A structure which provides the roof support on a vehicle, located on the rear most part of larger vehicle such as an SUV, a minivan, or a wagon.

Dealer Cash Incentives

Cash payouts provided to auto dealers from manufacturers with the primary goal of improving or stimulating vehicle sales. These payouts provide a high incentive for dealers to lower their prices, making the lower price point a much more attractive selling feature for prospective buyers. Incentives are either paid outright to stimulate sales or earned by a dealer’s purchase of a vehicle from the manufacturer. Additional incentives may be provided upon the sale of a vehicle or if a dealership meets a specific sales quota within the agreement. These agreements are laid out between manufacturers and dealers with specific terms and conditions for each incentive.

Dealer Holdback

A percentage of a vehicle’s sale price which is repaid back to the dealership by the manufacturer after the vehicle has been sold. This can be either the MSRP or invoice price depending on the manufacturer’s specific terms. The repayment is employed to help incentivize the sale of vehicles to meet quotas and move inventory at a more rapid pace.

Death Brake

A series of devices on a vehicle that automatically apply the brake when certain conditions are detected. In most cases, an automatic system will apply the brake if it does not detect a heartbeat from the driver.

Deceleration Fuel Cut-Off

A system which shuts off the fuel supply to the engine while an automobile is either coasting without accelerating or in the process of braking. By cutting off the fuel, this can help to improve overall fuel efficiency while enhancing the engine braking effectiveness. Once the vehicle needs to accelerate again, fuel is resupplied to the engine. The system engages and disengages seamlessly as needed without a disruption to the driver.

Deceleration System

An emissions device equipped on manual transmission vehicles which help to reduce the overall amount of exhaust being released into the environment. While the automobile is shifted into gear and the throttle is closed, this device bleeds vacuum from the intake itself. This process closes the fuel injectors as a vehicle is decelerating and not actively engaging them. As a result, this closing off of the system prevents unnecessary emissions from escaping from the vehicle.

Declaration Page

Otherwise known as the “Declaration of Insurance,” this is the section of an insurance policy which provides all the pertinent information about a policyholder. Details include the name and address of the insured, the policy period effective and expiration dates, the exact property which is insured (whether it is a vehicle, home, or other item), the premiums, and any additional or supplemental information relating to the policy. These are highly important documents as they give clear, straightforward records of specific insurance information.


Also known as freewheeling, the process of disengaging the transmission of a vehicle from its driveshaft when its RPM goes above the transmission’s RPM. This type of declutching can be done either manually or through some automatic device or system equipped in the vehicle.


May refers either to a test drive with a prospective vehicle or a vehicle itself which was showcased as a demonstration model at a dealership to highlight all its available features.


The total cash amount by which a vehicle loses in its value over time and use. This figure is determined by a large number of factors including overall mileage, age of the vehicle, locations where it was operated, and any damage or accident reports. In the development of vehicle leasing agreements, projected vehicle depreciation is used to determine a residual value and a monthly lease payment amount. The factors involved in determining this number may vary based on a vehicle, a dealership’s policies, and other factors.

Descent Control

Operational control system similar to a cruise control system which is built for off-road usage. The system utilizes both an ABS and traction control system to continuously modify and manipulate all four brakes across a vehicle’s wheels. This type of independent control of each brake allows the vehicle to better move along steep, uneven terrain without losing traction, slipping, or experiencing other problems. When driving slowly (at walking speed), these systems are much more effective than if a driver operated brakes normally which would activate all four simultaneously. For drivers frequently on rough, off-road terrain, this type of system provides an ideal way to maintain safety and full control of a vehicle at all times.

Destination Charge

The total amount which a manufacturer charges for freight costs to ship and deliver a vehicle from the production facility to the dealership. This number is not part of the MSRP; it is an additional charge which is incurred within the vehicle price. In most cases, the dealer includes this as part of their pricing, effectively passing this charge on to the consumer. While shipping distances vary, the destination fee remains the same amount for specific vehicles no matter where they are being shipped to in the continental United States. However, additional costs are sometimes incurred for transporting these vehicles to Alaska or Hawaii. The rates are specific to vehicles and determined by the manufacturer. In some cases, dealers can waive this charge as an additional consumer incentive to lower a vehicle’s purchase price.

Diesel Engine

An automobile equipped with an engine which utilizes diesel fuel as well as a compression ignition. These engines are frequently available in larger trucks, SUVs, and 18-wheelers.

Diesel Engine Hour Meter

A display which provides the total amount of time, measured in hours, that a diesel engine has run throughout its entire lifetime. This meter can be either digital or analog and installed somewhere on the primary display dash. It provides an additional component to a vehicle’s usage beyond the mileage.

Diesel Exhaust Fluid

Also known as DEF, a fluid which is injected into a diesel engine’s exhaust as it moves from the engine to the catalytic converter. It helps to break down emissions into their base ingredients of nitrogen and water for a cleaner exhaust.

Differential Fluid

Fluid which aids in the lubrication of all the gears inside a differential to facilitate smooth and comfortable wheel rotation.

Direct Injection System

A type of fuel injection system where the nozzles are present within each piston’s combustion chamber within an engine. The injection nozzles provide fuel directly within these chambers for immediate combustion effects.

Direct Shift Gearbox

Also known as a “DSG,” “Sequential Manual Gearbox,” “SMG,” or “Automated Manual Transmission.” Refer to “Automated Manual Transmission” for more information.

Disc Brake Type

The type of disc brake rotors equipped in a braking system. The types include slotted, vented, solid, ceramic, carbon, and cross-drilled. Specific vehicles are equipped with specific brake types depending on their precise requirements.

Disc Changer

A system equipped within a CD or DVD player which provides space to store multiple discs and switch them when desired. When equipped in a vehicle, this provides a convenient way to store and quickly switch to different CDs within the internal audio system.


Measured in cubic centimeters (CCs), calculated from the total volume of air that is displaced within a vehicle’s engine cylinder while the piston is in the bottom center multiplied by the total cylinders which are in a vehicle’s engine. In general, the displacement measurement can give a rough estimate as to an engine’s overall size and potential power.

Disposition Fee

The total amount of money charged by a leasing company to pay for the cost of retrieving and reselling a leased vehicle. This fee is incurred at the end of a lease only when the lessee does not opt to purchase the vehicle they were leasing. In most cases, this charge is presented to the lease holder after the leasing period is complete and the vehicle has already been retrieved or returned.While this fee is fairly common for vehicle leases, it may not be a component of the agreement if it was negotiated out of the terms between the lessee and the leasing company.

Distributor Cap

A nonconductive cap placed on the distributor. The cap includes the primary contacts which lead to each of the spark plugs. The total number of contacts will vary based on the number of spark plugs within a specific vehicle.

Distributor Rotor

The component of a distributor which completes the electrical circuit between a spark plug and the ignition coil to provide power within the system. This rotating mechanism is nonconductive to prevent inadvertent discharge of electricity anywhere else within the system. Specific contacts must align to complete the circuit and provide electricity from the spark plug.

Diverter Valve

A specific valve used to dilute the air fuel combination within an engine system to help reduce overall emissions from the vehicle during operations. These valves are present within engines that include an air pump. During operation, the valve works to divert air from the pump directly into the intake itself. This process combines air with the fuel, lowering the total amount of fuel exhaust that would have otherwise been discharged within a vehicle’s emissions.

DMV Fees

Costs and expenses associated with the Department of Motor Vehicles. Often referred to as “title and license fees,” these costs cover the specific elements related to a vehicle’s administrative and registration information within a state. Specific fees and amounts will vary based on whichever state a vehicle is being registered or purchased in. These fees may include other expenses such as renewals, license plate ordering, and more.

Down Payment

Payment made in cash which is applied against the total purchase price of a vehicle. This amount reduces the total amount of money owed which will reduce the loan amount required to finance a vehicle. Within a leasing contract, this term is frequently referred to as a vehicle’s “Capital Reduction.” Specific dealerships and cars may require a minimum down payment to buy or lease. However, these factors are determined specifically during the negotiation process between a buyer and a dealership.

Downshift Cable

Within a transmission, a cable which is responsible for accommodating the transmission shift downward into a lower gear. This cable is connected directly to the throttle and is primarily used for rapid gear shifting when an accelerator is quickly depressed down beyond a specific threshold. It can help to move a transmission to the proper gear at a faster pace when the driver requires it.

Drain Plug Washer

A sealing washer which is used on a bolt-style drain plug within a vehicle. This washer can be made from several different materials which are typically either plastic or a composite.

Drive Axle Boots

Accordion-like covers which are used to cover and protect a vehicle’s constant-velocity joints located on the drive axle shafts. Boots are highly flexible and have a conical shape. They also contain a high amount of lubricant for both joint protection and effective and smooth operation.

Drive Belt Tensioner

Device which helps to maintain the proper tension on a drive belt. This device is self-adjusting, and it will change as necessary to maintain a consistent tension level.

Drive Belt

Belt which accommodates and transfers the engine rotation starting from the crankshaft pulley toward all the various devices responsible for enabling a vehicle’s operation. This includes rotation transference for devices such as the water pump, air conditioner compressor, power steering pump, and the alternator. Depending on the specific vehicle, more than one drive belt may be present within the system to enable all these functions.

Drive Shaft

A metal tube which connects an engine to a vehicle’s differential on four-wheel drive or rear-wheel drive models. The tube is typically constructed from a durable, sturdy metal material and includes universal joints on both of its ends. This connection is essential for proper operation of these types of wheel rotations in four-wheel and rear-wheel automobiles.

Drive System

The mechanisms and components which determine how wheels are controlled within a vehicle. These control two-wheel drive, four-wheel drive, and all-wheel drive.

Drive Train Mounts

Mounts which are attached an automobile’s drive train to various elements of its chassis. Mounts are constructed from durable, flexible material and provide a built-in method to help absorb some of the energy within a drive train operation. They help to add more stability to the overall engine operation. They may be connected to the chassis from the differential housing, transfer case, or even the transmission itself.

Drive-Off Fees

The total overall cost which must be paid to a lessee to secure a vehicle lease and drive the car off the lot. These costs are paid directly at the start of a vehicle’s leasing period. In most cases, they include a variety of fees and charges related to both the vehicle and the leasing company. Typical examples of these expenses include a security deposit, first month’s payment, documentation fees from the dealership, registration and other state-based fees, and acquisition fees. Specific amounts will vary depending on the leasing agreement determined during the negotiation process. In many cases, some of these fees can be waived due to dealer or manufacturer incentives. May also be referred to as “Total Due at Signing.”

Driver State Sensor

System equipped within a vehicle utilizing eye detection technology to assess a driver’s eye motion and other vital signs during operation. These sensors can provide an added level of safety by applying the brake or sounding an alerting when specific indicators are not detected.


System within a vehicle’s wheels which is responsible for connecting the transmission to the drive axles, generating and providing power to them and allowing for driver control during vehicle operation. Several components all work together for overall drivetrain functionality.

Drivetrain Warranty

Refer to “Powertrain Warranty” for more information.

Driving Lights

Secondary high-beam driving lamps used to amplify visibility even more under specific operational circumstances.


Also referred to as “Direct Shift Gearbox,” “Sequential Manual Gearbox,” “SMG,” or “Automated Manual Transmission.”Refer to “Automated Manual Transmission” for more information.

Dual Mode Hybrid

A hybrid automobile that includes two distinctly different driving modes. Each one of these modes provides a specific system by which a vehicle can operate, and they both work in flux to provide seamless operation of a vehicle while in use. In most cases, the first mode is a fully electric mode which draws power solely and directly from a vehicle’s battery system. Current technological and battery limitations typically restricts this type of all-electric operation to low-power driving conditions for slower driving or lighter acceleration circumstances. The second mode is a more traditional gasoline engine which will activate whenever the power or acceleration demands exceed what the electric mode can effectively handle. Gasoline mode can activate either when harder driving or acceleration is needed or when the electric system runs too low on power. As the gasoline mode is used, it also recharges the electrical system for later use.

Dusk-Sensing Headlights

A headlight feature which is used to automatically turn lights on under specific lighting conditions. When this system is activated, both headlights and taillights are automatically turned on when the amount of detected ambient light decreases at dusk.

Dynamic Brake Control

Refer to “Emergency Brake Assist” for more information.