Aeromodding a 2021 Freightliner Cascadia

[freebeard]

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

[JSH]

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:



#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



#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.



#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.



#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)



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.

[j-c-c]

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

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

[JSH]

Originally Posted by j-c-c

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?



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


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/

[freebeard]

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

[j-c-c]

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.

[JSH]

Originally Posted by freebeard

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

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.

[Bigrigdave]

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.

[redpoint5]

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

[Bigrigdave]

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.