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Discussion Starter · #1 ·
I'm looking at options to modify the bumper on the XSE left and right false front air vents. When I say false air vents, it's because they are just solid plastic pieces.

Aftermarket products sold on ebay are DRL. But I'm not interested to put DRL. I'm more interested to fill in the hole because I believe this design is not aerodynamically sound. For example, the 2020, 21 Camry X/SE have a similar design/look. For the 2022 model, the plastic piece comes out more, meaning it's more flush with the bumper, reducing the dip.

I'm wondering if there's an aftermarket piece to fill it in. Another option would be to take the plastic pieces out and in turn this would allow more air flow in the engine compartment. On the other hand, this may make the bumper and associated areas including the engine compartment dirtier and faster.

Thoughts?
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Wheel Tire Automotive parking light Vehicle Car
 

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I'm wondering if there's an aftermarket piece to fill it in. Another option would be to take the plastic pieces out and in turn this would allow more air flow in the engine compartment. On the other hand, this may make the bumper and associated areas including the engine compartment dirtier and faster.
I wouldn't recommend just removing the pieces. Aerodynamics is tricky, and opening an air channel like that randomly is likely to create more drag, not less. There's a reason why the majority of the giant grill is blocked off.
As an aerospace engineer, I totally understand the obsession to decrease drag, but based on the rated and real life fuel consumption, I think any changes here is pretty negligible, so I wouldn't stress over it. However, here's probably the option with the best results if you're set on this idea: find someone with an LE/XLE/Limited of the same color to do a bumper swap with you (I'm sure there's someone willing to do the swap plus cash to get the XSE bumper), then use the cash to buy an aftermarket XSE-style grill (see my other thread: Aftermarket XSE-like Mesh Grill for LE/XLE/Limited)
 

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I don't mean to sound rude, or a smartass but I think you are overthinking this situation.
I think toyota engineers know what is and what is not aerodynamic. And calling a sienna aerodynamic is a big stretch, remember its a box with wheels. I believe toyota did everything they could to make it as aerodynamic as possible.
if you wanted to you could swap the front end with an XLE bumper to get rid of the holes in question but I don't think you will see an improvement.
Let's say you put 2k in modifying your bumper, what's your best scenario? I don't think you will see an improvement in MPGs. and if you do, it will be marginal.



I'm looking at options to modify the bumper on the XSE left and right false front air vents. When I say false air vents, it's because they are just solid plastic pieces.

Aftermarket products sold on ebay are DRL. But I'm not interested to put DRL. I'm more interested to fill in the hole because I believe this design is not aerodynamically sound. For example, the 2020, 21 Camry X/SE have a similar design/look. For the 2022 model, the plastic piece comes out more, meaning it's more flush with the bumper, reducing the dip.

I'm wondering if there's an aftermarket piece to fill it in. Another option would be to take the plastic pieces out and in turn this would allow more air flow in the engine compartment. On the other hand, this may make the bumper and associated areas including the engine compartment dirtier and faster.

Thoughts? View attachment 60654
View attachment 60653
 

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I think toyota engineers know what is and what is not aerodynamic. And calling a sienna aerodynamic is a big stretch, remember its a box with wheels. I believe toyota did everything they could to make it as aerodynamic as possible.
I'm actually quite impressed with the Sienna LE's drag coefficient of 0.28, given that it's basically the shape of a brick. The drag reduction primarily comes from the underbody covering, also the reason it's much easier to get a low Cd on an EV (no exhaust, etc, to ruin the smooth underbody). A van is also much better than an SUV because of lower ground clearance. For example, the more "aerodynamic looking" Highlander has a higher Cd of 0.34. The Sienna's Cd is actually comparable to many cars (Corolla, Camry), of course, the frontal area of the Sienna is huge so overall drag is still higher than a car with the same Cd (Drag = Cd x A).
The XSE does have a higher drag coefficient of 0.31, so Toyota engineers did compromise the drag for looks. But you are right that in the end the effect is pretty negligible given all the models have the same rated fuel consumption.
 

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I'm actually quite impressed with the Sienna LE's drag coefficient of 0.29, given that it's basically the shape of a brick. The drag reduction primarily comes from the underbody covering, also the reason it's much easier to get a low Cd on an EV (no exhaust, etc, to ruin the smooth underbody). A van is also much better than an SUV because of lower ground clearance. For example, the more "aerodynamic looking" Highlander has a higher Cd of 0.34. The Sienna's Cd is actually comparable to many cars (Corolla, Camry), of course, the frontal area of the Sienna is huge so overall drag is still higher than a car with the same Cd (Drag = Cd x A).
The XSE does have a higher drag coefficient of 0.32, so Toyota engineers did compromise the drag for looks. But you are right that in the end the effect is pretty negligible given all the models have the same rated fuel consumption.
yeah, I dont want to detriment what an amazing piece of tech the sienna is. I think they did a wonderful job and Im quite happy with ours.
I think that the way the sienna is, is the best scenario for fuel efficiency. Dont get me wrong, further generations will improve but for now it's as good as it gets.
 

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It's funny because I have the platinum and I noticed it doesn't come with those slits. I was thinking about changing. The one on yours makes the van look more aggressive and less like a soccer van. I am sure it affects aerodynamics. There is nowhere for the air to escape.
 

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Don't mean to interrupt your thread - but I might be able to help. I personally own an XSE and I have a build thread here sharing my journey and mods I'm doing to my own van. My company specializes in R&D and we do industrial-grade laser scanning, design and even produce end-use pieces. PM me if you're interested and let's see what we can do.
 

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Discussion Starter · #11 ·
Don't mean to interrupt your thread - but I might be able to help. I personally own an XSE and I have a build thread here sharing my journey and mods I'm doing to my own van. My company specializes in R&D and we do industrial-grade laser scanning, design and even produce end-use pieces. PM me if you're interested and let's see what we can do.
No worries. I forgive you, so long as you share your thread. 😁
 

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No worries. I forgive you, so long as you share your thread. 😁

I shared photos of our laser scanning at the bottom of page 1 and top of page 2, including wheel wells, OEM wheels, and measuring custom wheel specs.

We can definitely make new grill insert pieces for the bumper :)
 

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Do you have any interest or intentions to mod yours? If the price is reasonable, I would be interested. If a virtual image can be created. It would be nice to have it rounded out, a quarter circle to smooth the outer edge.
That would be one of the steps, correct. To make a 3D design so we can see how it looks like before it's made. Check your PM.
 
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