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CARFAX 101

• Introduction
• What Consumers look for when shopping online
• How to use CARFAX and Kelley Blue Book in buying and selling a car
• Resale Value
• Certified Used Cars - Caveat Emptor
• Frequently Asked Questions
• Avoid dealer scams
• Teen Safety Tips

Reference:

• Glossary of terms

Which Wheel Drive is Best for You?

Car buying discussions many times leave buyers asking a multiple-choice question: Which is best … front-wheel drive; rear-wheel drive; four-wheel drive; or all-wheel drive?

In the simplest of terms, the difference between the various "drives" is characterized by which set of wheels — or which tires — receive power directly from the engine ... the front wheels or the rear wheels? But what about four-wheel and all wheel drive - how are they different?

To truly appreciate this engineering marvel, we must first better understand the mechanism that transfers the power from the engine to the wheels — it's called a differential . This is key in any discussion of the drivetrain because it is the differential that allows the wheels to rotate at different rates while turning. You may not realize it, but when you're making a turn, the wheels on the outside of the turn are moving faster than the inside wheels — they have farther to go! So, ultimately, the differential is allowing them to move at a "different" rate of speed. Any "slippage" or "drag" of the tires is automatically eliminated by the differential.

So, what benefits does one drive system have over another? In a very brief and highly simplified summary, we've outlined some key points with regard to this potentially confusing topic.

Rear-wheel drive
Rear-wheel drive engineering sends the power from the engine via the differential to the rear wheels. Years back, both cars and trucks were primarily built with rear-wheel drive. There was an engine up front, a transmission came down the middle and the differential/rear axle assembly was in the back. This usually limited the trunk or passenger floor space. Rear-wheel drive allows the rear tires and suspension to work more efficiently by dividing the workload between the driving wheels in the back and the steering wheels in the front. This creates better cornering and stopping power and a makes for a smoother ride. For these reasons, many of today's performance brands still use this technology.

Bottom line: Rear-wheel drive provides more "performance" driving attributes by "pushing" the vehicle into motion from the rear wheels.

Popular new rear-wheel drive vehicles

Mazda Miata MX-5	Ford Mustang
Inifiniti G35	BMW 3 Series
Lexus LS430	Jaguar XJ

Front-wheel drive
Front-wheel drive engineering sends the power from the engine via the differential to the front wheels. With the national emphasis on fuel economy and the auto industry's need to keep production costs low, most cars (especially models under $35,000) are now being built with front-wheel drive. Because the weight of the engine and differential are placed in the front of the vehicle, the front wheels gain better traction. While rear-wheel drive may cause some "spinning out" in bad weather situation, the benefits of front wheel drive are increased traction and safety for the average driver because the car is being "pulled" through the turn. There's also more interior room available since all the engine and drivetrain equipment is up front.

Bottom line: Front-wheel drive provides better gas mileage and traction by "pulling" the vehicle. It also provides more control for lighter vehicles in bad weather driving situations.

Popular new front-wheel drive vehicles

Honda Accord	Toyota Camry
Volkswagen New Beetle	Chevrolet Impala
Nissan Altima	Honda Odyssey

Four-wheel drive
Four-wheel drive engineering sends the power from the engine to all four wheels at once — only when the driver manually selects it — the rest of the time, these vehicles are typically powered by rear-wheel drive. Four-wheel drive is designed to provide extra traction when driving off-road or in mud and snow and allows you to lock down your wheels and kick in equal power to all four wheels at exactly the same time for maximum traction. This type of system also has what is called a transfer case for lower gearing off-road. Many models have multiple locking differentials for different situations you may find off-road. For street driving, the four-wheel drive can be disengaged, manually reverting the vehicle to rear-wheel drive.

Bottom line: Four-wheel drive is a manually selected "mode" with available lower gearing that is found mainly in large SUVs and pickups. When it is engaged, full power goes to all four wheels at exactly the same rate, creating power for snow, weather or towing challenges. In most cases, these vehicles use rear-wheel drive when driving on the street in normal weather.

Popular new four-wheel drive vehicles

Ford F150 Pickup	Toyota 4Runner
2004 Chevrolet Trailblazer	2004 Jeep Grand Cherokee
2004 Ford Expedition	Chevrolet Silverado Pickup

All-wheel drive
All-wheel drive engineering sends the power from the engine via a "smarter" differential to all wheels — only when it senses that it is necessary — selecting the "best" set of wheels for the current driving situation. So, what's the difference between four-wheel and all-wheel drive? With all-wheel drive, the differential technology is truly smart enough to determine which wheel is slipping and direct power to the opposing set of wheels. This means an all-wheel drive vehicle could potentially be operating as both a two-wheel or four-wheel drive vehicle at any given time, depending entirely on the conditions — pretty smart, huh?

In most all-wheel drive systems, most or all of the power is sent to the front wheels until a sensor detects front-wheel slip. This type of technology is being offered in many new cars, especially crossover SUVs. Because of this improved technology, all-wheel drive vehicles are becoming more desirable — both for performance and safety. The advantage to all-wheel drive is that it distinctly improves traction and handling. However, it can also reduce gas mileage because of the increased friction and weight of the drivetrain.

Bottom line: All-wheel drive engineering works most of the time like a "front-wheel drive" with a smart "back-up" power source sent to the rear wheels when needed. This is not, however true in all cases — in some all-wheel drive vehicles there a constant 60/40 split of power from the front to the back wheels. The outcome is better performance and safety in all weather, but mainly for on-road driving.

Popular new all-wheel drive vehicles

Audi A4 (Quattro)	Volkswagen Passat (4Motion)
2004 Subaru Impreza WRX	Nissan Murano
2004 Lexus RX330	Chrysler Pacifica

As a car buyer, increasing your drivetrain knowledge will help you predict what kind of performance and safety you can expect. Probably the biggest factor to consider is whether or not you're driving in snow, mud or ice during the year, driving your vehicle off-road, or are planning to tow heavy loads. Test driving various types of vehicles will also help you determine which wheel drive will eventually drive you.

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