I tried a search but all that it came up with is a competitive brand:
https://duckduckgo.com/?q=KOZAK+Aero...el+Caps&ia=web

https://truckcapnew.com/uploads/Whee...rs_02_wdff.jpg

It also uses a center adaptor instead of an expanding hoop.

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You may find this helpful.


NACFE

https://nacfe.org/


Current Technologies

https://nacfe.org/current-technology/


:turtle:

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I was really sold on the abs pop in style covers but I believe I ran into a problem as I have aluminum wheels and the u channel is not actually a channel on the aluminium wheel.

All is not lost, I removed one mirror, it's a curb mirror I guess. Above the passenger window.

It's the least obstructive of the mirrors but I'm considering removing one of the hood/fender mirrors as well.

🤔

Removing mirrors on a tractor trailer rig is never a good idea and those are critical blind spot mirrors. If you ever have to make a delivery, pickup or park in a tight place you’ll wish you had them and more. Damage the side of that new truck and your savings if any, will pale in comparison to the repair bill. And if it’s not your truck and your employer sees that you removed critical safety equipment you’ll probably be looking for another job.

A small car, motorcycle or pedestrian that can easily be missed with devastating consequences. Should something like that happen. You could be held personally responsible for a accident because of tampering with safety equipment by law enforcement. Then the lawyers…

The juice is not worth the squeeze…


:turtle:

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This is among the common internet fallacies, that accident insurance doesn't cover accidents.

I'll say something like I wired in my own outlet, and someone will say if my house burns down insurance won't cover it. That's precisely what insurance covers. If someone falls asleep smoking a cigarette and their house burns down, insurance covers it. Insurance covers accidents.

What insurance doesn't cover is intentional destruction. Douse the house in gasoline and light a match, and they aren't covering it.

You might look at DOT regulations before removing safety type items.

All these mirrors hanging out everywhere are a newer thing, probably a great idea. Drivers lived for years without them, but poophowdy, does it make doing some tasks slick and easy and beats getting out to go look. People that don't get out to look typically had damage somewhere.

I woul guess if you time constrained, they beat the wasted fuel they consume if you can even see it in the data plot

I am referring to the optional mirrors, there's one that seriously did nothing, and when you consider the Blindspot monitor system on this thing, I probably don't need the hood mirrors either.

I have large side door mounted mirrors with large convex mirrors in the same housing.

Upgraded my mudflaps.. then modified them.

They tend to shift in the brackets so you can see a 4 inch triangle parachute in the mirror, so now it's a 1.5 parachute lol

Next on the list is a 24" partial belly pan/ air dam combo.

Any OTR driver knows removing mirrors is flat out dangerous, If truck owner doesn't know about it, you are right his insurance will cover the accident, driver will be quickly out of a job, and looking at convincing a jury he doesn't warrant jail time if the accident causes injury.

The suggestion on max tire pressure is the biggest bang for buck after lowering speed.

Has OP calculated actual fuel costs savings to help verify what expenditures are worth investment costs, or is this just some wild fun experiment? If this owner operator is in for the long term, then it makes more sense of course. I'm not seeing it as a viable cost benefit project personally, other than the two solutions mentioned above.

That one air trick in an earlier reply showed a drawing of momentum trailer flap, it is not intuitive how that reduces drag IMO, anybody care to explain or tested it?

Please note, I have been adding/custom building aero tricks on my many commercial trucks since the gas crisis in 1974, most helped some, first one raised mileage from 5.6 to 7.8 mpg, I have been hooked ever since.

Absolutely just a wild experiment. I was able to take my 1986 Mercedes 300sdl from roughly 20 mpg to 38.8 a few years ago.

I then ran it on used engine oil, hydraulic fluid... Whatever I could get for free.

Flow below claims you can gain up to 2.23% with their tandem drive treatment kit, pictured in the attached image.

I modified my mudflaps to version 2.3 also pictured.

My partial bellypan did take me for a curve, I assumed the lip on the underside of the bumper were straight. I could possibly tidy it up a bit, but it seems to have tucked the bottom of the bumper up ever so slightly.

Sorry for potato pix
 

So, I removed my mudflap attachments for some ABA testing, down 1.1 to 1.4 mpg. I've been running Texas to Alabama for the past few weeks so pretty consistent routes.

May very well be 10-15 degrees cooler and more crosswinds but I don't like the numbers so version 3.0 it is.

I'll get some better photos in the morning.

I did remove the aluminum angle, it did some cool things in the rain but I don't think there was a positive drag reduction.

That might help. ...to explain whether it's down from 2.5 to 1.4mpg , or down from the 8mpg in #1 to ~6.75.

j-c-c -- I posted the pic at #3. That's the only place I've ever seen the high-momentum mud flap. Were I to speculate, it would run along the lines of a mudflap that curves forward at the outer edges to capture the wake off the tires and then collimate it into a central jet.

FlowBelow's claims are real but the Frieghtliner version are better.

Send me your truck number and I'll look up your spec and give you some ideas. (white sticker on the frame rail visible though the driver size front wheel well)

Update
 

I've been hard at work lately, seeing some much better numbers, just want to gather some hard evidence.

I guess my biggest upgrade has to be my wheel covers. $200, should be pretty quick to see an roi. The next cheapest option is 400+ and made of plastic.

On my third or fourth version of front tire spats? Maybe they're more of a tire dam. I utilize factory fasteners to mount things so without a super complex bracket, I've come up with a curved piece that seems to work best and doesn't look as out of place as the shark tooth 1.0 version.

So the skirts are about two weeks old and between all my mods, driving a lot more at 60-62 vs 65 and doing a lot more coasting, I seem to be up into the 11s with an empty trailer. This used to only be attainable with no trailer.

I will update next week or two once I have some more data

With the skirts half finished and the original tire spats, the black cut off triangles from the previous post, I did pull my highest weekly average.

I also was loaded much lighter than usual. 20k in the box vs the usual 38-44k. Which is why I'm waiting for more data and more loads to get some comparable data.

Last week's average 7.69 mpg
Previous week 6.2mpg
Previous best 7.2mpg
I believe that was the week I went home which included a 500 mile trip into Florida and 150 miles home without a trailer.

What, no roadwarrior spikes on the lugnuts? How about a windshield visor and dual exhaust stacks soaring into the sky?

Baby Moons on the front?

Free beard, I'm gonna scoop a set of these
https://raneys-cdn11.imgix.net/image...ompress,format
They fill the gap between the inside diameter of the rim and the face of the oil fill in the hub.
I don't imagine they'll make a measurable difference but I need to be able to inspect my wheel studs and nuts along with hub oil level.

I assume you mean these beauties
https://raneys-cdn11.imgix.net/image...ompress,format

I just need that peace of mind that my steer wheels are sorted at a glance.

Red. I don't need regular trucker accessories to show the world my inadequacy.

There was a thread that compared Moon, open centers and slots around the rim; and those open centers gave 80% benefit IIRC.

While I haven't had a chance look up your VIN yet your recent pictures tell me a lot.

#1 mod is to unbolt that huge bumper / grill guard and sell it to someone that wants to kill their fuel economy. It not only likely weighs hundreds of pounds but everything behind that is dirty air. This needs to go:

https://ecomodder.com/forum/attachme...p;d=1687511630

#2. Put the air dam back on or make your own to connect your wheel spats. Don't know if you had the 6-4-6 air dam or 4-4-4 air dam but lower is better. (Those numbers are ground clearance on the left, center, and right side of the air dam

This ebay one is odd. It shows pieces for the 6-4-6 but the 4-4-4- on the truck

https://i.ebayimg.com/images/g/PksAA...x9/s-l1600.jpg

#3. Reduce the grill intake size. You can make your own or use a commercial one designed for winter as a starting point. Of course this depends on terrain, temperature, and load but the factory grill opening is worst case cooling requirements: fully loaded, driving up steep inclines in death valley. Keep an eye on the temp gauge.

https://belmor.com/cache/images_cate...0_h500_q75.png

#4 Your side skirts are good. You should have had some from the factory.
Again lower is better, just don't let them touch the ground when aired down. (In winter they can freeze to the ground and then rip off or break your side fairings.) You can also close up the front wheel openings more like the factory has done. Close to the tire is better.

https://ecomodder.com/forum/attachme...6&d=1687640637

#5 Mirrors: You already mentioned you took off the door look down mirror. Removing the hood mounted mirrors will reduce aerodynamic drag a couple of percent. As you know but for others - the truck will still have 4 mirrors and be perfectly legal.

#6 Fairing extensions: Yours may help or hurt. The stock side fairings on your truck are more aerodynamic than the previous version that when full wheel to wheel. A lot of work went into getting the kick out angle right

#7: Cab extensions. The sides are optimized but take a look at extending the roof. (Some have this from the factory) You want as close as possible but still allowing turning with the 5th wheel adjusted forward.

#8 Fill the gap between the hood and bumper in the front. You could test with tape but Pipe insulation will be a more permanent solution. (Supertruck 2 has these)

#9 If you want to get real creative the next big aero issue is the negative area between the door and top step. You can look to Mexico for inspiration. Drivers there attach an extension to the bottom of the door. They do it to help prevent hijackings but the aero benefit is there too. (SuperTruck 2 has these too)

https://cdllife.com/wp-content/uploa...ft-768x513.png

Things that cost nothing: Keep your 5th wheel adjusted as far forward as you can and still keep the axle weights legal. The smaller the trailer gap the better. (Supertruck 2 has extensions that fold out at speed to close the gap and then fold back at slow speed to allow turns)

As mentioned above - keep you tires aired up

SuperTruck 2 is here if you are interested: https://freightliner.com/why-freight...supertruck-ii/ Some good ideas from a $50 million one-off truck.

https://ftl-media.imgix.net/truck/ro..._758x758-1.jpg

https://www.thedrive.com/news/new-in...ressive-16-mpg

Has roof mounted solar cells, wonder were they got that idea? LOL

Freightliner's Supertruck 1?

https://assets.newatlas.com/dims4/de...pertruck-3.jpg

Just kidding - International rolled out a really nice truck. They drew the card for hybrid trucks this go-around and they did a good job with it. There is a lot of tech that is realistic to transfer over to production commercial vehicles. Unfortunately mirror cams still aren't legal due to the NHTSA dragging their feet.

This is the truck in question for those that don't click mystery links
https://www.thedrive.com/uploads/202...=70&width=1920

Supertruck III was recently announced and here is what is going to be worked on. (Each manufacturer doesn't just go all-out, they are assigned different tech to use) https://www.act-news.com/news/u-s-do...-supertruck-3/

Don't the tractors have to take all trailers that come along? Or do they come in matched sets like that?

Since a lot of the gains here are with aero in this configuration, it's my guess this trailer solution will be part of a fleet and interchange will all matched tractors, there is also rear trailer axle braking energy recovery to batteries for the hybrid power system, which the trailer roof mounted solar cells augment.

That depends on the application. Some fleets own their trailers - some just move other people's trailers. Companies like UPS, FedEx, and Walmart own their trailers and only move their own freight.


The VAST majority of trucks on the road are owned by fleets. Owner-operators are less than 10% of trucks now.

I was going to wait on an update but I realized that I forgot to mention the 3 foot by 2 foot panel that I affixed to the lower trailing edge of the bumper. A partial undertray if I may.

Also added to the tire dams. Need to build a filler panel above them but I'm in the mid 9s with a combination that weighs 76k+ not bad.

I'm looking at front wheel covers and I may even replace my current rear covers with aerotech caps.

Jsh, thank you for your contributions. That Mexico idea definitely will be explored along with the roof fairing extension on the top. I pull reefer so I was a little worried about modding that area but I'm sure it'll be good.

Unfortunately I've seen way too many deer and don't like how much damage a modern truck incurs so the deer guard is a must.

I was considering the wheel cover included in the attached images.
2 things worry me, my wheels are hub piloted which brings up minor fitment issues but my bigger concern is with the shape of the vent hole. I believe two hole wheels have a larger oblong hole than what is on my Alcoa.

Maybe I'm splitting hairs here but I would think a cover that goes against the face of the wheel would be better than these smooth aero style ones I'm seeing that encapsulate the wheel studs and nuts as well.

Curious what the impact of the cattle guard might be? In general, front aero features aren't as impactful as rear.

Red. Unnecessary weight on the already heavily loaded steer tires will add rolling resistance to the aerodynamic complications so it would most definitely be beneficial to remove the guard.

I acquired the truck with this already installed, the fleet does not include them on the new trucks.. I'm sure they would charge me for it if it's gone when I return the truck at the end of the lease which will assuredly cost me more than any fuel savings.

Ordered some aluminum composite panel on Amazon. I'll remake that quick step delete on the passenger side as I never have anyone over there and depending on how that turns out maybe I'll make something for the driver side that will hopefully not kill me in a dark truck stop parking lot one night. I'm thinking a full block on the passenger side and maybe I'll make the driver side like the passenger side is now, the front half blocked.

I would love to mount it to the door so it's out of the way when the door is open but I just can't justify modifications that permanent.

Anyone with a freightliner like mine, those holes in the step are 3/16" so when I mounted the boot brush, I used pop rivets instead of the included bolts and nuts.