What is overdrive and how should I choose between putting my car in drive or overdrive?
All the answers here are good for describing what overdrive does, but don't really give examples as to when you should use or not use overdrive.Most have said overdrive is good for highway use to reduce the RPM's of the engine and therefore conserving fuel. This is true as that is what it was designed to do.Additionally, overdrive would be safer in slippery situations where ice or wet roads may be a factor as the drive wheels would be much less likely to see a sudden acceleration from loss of grip.However, when do you not want to use overdrive?A good rule of thumb for this situation is to compare it to situations where you would find it beneficial to down shift in a manual transmission.These may include:When you are preparing to switch from a slower moving lane of traffic to a faster lane. Passing. Extended downhill grades, to prevent having to ride the brakes.Extended uphill grades to maintain power Hills when you are having trouble maintaining speed.Curvy roads where engine braking would be beneficial.TowingHopefully this helps.
What is that "+" and "-" sign on my car's transmission shifter? How do I use it properly?
It's the newer convention of the old numbers.For example, now we have:PRND - D+/-with some kind of indicator on the dashboard to display the selected gear.Whereas it used to be:PRND321and you just moved the shifter to the position corresponding to the desired gear.As for proper use? The car is designed to select the best gear for the conditions/inputs happening right now. The +/- allows the driver to "override" the computers choice based on other variables or future decisions that the cars computer may not be aware of. Here are some examples:Going down long hills, it's better to select a lower gear than to use the brakes to avoid break fade.Towing a trailer uphill, it's better to select a lower gear.Entering the highway or passing it may be better to select a lower gear.Driving on snow or slippery conditions it may be better to select a higher gear.It may also "switch" the car into a sport mode of some sort which will usually have adjusted shift points for a sportier feel.*selecting a lower gear means the same as the term "downshifting" more commonly reserved for manual transmissions.
Why do cars sometimes have the 3rd gear next to the "Drive" D gear? Why aren't the gears in order?
The shift lever on automatic transmissions generally works by limiting the maximum gear number that the transmission controller is allowed to automatically select. For many years, and in many cars still today, automatic transmissions had 4 gear ratios to select from. The “D” selection allows it to automatically range through all 4 ratios, which is fine for normal driving conditions; dropping it into “3” limits it to only the 3 lower ranges. Some cars have separate selections for “2” and “1”, or may have an “L” selection that encompasses both.So, putting “3” next to “D” does put the gears in order, with increasing restriction as you get further away from the “Park” end.
On the shift gears of an 2007 Toyota Camry what does 4-D,3 & 2-L means? Which one do you use to put in drive?
4-D is drive with four gears and the car will use all four gears when travelling, best fuel economy with 4-D and best for city use and long drives (motorways). L is for climbing a very steep slope or coming down to keep the car in control. 3 & 2 can be used in a light drizzle or rain for precautionary driving...
Why does my car jerk slightly when shifting into reverse?
all automatics do this. Regardless of gear the magnitude, the jerk is a function of drivetrain and suspension slop, clutch pressure and condition, clutch engagement setting, transmission fluid properties, idle speed.If the jerk is extreme and changes engine RPM by more than 100RPM, you certainly have a problem. beware, it’s easy to get either ripped off or spend heavily. Start by checking idle speed, then inspecting/changing fluid, then inspecting suspension. then check the transmission and drivetrain for slop, wear, damage, starting at a driveshaft shop.Your low mileage car could suffer from the hands of an abusive and jerky driver, a driver who spent long hours shearing transmission fluid stopped in traffic, or a transmission defect.Without mechanical service, you can reduce the jerk by not stepping on the brake as you change gears, and shifting to neutral every time you must idle for more than 20 seconds.
Is engine braking when going downhill bad for automatic transmissions?
You should use engine braking on automatic transmission when going downhill - certainly when it is steep or when it’s a long downhill travel.In the summer of 1998 I was a tour guide of a group of 12, split over 2 hired minivans (I believe it was a Dodge and a Chrysler). When driving out from Yosemite Park to Mono Lake, there is a downhill stretch of about 6 miles going down 2,000 feet.This is approximately 6%.Note: a lot easier to calculate in metric by the way (6% is 600 M on 10 km).The driver of the other minivan did NOT know how to use engine braking, and already halfway this downhill stretch she had to stop because of a “burned rubber smell”.This came from the front brakes. It was around midday, on a very hot and sunny day, and you could actually see the brake disc glowing red!A minivan loaded with 6 adults + luggage + camping material is very heavy and generates a lot of heat in the brakes. If she would have continued, she would have ruined the brakes and possibly have caused a serious accident.We cooled them down by sprinkling water on them, and I gave a lesson in downhill driving using engine braking :instead of setting it on “D”, you have to set it to “2” - or even “1” if it is really steep.The “2” setting will prevent the automatic transmission to switch to a higher gear than 2.Some transmissions even have a “3” setting. Others have an “L” setting, which switches to a lower gear.
Can you shift from drive to L in automatic transmission while running?
It is important to understand what shifting to L does to your transmission and what it is good for.This is what it does:It forces your transmission to use a lower gear. If your gearbox is in a higher gear, it will shift down. If your gearbox is in a lower gear, shifting to L will prevent the gearbox from using higher gears.This is what it feels like:The engine revs higher. It accelerates better. When you put your foot off the pedal, the engine brake effect is stronger - the car slows down.This is what you may need it for:When going downhill, you may desparately wish that your car does not become faster and faster, so you require a stronger engine brake.When in a hurry, you may want your car to accelerate quicker. So you want to avoid higher gears.When going slowly (in a parking garage) you may want to keep your gearbox from shifting up. This often is also desired when going uphill.In most situations it is no problem to shift to L while the car is moving. If you want to keep away stress from your transmission, avoid to use it as a brake. If your box has five gears and you think that 3rd gear does the job, first slow down the car with the brakes, then shift down the gearbox.
What is the I and L on my gear shift?
I own a 2005 Saturn Ion (Series 1). My gear shift doesn't have 1 or 2 at the end, but I and L. Now, living in Chicago, we have a lot of bad weather. I noticed when I put my car on I and drive slow (about 25 - 30 MPH), as opposed to D, I don't slide around in the snow/ice. My question is... what the heck are I and L and is what I'm doing bad?