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Sat 16 Jun, 2007 01:22 pm
I just bought a 2007 Toyota Sienna. I notice the automatic transmission clutch has the following numbers/letters:
P
R
N
D
4
3
2
L
If I notice a hill coming up the road and I'm in the "DRIVE" position, do I shift to 4, 3, 2, or L?
In most situations, an automatic transmission will shift just fine without your interference. If you were going up a really, really, steep hill, with an extraordinary grade, you might slip it back into second--but that would likely only be necessary if you were climbing a long slope in the mountains on a crushed rock road, or another surface (such as just plain dirt or sand) in which you need to get good traction.
In almost all situations, you can just let the transmission take care of the gear shifting.
In the really old days (before WW I), as my grandfather told me, when the fuel from the gas tank was gravity-feed, people used to back-up long hills, because otherwise the fuel flow would soon die, and the engine would die.
So I would just ignore 4, 3, 2 and L and just keep it in the "D" drive position at all times? Even if the road is uphill or downhill?
that isn't what he said...
Under most circumstances, you can rely upon an automatic transmission to do the gear shifting for you.
Chai is right, that ain't what i said. Perhaps you should do some in-depth online research on automatic transmissions, and forget about me, since you obviously don't understand what i've written.
Quote:In almost all situations, you can just let the transmission take care of the gear shifting.
Isn't that basically mean that gears 4,3,2L won't be used in "almost all situations"?
It means that the automatic transmission is using those gears, rather than you using them by moving the gear lever. The transmission shifts gears, even though you just put it in drive and step on the gas.
Setanta wrote:It means that the automatic transmission is using those gears, rather than you using them by moving the gear lever. The transmission shifts gears, even though you just put it in drive and step on the gas.
Then why do the car's manufacturer give you the option of shifting to those gears when the transmmission shifts gears for you?
It's bad enough when people are obtuse intentionally, but it's impossible to deal with people who are being obtuse and don't even know it.
I'll explain this again, and slowly, and then i'm done. I'll try to be as thorough as i can, but if you can't figure most of this out for yourself, i wonder if you should be driving.
In most circumstances, the automatic transmission shifts gears without your help, and you can just put it in drive, and go. Your original question mentions the "clutch"--you obviously don't know anything about transmissions. If you have a standard transmission, the clutch is operated with a foot pedal on your left (in a left-hand drive car, such as are manufactured in the United States). In an automatic transmission, it is called automatic because the clutch is built in--you don't operate the clutch--and because it shifts gears in response to the rpm's of the engine. The clutch is a pressure plate which transfers the engine's revolutions to the drive shaft. By operating the clutch peddle, you release the pressure plate, allowing the drive shaft to spin freely, while the engine continues to turn over and spin the crank shaft in front of the clutch. You can then shift the gear, and release the clutch peddle, which allows the pressure plate to again make contact with the crank shaft, to again allow the engine to turn the drive shaft. In an automatic transmission, the transmission takes care of all of that. (If this is poorly explained, it at least comes closer to a reasonable description of what is going on than your question implies.)
There are, however, circumstances in which you might want to override the automatic transmission. If you put it in "Low" or "1," you can get very good traction, and very poor speed. You would do this if you were sinking into mud, or snow or slush. If you put it in "2," you get a combination of traction and speed, and this should be used on a muddy road, especially with a slope such as a hill, on an "unimproved" road (usually dirt) or on crushed rock, especially when there is a slope. It is the best way to drive in the mountains where there are often long, steep slopes and the roads are often of a poor quality.
The gears marked "3" and "4" would allow you to put it in a higher gear before the transmission would do so itself, so that you could accelerate faster than the automatic transmission is designed to do. You would almost never have any need to do this--it would be used almost exclusively by street racers (illegal) and drag racers (probably illegal, although it is done legally at drag strips).
If that doesn't explain it for ya, i give up.
On the principle that you will always better understand such things if you know more, from "How Stuff Works-dot-com":
How a standard transmission works
How an automatic transmission works
Both of those are introductory articles--there are links to get more detailed information.
I don't want to know how stuff works! All I want to know is what gear do I use when I go uphill?
Why is that question so hard to answer???
When you go uphill, do you think you'll be on a road?
If the answer is yes, you don't need to do anything other than put the vehicle into drive.
~~~
Your questions aren't difficult, Jeremiah, and the responses aren't that complicated. It does seem that you've got a vehicle that is beyond your understanding of normal driving practices.
But if you don't want to put too much strain on your car, don't you downshift if you go uphill? As oppose to putting the car in "D" drive all the friggin time?
Jeremiah wrote:But if you don't want to put too much strain on your car, don't you downshift if you go uphill? As oppose to putting the car in "D" drive all the friggin time?
NO.
Wow. This is the first time I've ever heard anyone asking how to operate an automatic transmission.
I'm going to make this very, very simple for you, and I really hope there aren't any other follow-up opinions to confuse you.
LEAVE THE CAR IN DRIVE AT ALL TIMES, NO MATTER WHAT.
Up hills, down hills, flat ground, bumpy ground. Leave it in "D." The car has a computer that will shift the gears for you. Up a hill, the car will use the appropriate gear.
"D" is not a gear. That means you're allowing the car to shift for you. It will utilizie all 4-5 gears. Putting it in "3" for example, means the car will not shift above third gear.
There is less than a 1% chance you will ever have to intentionally have to put it in a lower gear, and even in those situations, D will still serve you fine. I've driven hundreds of thousands of miles, and never used anything but D.
By the way, good choice...nice minivan(if you're into that kind of thing).
When driving uphill during hot summer days, do you turn off the air-conditioner to prevent the engine from overheating?
I'm planning to take my family from L.A. to Las Vegas the end of this month and just want to be prepared. I seen too many cars overheating and had to park their cars on the side of the road during summer...and I don't want that to happen to me.