Questions tagged [car]

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16
votes
6answers
11k views

What limits the speed of a car?

From an engineering perspective, what limits the maximum speed you can reach with a regular car? I understand that some of the faster cars are for safety reasons limited to not run faster than say 250 ...
6
votes
5answers
1k views

Why do electric cars claim "instant torque?"

I was at a well-known electric car company today and they claimed "instant torque." The quote was something like the following: Driving this car is very different from a gas-powered vehicle. For ...
5
votes
3answers
1k views

Is it true that four-wheel drive is less efficient and if so, why?

I have heard many times that four-wheel drive is less efficient than two-wheel drive. Many car producers have a normal drive mode where only two wheels are powered, and turn the four-wheel drive on ...
5
votes
1answer
334 views

Proccess of a 4-wheeled vehicle taking turn

I have observed that when a 4-wheeled vehicle takes a turn, one of it rear tire moves with more speed as compared to the other. For example A car is taking right turn, its right rear tire will be ...
5
votes
1answer
88 views

Is there a way to estimate whether the driver or co-driver picks up the smartphone?

First of all, as I am new in this very corner of stack exchange please help me by selecting the correct tags! I'm interested in finding an alorithm, that estimates wether a phone is picked up from the ...
4
votes
6answers
1k views

Does the speed of Heavy Vehicles make more potholes

Should Heavy Trucks drive more slowly on weak (bitumen) roads to reduce potholes in the road surface? I am discussing with a feasibility engineer what causes more potholes. He says it is simply the '...
4
votes
3answers
22k views

What are those large cylinder "tanks" attached to the outside of trucks for?

I've noticed this a few times, the last time today: It's a big cylinder-shaped "tank" (for water?) outside of the front part of the truck. What's the purpose of this thing?
4
votes
3answers
154 views

How does my automatic car shift without complete temporary loss of acceleration

When my car shifts gears, the car's acceleration never goes to 0. I feel that there is constant torque to the wheels throughout the entire shift. How is this possible during a gear change? ...
4
votes
2answers
292 views

Six-Wheeled Mousetrap Car [Concept]

My classmates are making mousetrap cars to go 10 feet, and whoever goes the fastest wins. How a mousetrap car works is by attaching a lever arm to the snapper (the part of the mousetrap that shoots ...
3
votes
2answers
207 views

Why does "Google self-driving car"'s roof camera rotate?

I'm intrigued by this video in which the roof camera rotates continuously. One reason could be to capture 360 degrees around, but then again two cameras or more could do the same job capturing ...
3
votes
2answers
4k views

Friction clutch and the force required

I recently learned the basics of automotive clutches, more specifically friction clutches. Here is a simplified version of their operation explained to me (the car starts at rest): The engine and the ...
3
votes
3answers
177 views

Why rear wheels of the bus are covered?

There is an airport bus (Germany) which has it's rear wheels covered by the fender. Even front wheels have strange shape of fender around them (tilted toward front). What purpose of that?
3
votes
2answers
115 views

What is the percentage of direct workers in an automotive production plant compared to all the employees?

I am not asking for specific numbers of any production plant. I want to know the general direct worker/employee ratio of a plant. Example: if there are 1000 employees working usually 700 of them are ...
2
votes
2answers
184 views

How do hybrid cars achieve greater fuel efficiency?

In this question I’m comparing non-plug-in hybrid fuel/electric vehicles with fuel-only vehicles. Also, I’m not disputing that hybrid cars are more fuel efficient, I’m just trying to understand how. ...
2
votes
1answer
58 views

What standards exist regarding diagnostic systems in automotive engineering?

I'm designing a diagnostic system that simulates an environment and user input for a dummy vehicle. All possible critical situations are simulated in order to find out whether any errors are triggered,...
2
votes
3answers
296 views

Pivoting trailer gate on multiple axes

I am currently trying to design a rear gate to retrofit to an existing caged trailer (similar to image 3), with the goal of having a system where the rear gate can pivot down (on its bottom edge) to ...
1
vote
2answers
556 views

Passing by a semi truck on a highway

So I’m driving down the highway in my sedan on a speed of lets say 60 mph. Why is it that my car sways just before it passes or it passes me? Almost always where the semis first tire is (closest to ...
1
vote
2answers
62 views

Equal power transmission in 4x4 vehicles?

If a 4x4 (true 4x4 not AWD) has 3 wheels slipping, does the one tire with traction receive all the torque available from the transmission? Is there typically a reduction in power transmission in 4x4 ...
1
vote
2answers
72 views

How fast could a Mini Cooper go in a vacuum?

Lord Evulz just stole the Earth's atmosphere. Our hero must race his trusty old Mini - which he had already prepared to be airtight, to ensure the tires do not explode, with pre-packaged oxygen to ...
1
vote
1answer
36 views

Why do I need to place car cabin filter according Air flow label

in most of car cabin filters (for example MANN filter) I see that I need to place it according the "Air flow" label? But why I need to do that? What will be wrong if I will put it in opposite side ...
1
vote
1answer
25 views

Does a single-wheel brake intervention from ESC cause one wheel to be not brakeable by the driver?

Source: https://www.kfz-tech.de/Engl/Buchprojekte/HBremse/ESP3.htm Firstly, I don't know if this is the right StackExchange, but I will try nevertheless. Above I posted a picture of the hydraulic ...
1
vote
1answer
73 views

What wheel setup on a small, solar powered car, would have the least rolling friction?

We are attempting to design a solar car. The solar panel 4 1/2" x 13". I like to break these problems into their simplest form, in order to eliminate the least amount of possibilities. So, the goal ...
1
vote
2answers
76 views

Working out RPM from car engine's lb ft?

Using an old copy of an automobile magazine, these are the cars with hp and lb ft I am trying to work out the RPM for: 2007 Honda Accord 2.4 sedan, 2.4-liter 187hp 4-cylinder, 164 lb ft pulling power ...
1
vote
1answer
58 views

Similarities between OBD-II and VGA

I'm working on a project to make a Heads Up Display in my car. I need a way to present my project in front of my class, for I obviously cannot bring my car into the presenting room. My professor ...
1
vote
0answers
25 views

Standards for safety car seatbelts locking condition

Is there an (international) standard which determines the condition when a car seat belt locks? Which standard is it? Does the standard determines a speed in m/s of the belt, such that it locks if ...
1
vote
2answers
59 views

A few questions about cars

When I start the car, why do I hear the engine working when I'm not pressing the gas pedal? How exactly does the torque and power of the gears work? Torque = Radius * Force Power = Torque * Speed ...
1
vote
0answers
45 views

Would an afterburner on a turbine drastically improve acceleration lag?

A little bit of context. My friends and I were watching the "Dark Knight Rises" and a discussion about the Batmobiles ensued. I, being a former ME student, said it was stupid that batman has a turbine ...
1
vote
1answer
251 views

Physics of Trailer Hitch Height

I'm modifying a lawn tractor to pull single axle trailers in a woodland environment. They are rear wheel drive, have enough power, but traction is our biggest issue even when using tractor/ATV ...
0
votes
4answers
93 views

How is it possible that it took until the 1950s or even longer before they started using car belts and neck-supported seats?

I've spent a large amount of my life thinking back on past times, both long ago and "recently", meaning ~1950s to me. A lot of things make sense, but some things just fundamentally baffle me. One of ...
0
votes
2answers
30 views

Meeting point of turning wheels with rear wheels

I was watching this video about how steering on a vehicle. It states: If you track the meeting point of the left and right wheels, you can see that the meeting point always lies on the rear wheel ...
0
votes
2answers
53 views

Why does the synchromesh in manual transmissions act on the output shaft?

Wikipedia has a good animation of a manual transmission, but something irks me. If I understood correctly, in the animation, the input shaft is in green, and the output shaft is in cyan. The dog ...
0
votes
1answer
98 views

Why does a tractor not do wheelie with a lot of weight on the trolley?

Tractor carries more than his own weight on its trolley. The linkage between the tractor and the trolley is far away from the tractor. So, the whole weight of the trolley is on the back of the tractor....
0
votes
2answers
91 views

What should be the material and thickness of front pillars to stop car (~1,847kg and ~262 km/h) without killing the driver?

"Tesla Model 3 owner died in a tragic accident with a semi truck. The Model 3 went under the truck’s trailer resulting “in the roof being sheared off as it passed underneath,” which is known as a “...
0
votes
1answer
127 views

Calculating final drive force from engine torque and tyre spin ratio

Trying to build a simplified physics simulation for cars, along the lines of "Car Physics" by Marco Monster. I'm stuck at straight line acceleration. I don't know if I understand the ...
0
votes
1answer
56 views

What is the voltage at the ground electrode of a spark plug?

Since the voltage required to bridge the gap between the central electrode and the ground electrode of a spark plug can reach up to 40 000V and even more, my question is, how does the battery not die ...
0
votes
1answer
449 views

Why vehicle horns are tuned to consonant intervals?

The primary purpose of a vehicle (car, locomotive, etc.) horn is to warn other traffic units that something potentially dangerous is about to happen. And so, others must pay attention to the signal. ...
0
votes
1answer
28 views

How does Kia charge the high-voltage battery in EV mode?

I recently bought a Kia Ceed 2020 PHEV (Plug-in Hybrid Electric Vehicle). Its specs mention a 6-gear Dual-Clutch Transmission (DCT), a 105 kW Internal Combustion Engine (ICE) and a 44 kW Motor-...
0
votes
1answer
107 views

Determine if car is moving forward or backward

I would like to know if there is someway i can figure out if the car wheel is rotating in clockwise or anticlock wise direction. Im working on a project which determines if car rolled back on a hill ...
0
votes
1answer
27 views

Emulate normally closed relay with 2 normally open relays

Good afternoon, I have recently ordered a normally closed relay to fix on my car's daylight-running lights. When the main lights come on the DLR should switch-off. Unfortunately amazon has delivered ...
0
votes
1answer
30 views

Sonomotors, Sion: Can this electric car really charge up to 30km only from its solar cells?

Maybe you have heard about Sonomotors and its futuristic electric car, the Sion. If not, here is the link to its website: https://sonomotors.com/ Anyway, the manufacturer claims that this car can ...
0
votes
1answer
28 views

What is the fraction of power transmitted to the generator in full-hybrid cars?

In full-hybrid cars like the Toyota Prius, usually both internal combustion engine (ICE) and electric motor produces mechanical power to the wheels at cruise. But some of the mechanical power produced ...
0
votes
0answers
35 views

Calculation of the maximum car speed from the track [closed]

I have a track spec. A track is described by type (straight, left, right), length, and angle. I also have the full specification of the car. There is a program that, based on this data, can ...
0
votes
0answers
50 views

How come my calculated engine torque is so much less than the manufacturer's specifications?

Here are my calculations. Am I doing anything wrong?
0
votes
0answers
26 views

Frequency domain analysis of steering system of a car

Can anyone share the equations involved, or some relevant theory material for frquency domain analysis of steering rack and pinion using bode plot?
0
votes
1answer
51 views

Wheel angle for turning

Given a car configuration with a length of L and width of W. If you can give the top left wheel an angle of A to turn A degree how do you derive the angle of top right wheel for turning . I know that ...
-1
votes
2answers
106 views

Does lowering the ride height of a car 50 mm exactly lower the height of C.G by 50 mm?

Does lowering the ride height of a car $50\ mm$ exactly lower the height of C.G. by $50\ mm$ or is it higher?
-1
votes
1answer
56 views

What is pitch stability in cars?

Can reduction in pitching moment of a car be referred to as improved pitch stability? Or is this term strictly only with regards to aircrafts?
-1
votes
1answer
57 views

Does the shape of a car really matter for how much gasoline it drinks?

Let's say that we have a mid-1950s "gas guzzler". Now, we take away the exterior "shell"/chassis and replace it with a modern car's. That is, it will visually look just like a modern car from the ...
-1
votes
1answer
33 views

Why do all cars seem to use "reflective" paint?

I'm not just talking about "chromed" parts. I mean the whole "paintjob", which seems to be be designed to reflect the environment as to basically be a mirror (somewhat depending on the color). I don'...
-1
votes
1answer
44 views

Why HMMWV's lights aren't located at the edges?

Hummvee has front lights located far from edges, closer to each other. That makes it harder to see edges of the vehicle in the dark.