I basjoosed my headlights today (sealed the surrounding gap)

[MetroMPG]

basjoos (v.) - to make aerodynamic optimizations at a micro (vs. macro) level.

(OK, yes, obviously basjoos does macro too, but whenever I start nitpicking about some small aero detail, I instantly think about his silicone-filled panel gaps. The "basjoosed panel gaps".)

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So, no, I don't have any pics to post yet, but today I bought a roll of 3 mm (about 1/8) thick peel 'n' stick weatherstrip because I was looking for a quick 'n' clean aeromod project to do before my next big one.

I fit the foam strip in the gap all around the driver's side headlight assembly. (I'll do the other side tomorrow.)

That gap ultimately leads into the engine compartment and under the car, so despite it being a small area, it's pretty much the top of the list in terms of where I don't want air to go unnecessarily.

I calculated a total open area of 43.2 cm2 around both lights, or 6.7 square inches.

Inconsequential? Mercedes didn't think so ("sealed joints on headlights"):



From thread: Mercedes modded C-class: Cd 0.25. Up 7.5 mpg over regular model (with other mods).

[azraelswrd]

Wow... 0.25 Cd. I wonder how much of that is because of the FULL SMOOTH-SURFACED UNDERBODY PANELING? Looks like they don't consider the hubcaps a priority, opting for weight over aero.

I never gave that gap much thought but now that you mention it and seeing that pic... you're making me a believer. I recently removed my ad hoc smooth hubcaps and rear skirts because they weren't having any effect on my routes but this sounds easy/small enough for me to squeeze in before I get back to my real job of schooling.

Does Prius have a "show me" diagram like that? I'd be interested in seeing all their upgrades, plus those from the Volt. Time to call upon the mighty search engine gods!

[MetroMPG]

Originally Posted by azraelswrd

I recently removed my ad hoc smooth hubcaps and rear skirts because they weren't having any effect on my routes

Really? Are you able to detect a change as small as a couple of percent above the noise of normal variation?

Does Prius have a "show me" diagram like that?

I haven't seen one. If you turn anything up, let us know.

[azraelswrd]

There was some slight noise reduction but it didn't translate to my scangauge. I will need more testing though under more optimal conditions. The wind lately has been annoying (HEADWIND???) and another reason I needed to remove all the tire tape was because I was getting my tires rotated today.

Got a lot of questions about my grill block though... blue tape does that.

[ChrstphrR]

When I was fixing my inner fenders on my TDI (replaced one, coroplast-patched the other), I noticed that I could see HUGE gaps between my headlights and bumpers. I ended up stuffing 1/2" x 7/16" weatherstripping into the gap below.

If I need airflow into the engine bay -- well, that's what the vents for the Radiator and Intercooler are for, not "extra" venting via the headlights.

No idea what improvement it's doing at this point, since I'm still calibrating my Scanguage II. That said, I know sealing that up that gap into a dead space shouldn't be counter productive.

[thebrad]

Originally Posted by ChrstphrR

When I was fixing my inner fenders on my TDI (replaced one, coroplast-patched the other), I noticed that I could see HUGE gaps between my headlights and bumpers. I ended up stuffing 1/2" x 7/16" weatherstripping into the gap below.

If I need airflow into the engine bay -- well, that's what the vents for the Radiator and Intercooler are for, not "extra" venting via the headlights.

No idea what improvement it's doing at this point, since I'm still calibrating my Scanguage II. That said, I know sealing that up that gap into a dead space shouldn't be counter productive.

I'd imagine the minor air ducting to the lamps is to dissipate the heat produced by the bulbs.

[MetroMPG]

azrealswrd: Ben suggested I use lime green tape for my temporary mods. Nuh uh. I bet your blue tape got lots of attention.

The fact that you thought it was quieter tells me that's probably a worthwhile aeromod.

ChristphrR: well, I did the other light this evening, and measured it. Total gap area (projected) around both headlight assemblies is 43.2 cm2, or 6.7 square inches - practically the size of a business card.

I figure: if I've got a business card sized hole smack in the front of my car that does nothing functional, and ultimately lets air into the aerodynamic torture chamber that is the engine compartment/underbody area, why wouldn't I cover it up?

GM obviously thought it was worth putting speed tape over the headlights (and other panel gaps) to squeeze max efficiency from the GM EV1 / Impact for its record setting speed run:



Will post pics of my weatherstripping mod in a few minutes...

[Johnny Mullet]

I seen that on Christine when doing the front grill block (bumper block) and was surprised at all the air gaps! I was not at all concerned with an entire blockage after seeing all this..............

[MetroMPG]

Pics:



Above: the gaps! It's no Lexus.



The 3 mm weatherstripping. I cut this in half, width wise.



This worked out quite nicely: the strip was just the right size so I could position it in the gap and peel the backing off with it staying in place. Then I lifted up on the bumper to squish the adhesive down nicely.



Top view: the hood presses lightly against this.



No more business card size hole in the front of the car! Mercedes, eat your heart out.

I need to finish the quarter panel gap around the side marker portion of the assembly. I'll just use black silicone there since it's too small for the foam strip.

[ChrstphrR]

Originally Posted by thebrad

I'd imagine the minor air ducting to the lamps is to dissipate the heat produced by the bulbs.

Hrm, well, maybe I'll clean out the car, and put a fire extinguisher inside. (My Dad and I both have the bad luck of having vehicle fires, anyway...)

And MetroMPG - nice picture showing the before, during, and after.

The size of the gap under your lights looks a lot like what I saw under my car (different make and all). I used a broken DQ Blizzard spoon to help shoehorn my weatherstripping under the lights, sticking it to the bumper fascia on the bottom, and sticking the top weather stripping to the plastic lense, again, like you did.

[wagonman76]

Nice job. And for very little cost.

My Celebrity has a pretty nicely put together front end, the headlights have virtually no gaps around them and everything is a clean look and is secure. The 6000, on the other hand, same year, has this front end that just looks so slapped together like a beginner high school shop project. Huge gaps, and nothing really lines up very well. Even the attachment of the grille itself is this hokey setup with these rubber clip things that rot, and these plastic clips on the sides that break off about every other time you remove the grille. Would probably be worth it and look better to just make an entire new solid grille for the 6000 out of coroplast.

[cfg83]

MetroMPG -

Thanks for the pix. I have some of this tape on the top of my headlights. My gap was so big I had to double-decker it. Now I need to take another look at the other places I can tape.

CarloSW2

[FunkSkunk]

I just did mine around the top of my headlights and I continued it up the side of under the hood. There is and even bigger gap that I actually doubled up on the weatherstripping to fill it.

[MetroMPG]

I was thinking I'd probably do the same thing. Looks like you found some better (thicker) weatherstripping than I did.

[FunkSkunk]

No I think it's the same stuff, I just had to do two layers for under the hood. Found the 1/2 thick stuff at Wal-Mart for about $2.50 a roll, I think Lowes has it too, but I'm not sure the price difference.

OH, and around the headlights I noticed there is a bracket for the lens, so I made sure to put a separate piece on that and cut out around the screw head just in case I needed to get it out one day. It wasn't as clean as I had wanted but it works for now.

I didn't even think about under the headlights! oh, and I noticed you didn't try to squeeze the weatherstripping in between the little notch and the inside of the lights coming up from the bumper, it was a pain but I got mine in there.

[FunkSkunk]

Just FYI, I'm jealous of your black bumper, It's really a pain in the butt trying to figure out how I'm going to cover up that stupid 'Schlick Quattro' bumper on mine without it looks ridiculous! (see pic in my garage)

[Intrigued]

Hey, before I try something like this...have any of you done much night driving with the weatherstripping on the headlamps like that? Back when I used to work for the GM dealership I saw some pretty strange things happen to things accidentally against a headlamp. I'd for sure want something with a high melting point - like the rubber strips the OEMs use...

Do some of those weatherstrips say "hi-temp"???

[saunders1313]

That is an interesting question. Although I don't do too much night driving I would still want to know if anyone has noticed anything. Also, has anyone noticed any difference in fe from doing the weatherstripping? How noticeable is the weatherstripping? I don't want my car to look like it has mods, I want it to look like it's supposed to be there.

[MetroMPG]

You won't be able to detect any fuel consumption difference by doing this mod. It was the equivalent of closing up a business card-sized hole in the front of the car. That's not to say it doesn't help a small amount, only that the effect will be smaller than the normal variation in your fuel consumption from other factors.

FYI, the weather stripping between the bumper and the light on my car has come undone and the foam has slid further back than I'd like. The double-sided adhesive didn't stick to the foam as well as it did to the paint.

I'm guessing this is due to heat - not from the headlights but from sunlight on the black foam/black paint. (If it was heat from the lights, the strip on top of the headlight assembly would have let go too, but it's fine - because it's shielded from direct sun when the hood is closed.)

[Intrigued]

I've seen the "adhesive didn't stick to the foam" issue with several different weatherstrips when trying to stop water leaks on different cars - after a while the foam seems to draw up, and leaves a sticky mess.

Still, I like the idea. Every little bit helps when looking for ultimate mpg, even if one particular idea doesn't show a measureable gain.

Hey, I just remembered something! Use something like a trunk lid or door weatherstrip. Maybe a piece of door w'strip or lip seal off an old car. Most of those are better with heat, and won't draw up. It'll look more professional, too. Rub silicone on the "face" to keep it from being pulled by whatever contacts it. I can't remember if the yellow or black w'strip adhesive works best, but maybe one of you guys do.