I know they don’t have a grill due to not having a radiator and it being more aerodynamic, but replacing it with a flat sheet of plastic or metal doesn’t seem like the best way to go about it. If aerodynamics were the main goal wouldn’t the air that hits the nose make it less efficient? It makes sense to me to shrink down the front bumper as much as possible or create vents that give the air a more efficient path. Is it purely an aesthetic thing?
In: Engineering
It’s partly aesthetic since people expect cars to look a certain way and have the shape of a grille, also there is pedestrian safety laws that prohibit sharp wedge shaped cars.
Aerodynamics can be extremely, extremely complicated so it’s hard to give a blanket answer for all cars. For example, many of the first mass produced cards *look* sleek but [would have actually been more aerodynamic driving backwards](https://driving.ca/feature/1934-chrysler-airflow-aerodynamics-backward-wind-tunnel-test/wcm/af91c273-e9fb-4dc6-b373-f761a449629e/amp/). Having a blunt face isn’t necessarily bad for aerodynamics.
Car designs also have other factors they need to take into account – total car length so the car fits in a parking spot, for example, and also having a flat front can mean safer pedestrian collisions versus having the face of the car that could focus the impact into a smaller area of the pedestrian’s body.
Vents are also challenging because they need a path through the car’s body to direct the air, which may require making the car larger to have space to fit them and the other components. Bigger size means extra mass, which could make the car overall less efficient even in spite of making the aerodynamics better.
But also aesthetics can’t be totally discounted – car manufacturers make cars that they think people will want to buy. Some people like exotic looking EVs, but there definitely is a large portion of the buying market who wants an EV that looks like a conventional car even if the EV could be made far more efficiently without the constraints that designing a conventional car faced.
Yes, shrinking the front is better. However you still need a crunple zone, there’s EV drive system components in the front, and/or a frunk for storage. So you need something there.
In general, you are almost always going to be better off moving air around the vehicle than trying to suck it through the vehicle and expel it. Exceptions for stuff like a F1 car that has really optimized aerodynamics, but for most production vehicles it’s not worth it to invest any air that you don’t need for cooling, and EVs have way lower cooling demand (usually a <100 sq inch opening in the lower bumper is plenty)
If a brand has a shared platform for hybrids and EVs, a lot of times the simplest thing is to just give the EV version a solid grille. It’s better to deflect that air around the car than to ingest extra air and dump it out underneath.
If it’s a pure EV platform, then you usually see cars designed without grilles – Tesla for example does no grille, just a smooth front bumper with a slot at the bottom for cooling. I think they actually have some interior passageways that go through the bumper and into the wheel wells but I don’t know why.
As more companies make EVs on EV-only platforms, generally you see less of the “let’s just put a big piece of silver plastic over where the grille was”. They just have a small cooling slot and then curve the front edge of the hood lower down to improve the aerodynamics.
3 reasons.
-Consumers are used to the look, and designers aren’t sure what to do with the front of the car, since most of their brand identity is tied up in the shape of the grille (Especially luxury brands)
-A separate piece is easier to replace when the car is damaged
-The front of the car needs to be tall and rounded for safety, which doesn’t tend to look good if you don’t break it up with other shades, shapes, and colours.
To move gas powered cars burn gas inside a piston, which expands and pushes the piston outward. Of all the energy in the fuel, about a quarter of it ends up helping you spin the wheels and drive the car forward, most of it just makes warm exhaust gasses that go out the tailpipe. On the way out these hot gasses make parts of your car hot, especially the engine. The car needs to get rid of that heat or the engine will melt, so it flows cooling fluid through the engine. The heat is dumped into the air using a radiator which has the cooling fluid flowing through it and a bunch of thin metal films with a fan blowing on them to give lots of surface for the air to hit the metal with cooling fluid inside. Also as the car drives air gets pushed through the grill and into the radiator grill. If you drive faster and your engine works harder and needs more cooling, you also get more air flow into the radiator so more cooling.
Electric cars are very efficient, you don’t need a big cooling system because almost all the energy that comes out of the battery goes into pushing the car. So no need for a big radiator on the front with air shoving into it. You can just make the front smooth, which let’s the car drive more smoothly through the air anyway. Having a grill on the front slows you down, like swimming with a shirt on.
It’s to cool the engine via the radiator. It would be more efficient not to have it. EVs don’t have an engine in the front and produce much less heat.
I thought it was due to pedestrian safety requirements. Which actually apply to both ICE and electric cars. The idea (I think) is to prevent pedestrians from being tossed up over the front of the car.
Aerodynamics is more complicated than that. I don’t know what would be most aerodynamic for EVs, but it’s fair to say that the most obvious answer is not the correct one.
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