When driving a car, how do you know when to change gear?

Is probably seems obvious to many people but I kind of have a problem with that.

I tend to change depending on my speed...When driving a car, how do you know when to change gear?
its a mixture of many different things. But if you are a beginner the general rule of thumb to change gears for normal city traffic driving is around 2000-2500 rpms on your tach gauge. When you are merging in traffic or need alot of power for passing, then take the car higher in the rpms as long as you don't redline. The higher the rpms the more power your car will have. So if you don't need the power in the car then you always shift early in the rpms gauge. If the car feels like there is absolutely no power at all when you shift (the car bogs) then you are shifting too early. The more you practise the more you will know to adjust your rpms to shift. Then eventually you can just tell when to shift from the sound of the engine.When driving a car, how do you know when to change gear?
Speed, and engine sound
I do it between 2,000 and 3,000 RPM. This really helped me when I had the same question.



Now I am better at it and I'll wind it up to 4,000 or so when I need the power: this is rare though.
For a start, the sound of your engine should tell you. It'll whine or growl when you're going too slow!



Thinking of MPH, 1st gear (under 10mph) for pulling away and when you're as good as not moving, when you're above 10mph for 2nd gear, 20mph go into 3rd gear, you get the idea, and anything above 40mph for fifth gear.



If you're going up or down hills I suppose that depends on your car. Some cars can go up hills in 3rd, some can't even manage 2nd. If you're going downhill you could go into 3rd or above.



Depends on your car really, but these were the guidelines I was taught. :)
Depends on what stile you drive, but it's all based on rpm, not on speed. Of course people usually dont's watch their rmp meter, they just instictively change speeds based on things like the sound of the engine or the feel of the gas pedal.They don't even think about it. You'll learn after a while.



If you drive for performance, for the best acceleration, you wanna change speeds higher - close to the ';red line';, because with higer rmp you get more power out of that engine and into transmision. So don't be scared to get your engine screaming once in a while. It's designed to work just fine up to the red line for brief periods of time. But don't do it too often, because first you use a lot of gas with this style, and second you're overheating the engine and make it wear out prematurely.



For a economical style of driving, try to keep you rmp somewhere between 2k and 3k. That's the most fuel efficient range for a normal 4 cilinder engine. That means when your rmp approaches 3k, shift up. When it drops below 1.5k, shift down.



The real art for changing gears manually is to do it quick and in the same time to do it smoothly. Don't loose precious engine power while holding the clutch too long, but in the same time don't stress the gearbox by releasing the clutch too quickly.
Hello,



1. Learn about you engine. Try to get a specification of your engine (eg. peak torque and at which RPM is it). When you have a tachometer, just make sure that when you do a certain speed, you shift to the gear, which provides you the RPM range to match the band (say, 500 RPM) near the peak torque point. In this band, the engine needs the least effort to propel the car and around this RPM you have the best mileage.



2. You don't have a tacho: from the gear ratios of the gearboy of your car, and the final gear ratios of you differential and the geometry of your wheels, you can calculate, at which engine speed and gear, how fast your gar goes (approx.). This will give you an 'ideal speed' for each gear you have and you could try to maintain these speeds. When you have an RPM range, that will give a speed range for the gears.



Something like this:



http://pw1.netcom.com/~sgalaba/mph.htm



3. When go uphill, shift back to compensate increased engine load.



4. Expect two things when shifting (with constant speed):

- RPM will decrease when you shift upwards (watch out, don't shift up in higher gears when the RPM was so small that after the shift you go near below idle RPM, or you may stall)

- RPM will increase when when shifting downwards (don't shift back, when you have already high RPMs in the current gear, or the engine overrevs and the wheels may spin, causing handling problems)



5. You can brake by shifting down, but keep point 4 in mind.



6. When shifting up, try to rev up the previous gear so that after the change, the RPM falls near to the peak torque band.



If you have the opportunity to see at which RPM how your engine sounds, you can shift according to your ears.



Reards
it depends on which car you are driving.Usually I change gear when I feel that car have enough power to pull in next one.
the motor r.p.m,s tell you when to shift