Make use of every Watt: by charging the battery only when your BMW is braking, coasting or decelerating, Brake Energy Regeneration improves fuel efficiency by up to three percent and ensures that the full power of your engine is available for acceleration.

Today’s vehicles require much more electrical energy than older models, due to the much wider array of electric and electronic on-board comfort and safety systems. This energy is created by the generator (also known as the alternator) which converts the engine’s power output into electricity. In conventional systems, the generator is permanently driven by a belt connected to the engine. BMW’s Brake Energy Regeneration operates differently: the generator is activated only when you take your foot from the accelerator or apply the brake. The kinetic energy that would otherwise go to waste is now used efficiently, converted into electricity by the generator and stored in the battery.

Producing electricity in this highly efficient way delivers an additional advantage: when you apply the accelerator, the generator is deactivated - so the full power of the engine can be directed to the drive wheels. Brake Energy Efficiency thus increases fuel efficiency while simultaneously enhancing driving dynamics. As a safety precaution, the Brake Energy Regeneration system monitors the level of battery charge and will, if necessary, continue to charge the battery even during acceleration to prevent a complete discharging of the battery.

Well there are several reasons:

New Brake fluid is fairly incompressible. So when you squeeze your brake, the force in the piston at the Lever goes to the piston at the calliper with the fewest losses. Over time however, a couple of things happen. One is that air can get into the system, either by absorption directly into the brake fluid or more commonly by absorption of water, which contains air.

Air is much more compressible than Brake Fluid. Think in terms of childhood games with a needle-less syringe filled with water. If you put your finger over the end and squeeze the plunger, it doesn’t move at all, or not so you’d notice. With air in the syringe rather than water you can compress it a fair bit. Same happens when air gets absorbed into your brake fluid. It’s what makes your brakes feel mushy or squishy.

The second thing that happens is that the brake fluid can absorb water. This water very often gets into the system as a result of condensation due to heat, from when the brakes or hoses get hot. Water can have dissolved oxygen in it, which when hot expands into small air-bubbles. Enough of these can also make the fluid more compressible. The water, if left in the system, can cause corrosion of the Cylinder, which is what eventually ruins your seals. When you bleed your brakes and the old fluid is brown, part of that is the corrosion.

Water in the fluid will boil and change state from compressible gas to incompressible fluid during the brake application, the change in volume causing a change in brake force. Old brake fluid can cause a failure that is fast and dramatic. i.e. if they get hot from constant use down a hill, you can have a situation where you will have NO BRAKES. So change the fluid regularly.

Basically, if you ever do anything that results in fluid coming out anywhere except the filler, you need to think about bleeding.

As early as 1914 an interlock device was created to prevent a vehicle from shifting into motion on its own. There have been several different types of interlock variations that many car companies have developed, including a brake transmission interlock, a brake shift interlock, and a starter ignition interlock.

A brake transmission interlock works by applying the brakes automatically if no one is in the driver’s seat. If the safety restraints are not being used the brakes are also automatically applied. A brake shift interlock does not allow the gear shift to move unless the brake is applied. The starter ignition interlock it requires a key and the brake to be applied for a manual vehicle to start. Automatic vehicles must have the gear in ‘park’ or in ‘neutral’ in order for the ignition to be started or for the key to be removed.

All Ford SUVs, with first applications beginning in the 2002 model year, offer an advanced tire pressure monitoring system, and will feature as standard equipment antilock brakes with Electronic Brake Distribution for significantly reduced stopping distances and lowered front bumper beams for better car-to-SUV crash compatibility. The SUVs will also offer advanced occupant protection technology in the form of Ford’s patented Personal Safety System and Safety Canopy rollover protection system as well as AdvanceTracTM electronic stability programming. Each of these advanced safety technologies have been available on Ford Escape, Explorer, Explorer Sport and SportTrac, Expedition and Excursion since 2005.

Tire Pressure Monitoring System
This sensor-based low pressure warning system will alert drivers if a tire becomes under-inflated. It will also warn the driver if the tire is significantly over-inflated. The technology features an active pressure sensor mounted inside each tire with a transmitter that communicates with a receiving module in the vehicle. A lithium battery powers the sensor and transmitter. The receiving module contains the logic to determine if the pressure level transmitted if low, and if so it activates a warning message or light and an audible tone.
This tire pressure monitoring technology differs from tire warning systems that operate with a vehicle’s ABS system to detect variances in wheel spin rates (indicating that one of the tires is under inflated). The advanced sensor technology was chosen for Ford SUVs and trucks because of its ability to operate in four-wheel-drive and all-wheel-drive applications and the demanding off-road environment.

ABS With Electronic Brake Force Distribution
Stopping distance is a key measure of a braking system’s efficiency. Because SUVs generally are heavier than passenger cars, they generally have greater stopping distances. Ford will apply new technology and improved brake system designs to significantly shorten the stopping distances of all Ford SUVs.
The first application of this technology is on the new Explorer. A four-wheel, three-channel antilock braking system (ABS) with electronic brake force distribution (EBD) is standard on 2002 Explorer. The ABS controls the front wheels independently and the rear wheels in tandem during heavy braking - to improve vehicle control. ABS with EBD employs dynamic proportioning to achieve shorter stopping distances. It works by measuring braking force versus traction and allocating brake force to the wheels that have the best grip for stopping even before the ABS system kicks in this helps reduce braking distance. For example, 2002 Explorer’s stopping distance from 60 mph is a class-leading 131 feet, a 20 percent improvement from the 164 feet stopping distance for the previous model Explorer.

Personal Safety System

Ford’s patented Personal Safety System combines dual-stage front air bags that deploy based on crash severity, sensors that detect if front-seat occupants are wearing safety belts, driver’s seat position sensors, safety belt pretensioners and load-limiting retractors. The fully integrated, computer-driven Personal Safety System - which debutted on the 2000 Taurus - includes nearly a dozen technologically advanced components. The system, in short, “thinks” about and responds to different accident conditions by deploying the vehicle’s occupant protection systems to match those conditions.

Safety Canopy
Ford’s new side impact curtain air bag system, available on the 2002 Explorer at launch, is one of the most advanced side-impact protection systems available on any SUV in the world. But that’s only the beginning. The side curtain air bags will be combined with additional rollover sensor technology. This patented Safety Canopy system will provide additional protection in rollover accidents. Although rollovers represent only a small percentage of SUV accidents, they can have fatal consequences, particularly when a passenger is ejected from the vehicle. About half of all SUV fatalities involve a rollover. During these types of accidents, occupants thrown from the vehicle are up to 10 times as likely to be killed or seriously hurt than occupants who remain inside. Safety belts are the single best tool for keeping passengers inside during a rollover, but the new air bags and rollover-sensing technology will supply an additional line of defense.
The electronic rollover sensors measure how fast the vehicle’s lean angle is changing to determine whether the vehicle is headed for a rollover. If a rollover situation is detected by the system, it deploys the side curtain air bags to help protect passengers and help keep them inside until the vehicle comes to a complete stop. The air bags remain inflated up to six seconds - far longer than conventional air bags - to provide additional occupant protection. The location of the air bags and physics of the deployment decreases the risk of injury to out-of-position passengers.

AdvanceTracTM Electronic Stability Technology
AdvanceTracTM - a computer-driven interactive vehicle dynamics system. This advanced technology will enhance stability in extreme driving situations when drivers may have misjudged speed or road conditions.
Developed in conjunction with Ford’s involvement in Formula One racing, the optional AdvanceTracTM system monitors driver inputs, such as steering, throttle and brakes, and the corresponding vehicle responses - yaw, lateral acceleration and wheel speed - to control brake force distribution and vehicle stability. When required, AdvanceTracTTM applies the brakes at one or more wheels to correct excessive yaw. (Yaw is rotation about the vehicle’s vertical axis. A vehicle spinning out in a turn is an example of excessive yaw motion.) If the vehicle’s yaw rate is excessive, brake force on the outside front wheel helps keep the vehicle on the desired path. If the yaw rate is lower than that intended by the driver, brake force is applied to the inside rear wheel.

There are four general types of brake pads for cars and trucks:

Semimetallic: This formula, containing about 30 to 65 percent metal, typically includes chopped steel wool or wire, iron powder, copper or graphite mixed with inorganic fillers, and friction modifiers that bond all the ingredients together. These pads are more durable and have excellent heat transfer, but also wear down rotors faster, can be noisy, and may not perform optimally at low temperatures.

Nonasbestos organic: Sometimes listed as organic or NAO, this type of pad is made from fibers, such as glass, rubber, carbon, and Kevlar, with filler materials and high-temperature resins. These pads are softer and create less noise, but they wear faster and create more dust.

Low-metallic NAO: These are made from an organic formula mixed with small amounts (10 to 30 percent) of copper or steel to help with heat transfer and provide better braking. With the added metal, there is more brake dust and they may be slightly noisier.

Ceramic: These are composed of ceramic fibers, nonferrous filler materials, bonding agents, and possibly small amounts of metal. Lighter in color and more expensive than other brake pads, ceramic pads are cleaner and quieter, and offer excellent braking characteristics without wearing down the rotors.

Most manufacturers like EBC Brakes, offer a range of pads for each application. The standard pad, if certified, should meet the demands of normal driving. Upgraded pads for normal driving will likely be noisier, produce more dust, and possibly respond with a harder pedal feel. But if you tow, carry heavy loads or numerous passengers often, live in hilly or mountainous areas, or have a daily commute down a steep grade, you should consider an upgraded or severe-duty pad.

Boasting new safety technology, more refined styling and an improved suspension, the B9 Tribeca is the first-ever Subaru SUV with available seating for seven passengers. The B9 Tribeca features a 245-hp 6-cylinder Boxer engine and a Symmetrical All-Wheel Drive system as its core technology. Subaru is America’s All-Wheel Drive leader, with Symmetrical All-Wheel Drive standard on every vehicle in its model line.

The Subaru B9 Tribeca earned the highest rating in the U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) New Car Assessment Program (NCAP) crash tests (2006 model tested) with 5-stars in both the frontal and side-impact crash tests for both the driver and passenger seating positions. These results are in addition to the 4-star rating in the NHTSA tests for rollover resistance. (No SUV to date has earned 5-stars in the rollover test.)

For 2007, Subaru has further bolstered B9 Tribeca safety technology, equipping all models with a new Rollover Sensor system that detects a potential vehicle rollover and deploys the standard side curtain airbags. The system also sets the seatbelt pre-tensioners in anticipation of an event. In addition, the new Brake Assist joins the extensive roster of dynamic handling technology, which already includes four-channel ABS brakes, Vehicle Dynamics Control and four-wheel traction control. Brake Assist analyzes the force and stroke velocity on the brake pedal and increases hydraulic boost to provide enhanced emergency braking.

Like all Subaru models, B9 Tribeca delivers a high level of “active safety” owing to the all-weather traction of its standard Symmetrical All-Wheel Drive system and the low center of gravity afforded by the Subaru boxer engine design.

Ford is researching and applying active safety measures in production vehicles and concepts designed with the intention to prevent some accidents from occurring. One of these technologies, Ford’s exclusive Roll Stability Control™, is already on more than one-half million Ford Motor Company SUVs since 2005. Unlike any other system in the world, Ford’s patented Roll Stability Control features roll-rate sensing and stability enhancing capability - offering assistance to the driver in maintaining vehicle control during extreme maneuvers. Ford also announced that the 2006 15-passenger E-Series wagon will feature the technology.

Lane Departure Warning, and Collision Mitigation by Braking are the latest safety technologies.

Ford’s Lane Departure Warning System is a technology in development that could help prevent a driver from unintentionally leaving his lane.

Lane Departure Warning (LDW)
Ford’s Lane Departure Warning is a mechanized vision system designed to recognize lane markings and a vehicle’s lateral position to those markings. It can provide a visual, audible and/or haptic (vibrating) warning to the driver if the vehicle departs from a distinguishable travel lane without activation of the appropriate turn signal. In the concept car, a right lane departure triggers a vibration to the right side of the seat; a left lane departure spurs vibration of the left side of the seat.

In Lane Departure Warning, vehicle position is evaluated by a camera system mounted behind the windshield that measures the lateral distance from the camera’s center line to the left and right lane markings. The system works during the day or at night while headlights are in use. Naturally, the system does not warn the driver if the turn signals are used before changing lanes. The system is still under development for conditions without clear lane markings and overall system reliability.

Ford’s Collision Mitigation by Braking system is a technology in development that could help reduce speed in a frontal collision.

Collision Mitigation by Braking (CMbB)
Ford Motor Company’s Research and Advanced Engineering group, in cooperation with researchers at the Volvo Safety Center, developed Mercury Meta One’s Collision Mitigation by Braking or CMbB system to demonstrate how crash severity can be reduced. The system uses sensors that gauge an impending frontal collision and amplify the driver’s braking and then automatically apply additional brake pressure to further reduce the vehicle’s speed at impact.

Depending on relative speed and other factors, every mile per hour that a vehicle is slowed before impact reduces the energy of a crash.

CMbB applies automatic braking when it determines with certainty that a collision with another vehicle is unavoidable in both high and low speed situations. Importantly, the function assumes the driver has ultimate authority, and it will not interfere with any potential evasive maneuver initiated by the driver.

Ford’s CMbB pre-crash sensors consist of a camera and radar to sense vehicles on the road ahead and an electronic control unit (ECU), which determines whether a collision is imminent based on the position, speed and direction of other vehicles. Using estimates of collision threat and driver intent, the CMbB system provides driver warning and enhanced brake control when needed. Depending on speed and road factors, the braking can automatically reduce vehicle speed by five miles per hour or more before an impact. The radar and camera systems are under development so that the system works reliably in heavy rain, fog and other adverse driving conditions.

A comprehensive array of dynamic handling and braking technologies, the Star Safety System includes Vehicle Stability Control (VSC) and traction control (TRAC), an anti-lock brake system (ABS) with Electronic Brake-force Distribution (EBD) and Brake Assist (BA). The Star Safety System helps the driver maintain control of the vehicle in adverse driving conditions. VSC has been standard on all Toyota SUV’s since the 2004 model year.

Four-channel, four-sensor ABS helps to prevent the wheels from locking during severe braking conditions, while EBD distributes proper brake force between the front and rear wheels according to driving conditions and load. The Brake Assist feature is designed to determine if the driver is attempting emergency braking and, if the driver has not stepped firmly enough on the brake pedal to engage the ABS, the system supplements the applied braking power until pedal pressure is released.

The VSC system helps maintain directional stability during cornering by manipulating engine torque and individual wheel-braking influence when it detects tire slippage. The TRAC feature helps reduce tire slippage during acceleration. Toyota’s 4Runner 4WD models use an additional yaw sensor, a deceleration sensor, and control algorithms to deliver smoother torque on any surface, including low-range and locked center differential conditions.

GM has announced in 2005 that all of GM’s cars and trucks sold at retail would have StabiliTrak standard by the end of 2010. However, StabiliTrak is now standard in many GM vehicles. StabiliTrak is General Motors’ trademark name for their Electronic Stability Control system first introduced in 1997 Cadillac models. This helps in low-traction conditions like ice, snow, gravel, wet pavement, and uneven road surfaces. Electronic stability control systems like StabiliTrak, are proven to help reduce single-vehicle crashes.

Using sensors, StabiliTrak detects the difference between the steering wheel angle and the direction you’re actually turning. It also applies quick, precise force to the appropriate brakes to help the driver control the vehicle’s direction to help keep it on course.

Today, the 2007 Cadillac STS includes standard safety features such as the StabiliTrak system and brakes with brake assist technology. One of the things that could follow StabiliTrak relatively quickly is a technology known as panic brake assist. Everything is in place with the StabiliTrak systems to enable the activation of panic brake assist. GM rolls that out on all StabiliTrak-equipped vehicles in coming years. There are other safety technologies that ESC systems can enable, but when it comes to protection in a crash or near crash, the most effective technology remains the safety belt.

Linearity and rigidity – these are the two most important factors that Mazda considers in developing the Mazda braking systems. With linearity, the brakes respond in direct proportion to the amount of pressure the driver applies to the brake pedals. Rigidity ensures that any pressure applied to the brakes makes its way to the wheels. The result: solid, responsive braking and increased brake power.

The featured braking technology that Mazda is now using is the Four-Wheel, Anti-Lock Braking System (ABS) with Standard Electronic Brake Force Distribution (EBD). This technology starts with the renowned MAZDA6.

Through the use of advanced computer software and driver evaluation clinics, engineers were able to design a brake system that delivered confident stopping under various situations and conditions. Conventional brake computer software only looks at pedal efforts required to slow a car from a certain speed. Mazda engineers went so far as to actually measure the brake time actions of typical drivers in an assortment of situations and speeds.

This information was then analyzed and used to develop algorithms for Mazda’s four-wheel, anti-lock braking system (ABS) with standard electronic brake force distribution (EBD) system, which controls the front wheels independently and the rear wheels in tandem during heavy braking to help improve vehicle control. The ABS with EBD employs dynamic proportioning to achieve shorter stopping distances.

EBD works by measuring braking force versus traction and allocating brake force to wheels that have the best grip for stopping even before the ABS system activates. This advanced system helps reduce the braking distance by using the right level of brake modulation for robust stopping and occupant comfort.

Another braking technology used by Mazda is the Standard 4-Wheel Disc Brakes. Disc brakes have such a clear advantage over drum brakes that all modern automobile use discs on their front brakes. Disc brakes in the rear however; can still often be reserved for Performance models, or performance versions of mainstream models.

4-wheel disc brakes are found on all MAZDA3, MAZDA6, MPV, Miata, RX-8 and Tribute i models. The front discs are always ventilated, and in the RX-8, the rear discs are ventilated as well.

Large style wheels are quite the rage right now, but Mazda recalls that one of the functional reasons for larger wheels is to allow room for larger brake discs. For instance, on the MAZDA3, the base i models have 10.9” ventilated discs up front and 10.4” solid discs in the rear. But on s models with 17” wheels the brake discs increase to 11.8” and 11.0” respectively. The advantage of larger brake discs is simple to comprehend. The greater the radius at which brake pads apply pressure, the greater the braking ability. It is a simple matter of relative leverage.

The Brake Assist Function is also used by Mazda. All ABS models are also equipped with a brake assist function. This system aids braking operation during emergency braking or other times when a high amount of brake power is called upon. Research has shown that many drivers, during emergency braking, may apply brakes quickly but without sufficient force. Or they may apply sufficient force but do not maintain it long enough. In these cases, without brake assist the vehicle is not braking to the full extent of its abilities. The brake assist function reads brake pedal depression speed and force, to determine if emergency braking is occurring. If so, the power brake unit applies maximum force and maintains it until pressure on the pedal is decidedly released. This system, combined with ABS helps ensure that the vehicle reaches its maximum braking ability whenever required. MAZDA3