Help To Understand

[Uditha88]

Hi Friends,

Please help to understand following.

1. For a manual transmission, U can have any RPM value for a given gear. Is it so?

Eg.

RPM from 1 to 9 for 1st gear

RPM from 1 to 9 for 2nd gear

RPM from 1 to 9 for 3rd gear

2. In automatic when "D" is selected, if we are going to have say RPM of 3, just after start moving,

transmission will automatically shifted to next higher gear which is 2nd.

So is it true if I say, "With automatic, you cannot have any RPM for given gear" ?

3. For manual, in following scenario,

RPM of 3 in 2nd gear

RPM of 3 in 3nd gear

In the above two situation,

a. Are the loads on the engine same?

b. Do both of the above consume same amount of fuel?

4. For automatic transmission, it's made like this

"Whenever the RPM is 2, it automatically engages to next higher gear"

Is this statement true? Else what would be the method?

Edited November 28, 2010 by Uditha88

[Uditha88]

Any Help Please...

[heavyD]

Machang, in an autobox, the car will choose it's gear not just according to rpm, but also taking into account how much gas you give it. So if you're crusing along in top gear at about 80 kmph and suddenly put your foot down, it's gonna shift down simply to get to the right gear and right rpm to ensure the most efficient power delivery.

Autoboxes shift up into higher gears sooner cause they're designed to work within certain speeds. For example, in my car, I can only shift to fourth (which is my top gear) after I've passed 50 kmph. That's cause it's designed to do that, to prevent stalling. Each gear has it's own low end speed cutoff. Similarly, I can never redline the car and keep it there, it'll shift for me. Like I said; it's got inbuilt safety features. I drive an auto/tiptronic btw.

I like to think of it like riding a mountain bicycle with gears. You know what I mean. If you're not in the right gear at the right time, you're gonna be overworking yourself, whether you're going uphill, downhill or even on a flat road. So for example, if you're driving in a high gear at a low speed in a car, you're probably gonna strain the transmission and the engine as well, and possible burn more fuel in the process.

That's my take on it.

[Uditha88]

Machang, in an autobox, the car will choose ....................

Thanks Big_D.

Hello other friends, Can u give me some other answers based on your knowledge please.

Mant Thanks.