I tried looking online but have a hard time finding out exactly what the number on the gears of the car represent. What’s the difference between 1-3 or 2-5?
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The higher the number, the higher the gear. The higher the gear, the faster the wheels turn for every rotation of the engine/driveshaft, which means the higher the cruising speed. The trade-off is power; at higher gears, it’s harder to accelerate. Trying to accelerate from stop at 5th gear is horribly inefficient, if not dangerous to your car. But trying to use 1st gear to cruise at 50 mph will cause you to redline your engine and potentially damage it.
You should use low gears at low speeds and higher gears at higher speeds to keep your engine running at a safe “rate” (rpm) while keeping up with traffic.
In manual transmission 1 represents low gear and larger number represents higher gears.
The slower the car is going, the lower the gear that should be used.
The number doesn’t mean anything other than representing the order from low to high. Every vehicle implements their gear ratios according the function of the vehicle, weight, carrying capacity, the engine size/output etc etc. There is no fixed formula attached to any gear number.
The values are specific to the car model. They represent gears in the transmission of the car.
A transmission is a mechanical device that converts the rotation of the engine to rotation at the tires.
The numbers represent a sequence of gears from the lowest number of times a tire would rotate per time the engine rotates to the highest number of times a tire would rotate per time the engine rotates.
An engine at idle will rotate somewhere between 750 to 1200 times per min. That is called revolutions per minute or rpms for short.
A car typically when starting will be started in first gear it is not desirable to go have the tire spin quickly right away. As the car’s speed increases you use higher number gears.
Usually numbers above 4 represent what are known as over-drive gears. Where the number of times the tire rotates is faster than one turn of the tires for every turn of the engine.
This is a table for a 5 speed manual transmission from a Porsche 986.
In first gear the engine turns 3.5 times for every one rotation of the tire. 4 the gear is almost a 1:1 ratio and 5 gear is an overdrive gear.
1st gear 3.50
2nd gear 2.118
3rd gear 1.429
4th gear 1.029 G86
5th gear 0.79 G86
https://californiamotorsports.net/pages/porsche-986-boxster-transaxle-specifications
Imagine using a pry bar or a lever. 1st gear is the lowest, in pry bar term it gives you the most leverage at the cost of distance. You either have to lever really fast and risk burning out your motor/arm or you can move the fulcrum a little over to get more distance but require a little more force. This principle applies to gear ratio. These ratio are spaced apart like a 10 speed bike. So that you have a sweet spot between pedaling effort and speed. Pairing engine with transmission gear ratios allows car to move without stalling or burning out the engine. Because most engine wants to run at a specific range of RPM called the torque curve.
They are the gears, in order, from 1-5. So you shift left up (if you are American or European) for one, left down for 2, center up for 3, center down for 4, right up for 5, and right down for 6 if you have six gears. To get in reverse you normally have some trick so you don’t accidentally put it into first instead of reverse.
The numbers don’t really represent anything other than the lowest gear is 1 and the highest is the nth. The actual gear *ratios*, which is the speed of the output shaft of the transmission divided by the speed of the input shaft.
In a simplified transmission, the *output* of the engine is the *input* of the transmission. The *output* of the transmission is what turns the driving wheels. So, if I need to drive the wheels slower than the engine, I gear it down. Typically gears 1-4. Now I want to drive the wheels *faster* than the engine, that is overdrive.
The reason we need this scheme is that a car engine only makes torque in a very narrow band of RPMs. So I might need a really high torque at slow speed, like towing something heavy from a dead stop up a hill. In that case, I need the engine to rev up to 4500 RPM but I only want the wheels to turn whatever RPM equals 5-10 mph. I might need relatively low torque at a higher speed, like highway driving where I only need enough power to overcome wind resistance/gravity/traction. I don’t need that much torque, so I can slow down the engine but I need to keep the wheels fast.
You can ‘gear up’ a car simply by putting larger diameter wheels on the car, or gear it down by putting smaller wheels. It is the same basic principle, you measure speed by how many RPMs the wheel goes in a given amount of time. If your circumference is 100 centimeters, one RPM will equal 100 cm. A wheel that is 50 cm will only go 50 cm for one RPM. If those wheels both ran for ten seconds each with the same input RPM, the bigger wheel will be a farther distance away after 10 seconds, therefore it went faster. The input RPM didn’t change, the output speed (the distance measured along the circumference) *did change*.
A more technical definition of gear ratios is actually the number of teeth in the gear, more teeth means more diameter which means it is a bigger gear. A smaller number of teeth is a smaller gear. You can look at a Bicycle gearset, those are technically sprockets but it is the same idea. Assume one ring in the front and 9 in the back. The lowest gear is the rear chain ring with the fewest number of teeth and that would be 1. The 9th gear is the ring with the largest number of teeth and is the highest gear.
The numbers don’t actually mean anything in and of themselves. Low numbers are slow but powerful, high numbers are faster but have less power. The actual relationship between gears has nothing to do with the number of the gear (2nd isn’t necessarily twice as fast as 1st). It would be equally meaningful to assign the gears letters a-e but the convention is to use numbers
imagine the gears like the wheel on a tricycle, where the pedals are attached to the front wheel. a larger wheel will go faster and further for every pedalling revolution. a smaller one would make going up hills easier. if the wheel was too big, you wouldn’t be able to get going on a hill. and if the wheel is too small, you’d be pedalling too fast to maintain a decent speed.
on a regular bicycle with gears, the effective wheel size changes with the gears. a very low gear would be smaller than the tire size. and a very tall gear would be several times the size of the tire. the tallest gear would be impossible to start going on an uphill, and very hard to get going on flat ground. so imagine the tire size changes with the gears.
cars are similar in how a manual transmission or gearbox works. in most cases the engine is only functional between 1000 to 6000 rpm so you need a low gear to get going, and a high gear for better efficiency at highway speeds.
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