The Eco Driver.

Like it or not, if you drive a car, you’re doing harm to the environment. It’s an ugly compromise that most of us have come to accept. Sure, we value clean air, but we need our cars to get to work, to school, to the grocery store. The good news is, there are steps you can take to reduce your vehicle’s impact on the environment.

Smog Nation

Every day in cities across the country, we inch to work on crowded freeways, our windows rolled up to protect us against exhaust fumes. Problem is, we’re not really protected. According to the March issue of Harper’s Magazine, levels of air-pollution inside a moving car on an L.A. freeway are often 10 times higher than the levels outside the car.

As if the assault on our lungs and bronchial passages wasn’t enough, says Dr. Reed Noss of the Society for Conservation Biology, humans aren’t even the species worst hit by this pollution. Vehicles and the roads they drive on cause everything from immediate death to genetic deterioration, fluctuations in habitat conditions, and habitat fragmentation in wildlife populations. (For more on how roads affect wildlife, go to http://www.eco-action.org/dt/roads.html.)

Improvements

The Environmental Protection Agency (EPA) reports that, overall, national air quality levels have shown improvement for major pollutants since the 1970 Clean Air Act was signed into law. Nevertheless, in 1999, 62 million Americans reportedly lived in areas that had unhealthy air from at least one of six major pollutants: carbon monoxide, lead, nitrogen, smog, particulate matter, and sulfur dioxide.

Consider these facts:

• The biggest source of air pollution in a majority of the world’s cities is auto exhaust.
  
  
• Lead contamination from gasoline and tires has been found up to 100 miles from the nearest metropolitan area.
  
  
• Nine of the 10 largest multinational corporations in the world produce either automobiles or gasoline.
  

What Can We Do?

Slowly but surely, lawmakers are passing bills designed to reduce the impact of cars on the environment. Laws in California, for instance, now require that 10 percent of all cars sold by the year 2003 be zero-emission vehicles.

In response to laws such as these, America’s Big Three automakers–Ford, Chrysler, and General Motors–have formed the "Partnership for a New Generation of Vehicles" to encourage the development of alternative vehicle technology.

"This is customer-driven environmental responsibility," says Jac Nasser, Ford president and CEO. Now, instead of bragging about making the biggest and fastest vehicles on the road today, manufacturers are competing to make the cleanest.

Your Eco-Driver Checklist

Don’t wait for the politicians and automakers to solve the problem of air pollution. By following these tips, you can make your car a bit more environmentally friendly–even when you’re crawling along in rush-hour traffic. The three key words are reduce, recycle, and maintain.

Reduce

1. Reduce the time your engine runs

If you’re stuck in traffic for more than a minute, simply turn off the engine–you’ll save yourself some gas, and you’ll spare the lungs of the driver behind you. Also, if you live in a climate where temperatures never drop below freezing, it’s not necessary to warm up your engine for more than a couple minutes! Even in cold climates, today’s cars can operate effectively soon after start-up.

2. Plan your trips

For those of you who drive from one end of the mall to the other, remember:

• Walking is a virtue.
  
  
• Park where you can run several errands at once.
  
  
• Try to avoid driving during stop-and-go rush-hour traffic.
  
  
• Let your fingers do the driving–a phone call can confirm if an item you need is in stock, and catalogs and Internet sites offer car-free shopping.
  
  
• Before driving an extra 10 miles to save $5 on a pair of shoes at a discount outlet, consider the hidden costs of fuel and wear and tear on your car--not to mention the environmental costs. Is it really worth it?
  

3. Reduce the load on your engine

Anything that improves your mileage reduces pollution. Piling objects inside or on top of your car increases drag and reduces efficiency. Turn off your air conditioner when possible, and open a window instead. If you’re driving a standard-shift car, stay in the highest gear reasonable for your speed. If you’re driving an automatic and you have overdrive, use it.


4. Reduce your speed

I know, I know. You’ve heard this one so often it’s annoying, but remember: Reducing your speed from 65 mph to 55 mph increases fuel economy by 15%. Every time you increase your speed, you’re burning fuel and money.


5. Consider owning one car per family

Does every member of your family really need a car? Having access to only one car is a built-in incentive for both children and adults to bike or walk. When you do need an extra car, the mountain of money you save on car payments, fuel, and insurance will easily cover an occasional cab or car rental.

Recycle

1. Recycle used parts

Worn-out parts and discarded fluids (including batteries, oil, antifreeze, and tires) can often be recycled. Ask your mechanic or call your local recycling center.


2. Buy recycled

Always buy refined motor oil, and when you need to replace something like a starter or alternator, ask for a re-manufactured part.


3. Recycle your car when it "dies"

Don’t leave a dead car in your backyard! Even if you like the Sanford & Son look, it’s an environmental waste. Consider sending your car to an auto recycler (a.k.a. junkyard) where usable parts can be resold and the remaining metal crushed and recycled. Or you can donate your car to a vocational school that may be able to put life back into it, and you’ll get a tax deduction to boot.

Maintain


1. Maintain your engine

Cars with poorly maintained engines and emissions systems are the road’s worst polluters. Make sure a skilled mechanic runs an emissions-system check on your car.

2. Preventative maintenance vs. scheduled maintenance


Many cars today are sold with 100,000-mile tune-up intervals, but don’t be fooled. Even these cars need regular check-ups to prevent breakdowns and maintain efficiency.


3. Check wheels and tires

Have your wheels aligned–this reduces rolling inefficiencies as well as tire wear–and keep your tires properly inflated. Low tire pressure wastes more than 2 million gallons of gasoline in the US every day.


4. Prevent A/C leaks

If you’re having an older air-conditioning system serviced, make sure your garage uses a "vampire," a device that safely captures CFC coolants. Their release into the atmosphere damages the earth’s protective ozone layer.

Links

How does your car or tire company rate ecologically? Find out at http://www.responsibleshopper.org/.

For information on air-quality trends in cities across the nation, see http://www.epa.gov/airtrends.

Should dogs wear seatbelts?

The answer is, yes.

Recently I moved from Los Angeles to Tucson with my two greyhounds. The 80-pound male roosted in my Honda hatchback, which afforded him a great view of the landscape; the 60-pound female rode with my friend in a rental car, climbing between the front and back seats as she pleased. Both dogs seemed to enjoy the trip, and it was fun having them along to keep us company during the drive.

It didn’t occur to me until after the trip that I had put my pooches (and myself) at risk. What if I had slammed on the brakes? What if I’d been in an accident?

According to the National Highway Transportation Safety Administration (http://www.nhtsa.dot.gov/) and the Animal Protection Institute (http://www.api4animals.org/) there are no available statistics how many dogs are injured or killed each year in cars. Nevertheless, traveling pets face the same dangers we do, and they also pose a risk to passengers and other motorists. Author Stephen King was injured when a pick-up truck driver lost control while trying to corral his unrestrained Rottweiler.

Some U.S. lawmakers are beginning to catch on. The California Tether Law, for instance, requires all dogs in the back of pick-ups to be cross-tethered to the vehicle or protected by a secured container or cage to prevent them from being thrown, falling, or jumping from the vehicle.

But when it comes dogs and auto safety, the British are at the head of the pack. Drivers in England are urged to use seatbelt-like restraints on their pets or buy insurance to cover any damage or accidents caused by their passenger pets.

5 Reasons Why Your Dog Should Wear a Seatbelt

1. Distraction

Pets can provide much-needed distraction from the pressures of daily life. However, you don’t want your pet distracting you when you’re behind the wheel. The results could be disastrous--for you, your pet, and other motorists.

2. Impact

Pets without seatbelts are just like people without seatbelts: If you slam on the brakes or hit another car, they go flying. The last thing you need in an accident is a large dog hurtling at you from the backseat. It’s the last thing your dog needs, too.

3. Emergencies

A dog that has been in an accident is likely to be in shock, confused, and injured. She may attack rescue personnel without provocation. You can minimize this danger by properly restraining your dog.

4. Control

Even a well-trained dog can be distracted by a juicy squirrel or cat. If your dog is properly tethered, he can’t jump out the window or chase after another animal when you open your door.

5. Comfort

Imagine standing blindfolded in the back of a moving truck. Pretty unnerving, yes? That’s what the average car trip is like for your dog--a series of unexpected starts, stops, and turns. You can increase your dog’s security and comfort by providing restraints.



Restraining Dos and Don’ts

Do use restraints that offer mobility

Some restraints allow your dog only to remain in a sitting position. That might be fine for a quick trip to the post office, but over a longer haul, your dog should be able to sit, lie down, and perhaps stand.

Don’t put your dog in the front seat

The safest place for your dog is the middle of the back seat. Airbags are not designed for small children or dogs.

Do properly fit your dog with the correct size restraint

If the restraint is too small, it will chafe your dog and make her uncomfortable; if it’s too big, it won’t provide effective restraint. (Consult the links below to determine the proper size restraint for your dog. Most of the sites provide charts based on a dog’s chest measurement and weight.)

Don’t put your dog in a crate or cage

In an accident, a crate or cage will go flying through the air just like an unrestrained dog. Not good. And even if the crate itself is secured, your dog will be slammed against the interior walls with potentially lethal force.

Do ask questions about restraint products

Has the product been crash-tested? Safety-tested? Does the manufacturer offer testimonials? There are lots of companies that offer pet-restraint systems; find one that knows its product and stands behind it.

To Buy or Lease?

It's no easy thing to buy a car, let alone be a woman buying a car. Dealers are notorious for not treating our questions with the same respect they accord a man's. The best advice we usually get? Swallow your pride and independence, and bring along your boyfriend, your dad, or your brother.

In reality, you might be better off without the extra testosterone. According to Jack Gillis, a contributing correspondent for NBC's The Today Show and author of The Car Book (HarperCollins), women generally make better car purchases than men because we think we don't know a lot about cars, so we do far more research before we buy. And, strangely enough, we're less likely than men to make an emotional decision on the showroom floor.

No big surprise that we're better car buyers, but what about leasing? You've seen the ads: No money down! $199 a month! Thanks to lower monthly payments, you can often afford to lease a better car than you could buy. Leasing also allows you to get a new car every two or three years, and you'll have fewer maintenance headaches since major repairs are usually covered by the manufacturer's warranty. Leasing is safer than ever, too, thanks to the Federal Consumer Leasing Act, which went into effect in January 1998. This legislation requires companies to detail the fine print in their leasing contracts before you sign on the dotted line.

But while leasing seems like a great deal on the surface, it might not be the best option for you. Here's the scoop. With leasing, your monthly $199 pays for the difference between the price of the car and its value at the end of the lease period. In other words, you pay only for the portion of the car that you use during a two- to three- year period. At the end of that time, you turn in the car to the lease company like a pair of rented roller-skates, and you're free and clear.

(To make a short story long: The depreciation (or "residual value") of a car depends upon the model, the lessor (i.e., the bank or independent lease company), the amount of miles you anticipate driving, and any special promotions (such as a manufacturer's rebate). In most cases, the lessor, not the dealer, sets the residual value. The lessor also sets the interest rate, called the "money factor" or the "rent charge" in lease talk. This figure is usually expressed in a weird fraction, like .0038, which you must them multiply by the number of months in your lease in order to get a recognizable figure that represents your interest rate. So, if you want to find the best deal, you should shop around among different lessors.)

On the other hand, when you buy a car, you take out a loan for its full value, which translates into a larger loan and higher monthly payments. But once you've paid off the loan, you own the car: you can trade it in, drive it until it drops, or sell it. (Keep in mind that buying a car is not an investment. The value of a car will never increase with time, unless you hang on to it for decades and it happens to become a classic.)

Before you head down to the dealership to check out the newest models, take a few minutes to weigh your options:

The pros of leasing

- Lower monthly payments

Because you're paying only for the depreciation of the car over the lease period – the portion of the car you actually use – monthly payments are 30%-60% lower than you'd pay if you bought the same car.

- A fancier car

Because you pay only for the portion of the vehicle that you actually use, you can generally afford to lease a nicer car than you can buy.

- Fewer maintenance headaches

A manufacturer's warranty usually expires after two or three years. If you buy your car instead of leasing it, you'll have to pick up the tab for major repairs after that period. (Obviously, you should never lease a car for a period longer than that covered by the manufacturer's warranty.)

- Little or no down payment

A well-negotiated lease will have little or no down payment, but dealers often try to get you to put money down anyway. Don't do it. Remember, you're not buying anything, so there's no reason to "get it out of the way" early on.

- No used-car hassles

At the end of the lease, you don't have to worry about selling or trading in your car because you don't own it.

- Lower taxes

In most states, you pay sales tax only on your monthly payments, not on the entire value of the car. And if you drive your car for business, it's easier to deduct driving expenses, because rather than keeping a log, you can lease the car in your business's name.

The cons of leasing

- No equity

As you pay off a purchase loan, you build equity in your car, and after your loan is paid off, you can sell the car, trade it, or drive that sucker for as long as it lasts. When you lease, you don't own anything--you're essentially renting the car.

- Leasing is more expensive in the long run

When you buy a car, you have the option of spreading the cost over a longer period of time, and one day--when that loan is finally paid off--you'll no longer be making monthly payments. With leasing, you're always making a monthly payment, and over the long haul, it adds up to higher costs. For example, if you buy a car, pay it off in four years, then drive it for another four years, the cost of the car spread over those eight years will be cheaper than if you leased three or four cars in that same period.

- Excess wear-and-tear charge

Lease companies can charge exorbitant fees for little nicks and dings when you turn the car in. If you decide to lease, you'll have to be careful to keep the car in tip-top shape.

- Mileage limits

Leases usually have a 15,000-mile limit. If you go over the limit, you'll have to pay 10 to 25 cents (!) for each extra mile at the time you return the car. If you anticipate exceeding the mileage limit, you can often buy extra miles up front at a much cheaper price.

- It's expensive to break a lease

If there's any chance that you'll change jobs, lose your steady income, or leave the state, leasing is not for you. Breaking a lease is really, really expensive. Basically the leasing company is going to want all the money you promised them in the first place--except they'll want it all at once. A lease is a contract, with legally binding terms, and leasing companies usually don't like for the vehicles they own to leave the state. If you anticipate moving soon, you'll need to make sure your lease contract allows you to leave the state without having to pay a fee.

Deciding whether to lease or buy is only the first step in choosing a car. Next comes research. It's what we independent women do best, and there are plenty of resources on the Internet to help you calculate monthly payments, compare prices, and avoid dealer scams.

The Ageless Mechanic

My neighbor, Jacque Foreman, is graphic artist who enjoys working on cars in her spare time. These days, that’s not so unusual--more than one-third of all women car owners engage in some form of do-it-yourself car maintenance or repair. What is unusual is that Jacque is over 60 years old, and she’s been working on her own cars since the 1960s, an era when far fewer women ventured under the hood.

Jacque is the kind of gal who knows her way around a junkyard. Look in the trunk of her car and you’ll find spare parts, tape, a 2-gallon supply of water for radiator emergencies. Look in her purse and you’ll find tools. (Her most recent purchase, a tiny ratchet, has proven especially handy for the tight confines of her 1986 Toyota Tercel’s engine.) She is, according to her mother-in-law, the kind of woman who considers tools a fine birthday gift.

"You Drive It, You Fix It"

Jacque hasn’t always been a do-it-your-selfer, though. Once upon a time, she used to ask her boyfriend, Bruce, for help whenever something went wrong with her car. "He got tired of that," Jacque says, "so rather than just fixing my car, he started teaching me to fix it myself. His approach was, ‘you drive it, you fix it.’"

Was she annoyed by Bruce’s tough-love attitude? "No, not really," Foreman says. The only thing that bothered her was Bruce’s knack for diagnosing car problems so quickly. "The troublesome part wiggles at him and he finds the answer in minutes," she says. "With me, it just takes longer."

Jacque soon developed a curiosity for cars that has served her well. She recalls one night when Bruce had the engine of his Fiat 600 scattered in pieces on the living-room floor. (This was the early 1960s, shortly after they’d met, and they both drove Fiats.) As long as he was rebuilding the engine, Jacque insisted that he show her how it was done.

Bruce and Jacque have been married for more than 30 years now, and in that time, Jacque has become quite a mechanic in her own right. She still loves small cars, too, though these days, she’s partial to Toyotas, rather that Fiats and MGs.

Sometimes You Win, Sometimes You Lose

Car repair is a science of trial-and-error, and even good mechanics sometimes have bad days. Recently, Jacque found herself stranded on the side of the road.

"It never occurred to me," she says, "that after removing the thermostat, I wouldn't be able to get the radiator working. Tightening the gasket didn't help, and it wouldn't stop leaking--on me, and on the ground."

She ended up hiking to the nearest garage, which was very busy that day. "I politely asked the mechanic if he could tell me where the thermostat on my model was located, since it hadn't been on top as I'd suspected."

In the end, she still wasn’t able to get the car running. "To make matters worse, I was on my way to a Rotary Club meeting. That was one day I broke down and called a towing service."

Jacque, who pens the local Rotary's newsletter, later wrote a piece explaining why she didn't show up for that day's meeting. "I had expected to run in at the last minute telling them how I fixed it," she says. "It didn't turn out that way."

The Two Secrets to Auto Repair

It’s not often, however, that Jacque finds herself stranded. After 30 years of fixing her own cars, she’s learned the two secrets of auto repair--conducting regular maintenance and always being prepared.

These lessons were hammered home by an MG 1100 Jacque used to drive. When the car developed electrical problems, she and Bruce replaced all of the usual suspects--spark plugs, points, distributor cap. Still the problem persisted.

It wasn’t until they removed the distributor cap again and looked very closely that they discovered a tiny fraying on one of the ignition wires.

"Now I replace electrical wires every two years, whether they need it or not," Jacque says. "And I always keep the old wires with me in the back of the car, because sometimes the new parts you buy can be defective."

A Tale of Two Mechanics

I may not know about all cars, but I know mycar. I know the low grumble it makes when the air conditioning has been on too long. I know the sulfur-like smell that comes from acclerating too quickly before my engine is warm. And I know when something is wrong with my car--even if I don't know what that something is.

Still, it can be hard convincing a mechanic that I have a problem, especially with my limited garage vocabulary: "Well, it growls for a while, and then there's a little ping."


That's what I said to my mechanic in Liberty, Missouri. Almost immediately, I felt a dislike for him--the way he raised his eyebrows, the sarcasm in his voice as he repeated "little ping" and grabbed my keys. Before he even got into my car, I could tell he thought I was dingy. Which is probably why he drove around the block only once before he determined the car was fine. "I don't hear nothing," he said.

I don't like feeling unsure of myself. As I drove away, I played with all of the buttons on my dashboard, trying to see if the noise was just the air-conditioning or a bad stereo connection. By the time I got home, I'd let that guy convince me that I was, in fact, hearing things.

Of course, the ping got louder over the next few days, so I took my car back to the shop, only to get a repeat performance of our prior meeting: "Nope," the mechanic said. "I don't hear nothing."

Eventually, the ping got so loud I could hardly hear the rumble. I knew I was going to regret it, but I took my car back to the mechanic once again. After another five-minute drive around the block, he had the nerve to tell me, "Look, there's no ping. There's no noise. There's nothing wrong with your car. Stop coming here."

That was a Wednesday.

On Sunday, my car broke down while I was taking a friend to the airport. I barely made it to a service station. I spent more than $400 on a problem that my new, really great mechanic said could have been diagnosed "by any idiot."

You better believe I never gave that first mechanic any more business, but I did stop by to show him my new engine parts and my expensive receipt. I was steamed and I let him know it. I made sure none of my friends went to him, either. Since that incident, I've come up with a set of guidelines for choosing my mechanics.

1. I must be taken seriously.

How could that mechanic not take me seriously when I was spending more than an hour each day in my car? Now, when I say words like "hiss" and "gurgle," the mechanic better say, "Where's this hiss coming from?" or "How loud is the gurgle?" If they laugh or joke about my description in any way, I have no problem walking out the door. And if I hear anyone back in the garage using words like "bitch" or "blonde," well, that's all the more reason to leave.

2. The shop should be independently owned, not part of a chain.

Okay, so this requirement has more to do with my politics than my ability to detect a woman-friendly mechanic. Nevertheless, it's no secret that independently owned businesses live and die by their reputations. If an independent shop owner wants to survive, he has to treat all his customers respectfully. Plus, I've found that mechanics at independent garages are sometimes so grateful that I didn't go to the Jiffy Lube down the street, they'll throw in little bonuses--like filling up my fluids for free.

3. The mechanic must be honest.

Above all, my mechanic must be honest and never try to take advantage of me. I look for the following traits when trying to determine whether I'm dealing with a trustworthy repair shop or a gang of sleaze-balls:

• They ask my permission before fixing any problem.
  When I go in for routine maintenance, they don't try to sell me any additional, unnecessary services.
  
• If they do find additional problems with my car, they let me know how long I can expect to safely drive the car instead of urging me to get the problems fixed immediately.
  
• Other women get their cars serviced by the same mechanic.
  

There are great mechanics out there. It's true--I've got one here in Cincinnati. He doesn't talk much and he's pretty greasy, but he knows my name. And most importantly, he knows that I know my car.

"Wash Me" Six Secrets for a Perfect Do-It-Yourself Car Wash

Have you ever come out of the mall or the grocery store to discover that some clever kid has taken his finger to your car, leaving a message in the layer of grime. "Wash Me," it says. Or even worse: "Don’t Wash Me. I Belong to Pigpen."

That’s when you know it’s time to do something about those dusty windows, water-spotted chrome, and mud splatters. But before you zip over to the $1.50 automatic car wash at your local gas station, you should consider doing the job yourself.

Do-It-Yourself Is Best

According to Mike Hargrove, a professional detailer since 1974 at Mercedes Benz of Cincinnati, there’s a good reason your dad spent so many Saturdays in the driveway with a plastic bucket and sponge, soaping down the family sedan. It’s the safest and most effective way to wash your car (aside from a pricey professional detail job).

"Only you know how much pressure you’re putting on the car," Hargrove says, "and when you hand-wash, you can control that. Less pressure means less damage to the paint, and a better finish over the years."

Six Secrets for a Perfect Car Wash

1. Since pressure and friction are the enemies of your car’s finish, Hargrove says it’s crucial that you use a soft cloth, such as chamois or an old knit rag or T-shirt.

2. Pick your detergent with care. It’s fine to grab the liquid dishwashing detergent out of the kitchen for your Saturday afternoon hose-down, but be aware that the grease-cutting properties in that detergent will gradually strip off your car’s wax. Unless you’re planning to wax after you’ve washed, purchase a grit-free commercial car detergent, the milder the better.

3. When buffing out fine scratches, use a buffing compound with as little grit as possible. Heat, not abrasion, is what will restore the fine shine to a coat of paint, Hargrove says. The shiny finish on your car is the result of a "clear coat" over the manufacturer’s paint, and the heat generated during buffing causes that clear, protective shield to relax and smooth out, giving a beautiful shine.

4. This may sound like a no-brainer, but dark-colored cars require more frequent upkeep than light cars. Owners of dark cars should buff and wax at least 4 times a year to maintain the depth and shine in the paint’s finish, because the scratching and wear of daily driving and weekly washing will show up faster on a black or brown car. Lighter cars–tans, light blues, whites–require a twice-annual buff and wax for basic maintenance.

5. Does your Uncle Roy brag about putting 5 coats of wax on his car? Tell him he just wasted a lot of wax. When it comes to car wax, more isn’t better; it’s just more. Regardless of whether you wax your car in one pass or 5, daily wear will take that wax off uniformly, in one layer, leaving your car no more protected despite your multiple applications and elbow grease.

6. Caveat Emptor is the rule when shopping for a professional detailer, Hargrove says. Some of their impressive-sounding services are either unnecessary or can actually harm to your car.

For example, steam cleaning an engine–which involves spraying a degreaser on the engine and using a high-pressure water spray to remove it–can get water into electrical parts, or otherwise cause the car to run poorly, Hargrove says. And besides, it’s really not necessary that your car sparkle underneath the hood (though it can be a nice effect if you’re trying to sell the car).

Hargrove also pooh-poohs sealants, which some detailers claim will prolong the life of the paint’s finish. "In my opinion, it’s hype," Hargrove says. "A sealant will give you a shine, but it’s no better than wax. And it’s easy to apply, but you’re not looking for easy–you’re looking for a durable shine that’s going to last a while."

So what's the difference between AWD, 4WD and Full Time 4WD?

> What is the difference between all wheel drive and
> four wheel drive, which one does the rav4 have, and
> what (mechanically) happens when you lock the
> center differential ?

Short, and not without bias:

4WD refers to part time systems, which run in 2WD on pavement, and on which you only engage the other axle (mostly front axle, but there are exceptions) when extra traction/stability is needed. Most (but not all) of these are heavy off-road vehicles with a split gear T-case (high/low range). Most (but not all) have a separate frame. Most (but not all) have solid axles.

Full Time 4WD [RAV4] are those systems which send torque to all wheels all the time, without user interference or axle-engaging automagic systems to achieve that. *Additional* user interference (center diff lock as the most common [RAV4 5sp manual]) and *additional* automagic systems (viscous LSD on center diff mostly [RAV4 auto]) can be present. No real distinction between road-going vehicles and heavy offroad vehicles; both often have full time 4wd (but again only the latter will have a split gear T-case).

AWD (All Wheel Drive) is the least defined category; often it includes the full time 4wd category, but I tend to define it more strictly as those vehicles that *only* send (a significant amount of) torque to the other axle (mostly rear axles, only a few front axles) *after* slip occurs. This behaviour is in contrast to full time, where all wheels get torque all the time, and at least with a fairly even balanced split (50/50% up to 33/66%, but much more bias than that makes it rather AWD than full-time.

A down side of some of the more agressive visco AWD systems is that they tend to bind in tight corners. VW Syncro's are known for this, yet even the Jeep Grand Cherokee Quadratrac (96+ system) is not free of this binding. Not good on ice. Other systems, like on some of the Ford Explorer models, only know two modes: locked or unlocked. Far from perfect as well.

There are only a few heavy offroad vehicles with this AWD, most are road going vehicles.

From a technical/driving point of view you would prefer full time 4wd, as this is the system that gives you the most predictable onroad handling, (corner) stability at high speeds, in cross winds and when towing a trailer. The shifting AWD systems only act after slip has occurred, and only act as long this slip occurs, and you
might be ages in the ditch already before that happens....8-))

Basic summary:

(part time) 4WD: passive, on demand

Full Time 4WD: active

AWD: reactive, automatic

Note that he term 4x4 has not been addressed; I just saw a recent hair split thread that 4WD is considered more work-horse than the 'fancy' 4x4. Does make some sense, as 4WD was put on the very first basic offroad vehicles, yet 4x4 was used to promote them in a more recreational way of use. Nice subjective hair split indeed....:-))

As to your question what locking the center diff on your RAV4 will do: note that this manual lock only comes on the 5sp manual; the auto version comes with an additional visco LSD instead.

Locking this center diff will mean that both front and rear drive shaft rotate at the same speed, regardless of traction on either axle.

This will prevent you getting stuck with one axle (or even one single wheel) spinning on ice, while the other wheels/axle still have sufficient grip (the wheel with the least traction determines your overall traction, and although all wheels get the same amount of torque, it might not be enough to move forward, either uphill or through mud/snow).



Sadly these terms are not subject to rationality/mechanics, but to market droids, many of whom have no idea what they are talking about (especially at dealer level, when pointing to their own, or worse, competitive brands (I still haven't heard the correct explanation about the Mercedes ML-series for example, and that was at two main dealerships....horrifying crap, even from good mechanics).

However, assuming the manufacturer uses the term, it comes down to 3/4
categories:

AWD:
*can* power all 4 wheels, but mostly only does so when, after, and as-long-as slip occurs. In my terminology these are called 'reactive systems', in contrast to 'active' fulltime. Refers mostly to lighter vehicles, without low range T-case. Hardly found on vehicles that are meant for bush work.

4WD:
mostly refering to parttime 4wd, as the 'old system', but IMNSHO it refers to both parttime and fulltime....pointing at more serious/heavy 4x4's, with mostly a low-range T-case (but, since both fulltime and parttime also comes on lighter cars without T-case (heck, even the WWII jeeps didn't have a low range, only a very low 1st gear), that's not a key element).

Parttime-4WD:
normally 2wd, can be manually shifted into 4wd.

Fulltime-4WD:
always 4wd, powering the wheels all the time (unlike most AWD)


As you can see, the market droids have messed up the technical classification, and there is nothing one can do about it.