Bubble front plate covers? Anyone use?

Discussion in 'Fuel Economy' started by RoadWarrior222, Jul 20, 2014.

  1. RoadWarrior222

    RoadWarrior222 rockit serjun

    Hey folks,

    On my sleek shiny new Note, the one thing that makes me shudder every time I look at the front end is the 'orrible plate frame the dealer put on it. about an inch wide and standing half inch off the plate, a square edged fuel sucking monstrosity.

    So I wondered if anyone managed to record any actual difference between a regular plate frame or bare plate and one of those transparent "bubble" front plate covers, that at least LOOK like they should be a tad more aerodynamic.

    I guess I'm asking how long it will take me to save the $10 ... well given that this thing SHOULD have a 0.29ish cD and I'm doubting that plate frame is letting it get there, if they gained 0.015 ish with the grille shutter, I'm thinking that thing is costing me about the same.

    Another thought is that I picked up some similar but not bubbled flat plate covers a while back very cheap, and I could try heating one with a heat gun or over a hot plate and bubbling it myself.. (On a former, or with air pressure or something) and get a slightly bigger bubble than the $10 ones.

    your thoughts?


    Edit: Amazon product page for one similar to the ones I'm thinking of... http://www.amazon.com/Cruiser-Accessories-72100-Bubble-License/dp/B001DKSNI2
    Last edited: Jul 20, 2014
  2. MaxxMPG

    MaxxMPG Hasta Lavista AAA-Vee Von't Be Bach

    If the plate is centered on the bumper, the squarish shape isn't going to interrupt air flow other than maybe a little turbulence from air passing above and below through the radiator grille. Flow in any other direction will reattach to the front surfaces of the car before passing over, under and around the leading edges. When winter comes, you will be able to "see" air turbulence as changes in the patterns of salt that build up when driving in snowy weather. Clean surface means very little air contact, while higher velocity will show some streaking and turbulence shows as blotchy. I looked last winter at the front of my sister's Optima Hybrid (she has a front plate on it) and I saw very little indication of any real interruption of air flow. So I'd say front plates are ugly, but they're not interrupting air flow enough to justify spending money to address their shape. Also remember that there are many laws out there restricting license plate covers and even frames that block certain areas of the plate, so proceed with caution.
  3. some_other_dave

    some_other_dave Well-Known Member

    The conventional wisdom is that the back of the car is where the real aerodynamic gains are.

    The shutters are a bit of a special case, because the inside of the engine bay is really horrible, aerodynamically speaking. Lots of things sticking out, and bends, and impediments to flow. So if you can keep air from going in there, you gain more than you would just cleaning up the front a little bit.

    There's even a decent chance that the plate is in the "separation bubble" at the front of the car, which means that it has just about zero effect on the drag of the car overall.

  4. RoadWarrior222

    RoadWarrior222 rockit serjun

    I'm getting what you're saying, still looking like a square foot of drag parachute to me though. The question would be I guess, how soon it transitions from laminar to turbulent flow anyway, since it probably makes no difference whatsoever at 70mph+ because that would definitely be turbulent, but depending on how the area works, could dump me into turbulent sooner and make more drag around the 60mph mark than necessary.
  5. RoadWarrior222

    RoadWarrior222 rockit serjun

    Hmmm tried tackling the question through researching external ballistics of hollow tip bullets vs ballistic nose, but was finding too many rabbits trails, plus inexact discrimination between the bullets that actually have a divot in the nose or are flattened, and those which have a hollowed out inside nose, but with a thin ballistic shell remaining... this is because a lighter nose bullet has apparent ballistic advantages, that aren't necessarily aerodynamic in a sense that's useful to other bodies.

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