38

It depends on the specific vehicle. Many modern standard transmission cars in the US have a clutch pedal sensor that will not allow you to start the vehicle if the pedal isn't fully depressed. You'll turn the key and nothing will happen. I've had older vehicles that preceded this sensor that could move the vehicle if the clutch was engaged and the ...


36

With the handbrake on, the rear wheel is not able to rotate. When the foot brake is released the car will try to move forward. This will cause a rotational force on the rear tire. Since the rear tire cannot turn, the rotational force will be transferred to the axle mounting point 'A' which will cause the road spring to compress, hence lowering the car body....


34

This is something that used to be quite common - in the '60s and '70s, people would add an electronic (or manual) overdrive to the back of the 4-speed gearbox to give an extra gear (usually two, as it would operate in both 3rd and 4th, although on many cars the difference between overdrive-3rd and direct-4th was very little). It's unlikely to be possible on ...


29

Most of the time you won't need heavy braking in traffic. You can avoid stopping and starting by: Driving more calmly Leaving plenty of distance between you and the vehicle in front (even at low speed) Simply taking your foot of the accelerator early If you let the car slow down, and use the gear until it is no longer appropriate (too slow that the engine ...


26

The lower the gear, the better the job the engine compression will do at holding the car if the brake fails, that's because a lower gear makes the engine spin faster and requires it to do more work for the car to move. So 1st is better than 2nd, between reverse and 1st it's not so obvious – but from the examples people are finding it looks like 1st is a bit ...


25

Being from Canada, I feel compelled to mention that if you do not depress the clutch while starting when it is at all cold out (let's say < 0 Celsius) you will notice the starter motor labouring significantly as it spins both the cold engine and the cold transmission. If it is really cold, your battery may not have enough power to start the car at all in ...


25

You've got several things wrong, as you've made a lot of assumptions. First, in an engine if the ignition isn't turned on (ie: if it doesn't have power), you cannot push start it. You can turn that engine all day long and it isn't going to start. Just won't happen. It takes fire to make it run, which in this case is a spark (we're not talking about diesel ...


24

Traditionally... The major drawbacks of automatic transmissions were: parasitic losses in the torque converter, something which manual transmissions don't have. fewer gears, so a given engine was more likely to be in its sweet spot with a 5-speed manual than a 4-speed automatic during regular operation. gear selection logic which was inferior to well-...


22

You can do this if your engine RPM, the speed of the vehicle, and the gear you are shifting to/from is just right. The reason you can do this is because you have synchros in the transmission which allows the two gears to match rotational speeds as they come in contact (basically, there is more to it than this, but hopefully you get the drift). The synchros ...


22

tl;dr: different gear ratios are a feature, not a bug. Some cars use more gears for acceleration, some use them for better gas mileage. You can't do both. At 3300-3500 RPMs, shouldn't the WRX be able to achieve better gas mileage by keeping the same 5-speed gear ratios, while adding an additional gear to lower RPMs to 2800-3000? You've exposed the ...


22

Manual transmissions (most, but not all) lubricate not through a pump, but through the action of the gears and secondarily through the level of the transmission fluid itself. In some transmissions, the lower gears in the transmission, which touch the pool of fluid at the bottom of the transmission, transfers fluid through contact to the upper gears. In this ...


21

A lot of new automatic transmissions (e.g. Volkswagen DSG) arent actually auto transmissions, at least not in the traditional sense. They have a normal computer-controlled dry clutch (well two actually) so they do not need to move around a lot of transmission fluid like traditional automatic transmissions do. Also they have a lot of gears (7, 8 or even 9 ...


20

Using the clutch engagement to turn the vehicle off can definitely hurt the car. Essentially what you're doing is wearing the clutch, bearings that lie within the motor, rings and valve seals. If you can visualize the physics and mechanics of what you're doing, it makes sense. When you let your foot off of the clutch pedal, you're pressing the friction disk ...


20

It could possibly work, but the better question is why would you want to test it this way? You'd be "grinding the gears" for no reason (even though it's the synchros you'd actually be grinding). This also would not provide a definitive "yes, my clutch is slipping" response. The reason for this is, even with a slipping clutch, in most cases the clutch would ...


19

When I'm on a hill with the front of my car facing up the hill I park the car in first and turn the wheels away from the curb so the transmission is fighting against gravity. When I'm on a hill with the front of my car facing down the hill I park the car in reverse and turn the wheels into the curb so again the transmission is fighting against gravity. ...


19

When you stop the car using the footbrake, all four wheels are held stationary by the brake. When you apply the handbrake, this locks the rear wheels only (in most cars) - as you then release the footbrake, this releases the front wheels, allowing them to turn ever so slightly. Gravity is still trying to pull the whole car downwards, and so it settles down ...


18

It is my understanding that electronic parking brakes remain in whatever state they were in when the battery dies or is disconnected. The electronic system does not "hold" the brake. It simply engages and disengages it. I would put the parking brake on and block the wheels.


17

Of course it's possible, but in an ideal electric car, you don't even need a transmission with multiple gears. The electric motor has a much greater range of torque/speed output at its disposal than an internal combustion engine does.


17

What it comes down to is there are trade offs. In the case of the engine, it's torque output and rotating mass versus engine speed ... read on. First, it isn't power which is needed, but torque to keep an engine running. In the early days of engines, each had one cylinder and didn't run very fast. To keep it running, it had a very large flywheel attached to ...


15

First, everyone who said that the braking effect comes from the compression stroke is wrong...the air in the cylinder is compressed which takes energy, yet after top dead center acts as a spring and helps force the piston back down, returning the exact same force as was put into it in the first place. Probably more, actually, since the compression heats the ...


15

Lugging an engine is like hammering the engine parts with every explosion in a cylinder. It racks on the rod bearing/journals, makes the pistons slap the side of the cylinders hard, and if is done enough, could probably break piston rings. It also creates a hammer effect all the way through the drivetrain. There are springs in the friction disk (of the ...


15

Reverse is pretty equivalent to first gear, for a ratio of around 3.2ish. If it were any lower, it would be difficult to get started from a stop since the torque just won't be there. If you've ever driven a stick-shift, try starting from a stop in 2nd or 3rd gear and you'll see what I mean. For example - ratios for my manual 5-speed 2007 Mazda6: 1st: 3....


15

Why can you not just shift to first and use the brake to keep the car from moving like all automatics in Drive, without touching the clutch? In a manual gearbox, the clutch (when you release the clutch pedal) is a 'hard' coupling that does not allow any slip. So the engine will try to move the car against the brakes, it will lose that battle (brakes are ...


14

They will probably work out to be the same. An automatic transmission is inherently more complicated which means more can go wrong and usually does (more so than manuals). The increased complexity also makes them more expensive, heavier, less fuel efficient etc. A manual transmission is less complicated which means there is less that can go wrong. Through ...


14

According to NY Daily News, only 6.5% of cars in the United States were Manual Transmission in 2013. That number may even be an overestimate. More helpful is Fix.com, which actually has a useful chart:


14

I'm not entirely sure a rev limiter will help protect you if you downshift at a speed higher than the gear you've selected is intended for. If you manage to lift the clutch, even without any fuel, throttle or spark, you could do some fairly significant damage. To answer the question regarding the rev limiter. If a carburetor or mechanical fuel injection ...


13

It's not something I've ever attempted, but I know people who have... The innards involve a lot of small springs, shims, etc (mainly in the synchros), and these can often have a habit of flying off when released! It is something that should only be attempted in a decent, clean workshop/garage so you can keep track of all the bits as you take it apart, and ...


13

It all depends on your definition of high. In my car, the red line is at 7500 rpm, and that indicates that driving with the revs over this line for anything other than brief periods is expected to cause damage, either through overheating, increased wear, increased loading on bearings, lack of sufficient oil/fluid flow etc. When driving I have to keep my ...


13

Until the engine starts the only thing applying torque to the drive train is the starter motor, the engine itself is not providing any torque. Starting like this will not cause any damage to the drive train (except perhaps the teeth on the edge of the flywheel that the starter motor engages with) but it does put excessive load on the starter motor and it's ...


12

A lot of newer cars are smart about shifting (they have electronic solenoids to control the hydraulics). I can put my 2001 Nissan Pathfinder in reverse at 50 MPH, and it's smart enough to not engage, it goes into neutral. However, at speeds below its cutoff point (I've done it at about 15 MPH and regretted it), you can put a lot of stress on the drivetrain ...


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