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The 5 Worst Mods You Can Make To Your Car: Aero Edition

If you're thinking of adding aero to your automobile, please don't. Chances are, unless you’re regularly running on a road course, oval, or drag strip and need the extra downforce and cooling that a proper aerodynamic setup provides, you're just going to be reducing your fuel mileage while increasing the volume of the laugh track that follows your car around town.

Even if you do take it to the track, aero that hasn't been intentionally installed and tuned either in a wind tunnel or through lap after lap of testing is likely to be more of a hinderance than a help, especially at higher speeds where drag starts to rear its ugly head.

Check out our list of the worst automotive upgrades you can make to your car: aero edition.

1. Wings That Add Drag

There are two types of wings out there: those that provide necessary downforce to the rear of a car that is traveling at a high rate of speed, and those that instead tack on so much aero drag that any downforce benefits are limited at best.

Wooden car wing

That little factory spoiler on the trunk of any recent performance car is designed to reshape the air moving around the vehicle, which often has the dual effect of making it more slippery (reducing drag) while also generating a small amount of downforce—as long as you're traveling at least 60 mph, of course.

The giant wing that you and your buddies made out of plywood/fiberglass/leftover aluminum siding, however? It's actively pushing airflow up and away from the trunk, and in doing so it's dragging a whole lot of air with it, ESPECIALLY at 60+ mph. Same goes for the super-expensive tuner wing that doubles as a standing desk for the officer writing up your speeding ticket.

Ugly wing

If you don't have access to a wind tunnel, it's going to be hard to know just how much that giant wing is impeding your progress—until, of course, it rips the rivets right out of your trunk lid and flies off to smash through the windshield of the car immediately behind you. That's probably 'too much' drag.

2. Scoops That…Add Drag

Once upon a time, a vented hood on a muscle car meant fresh air fed directly to the air cleaner, which was typically perched on top of the motor, directly in the middle of the engine bay.

Bad Hood Scoop

Today, electronic fuel injection has made it so that air intakes can be positioned almost anywhere, with the vast majority plumbed somewhere towards the front fenders where they can take advantage of oxygen flow coming in through the grille.

Terrible hood scoop

All that to say if you've attached a scoop—or two, or three—to the hood of your car but not bothered to connect it to the actual engine air intake, all you're doing is filling the engine bay with air and potentially generating lift (and certainly producing drag).

Bad Hood Scoop On Triumph

Gold star to those who simply slap a scoop on their hood with no opening whatsoever onto their vehicle just because it 'looks badass.' Two gold stars if said scoop is on the roof.

3. Air Vents On The Fenders

Did you actually cut a hole through your fender so that hot engine air could be sucked out, or did you simply use double-sided tape to attach a piece of plastic backed by chicken wire in a spot that may or may not be engine-adjacent?

Real fender vent

Shout-out to rear fender scoops that don't actually channel air to the brakes but instead dirty up the flow around the car for extra aero uncertainty at high speeds.

4. Dive Planes That Slice Your Ankles Open

Decades ago, you'd only find dive planes on nuclear submarines. Today, all you have to do is wander the parking lot of your local cars and coffee to unwittingly bang your calves and ankles into ultra-sharp carbon fiber winglets arrayed down the front fender of all manner of autos like some demented midget cheese slicer army.

Dive planes on a Nissan

Dive planes—also known as canards—are used on race cars that need to balance out the downforce effect of a big wing by moving the aero balance towards the front of the car. You need to be generating serious downforce at a high rate of speed before dive planes to anything more than act as very expensive curb feelers. Don't decapitate someone's pet while showing off at a sideshow, and leave the canards at home.

5. Splitters That Scrape Every Driveway, Ever

Dive planes are a relatively recent addition to the dumb aero toolkit, but chin splitters have been around forever. In high speed driving, a splitter performs roughly the same task as a dive plane (shifting aero balance forward), just in a different way (differential pressure between the top and bottom of the splitter itself). By keeping high speed air front piling up under a car, a properly installed splitter will reduce lift and improve handling.

Splitter on Nissan

Just driving around town, on the highway, or pretty much anywhere that isn't 3-wide at 150-mph, a splitter is instead going to scrap, snap, and shatter when it's rubbed against the uneven asphalt and concrete that form a typical commute. Even worse, the lower a splitter is to the ground, the less chance it has of creating the negative pressure required to improve downforce, which means a slammed suspension doesn't just mean a shorter lifespan for a splitter—it makes it totally useless.

What are the worst overall car upgrades you can make to your vehicle? We round up the most shameful car mods on the market.

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