D
Dealer cash incentives
Amounts that are paid to dealers by manufacturers to stimulate vehicle sales by incentivizing the dealers to lower their prices to consumers, typically paid or earned upon the dealer's purchase of the vehicle from the manufacturer, upon the dealer's sale of the vehicle, or when the dealer achieve specified sales volume targets.

Dealer holdback
A percentage of either the MSRP or invoice price of a new vehicle (depending on the manufacturer) that is repaid to the dealer by the manufacturer after the vehicle is sold. For more information, see www.edmunds.com/advice/incentives/holdback/index.html.

Death brake
A system of devices, including a heart rate sensor, that applies braking when the driver's heart stops beating.

Deceleration system
An emissions device on a manually shifted vehicle that bleeds vacuum from the intake when the vehicle is in gear with the throttle closed. This causes the fuel injectors to close during conditions of deceleration and results in reduced emissions.

Declaration page
Also referred to as the "Declaration of insurance." The portion of a property or liability insurance policy that states the name and address of policyholder, the property insured, its location and description, the policy period, the premiums and supplemental information.

Declutching/freewheeling
The act of disengaging a vehicle's transmission from its driveshaft, either manually or automatically, when its driveshaft's rpm exceeds the transmission's rpm.

Demo
(i) a test drive; (ii) a vehicle that has been used as a demonstration model by a dealership.

Depreciation
The amount by which a vehicle (or any physical item) loses its value over time. In vehicle lease transactions, the projected depreciation of the vehicle is used to determine the vehicle's projected residual value and the monthly lease payments.

Destination charge
The fee that the manufacturer charges to deliver a vehicle from the factory to the dealership, and that is passed on by the dealer to the consumer; it is not included in the MSRP of the vehicle. The destination fee is the same for a particular vehicle no matter where the dealership is located (with the exception of Alaska and Hawaii in some instances).
 
Diesel engine
A vehicle with an engine that uses diesel fuel and compression ignition.

Diesel engine hour meter
A digital or analog display that shows the amount of time (in total hours) that a diesel vehicle's engine has run over its lifetime.

Differential fluid
The liquid used for lubricating gears inside the differential.

Direct injection system
A fuel injection system in which the injection nozzles are located inside the combustion chamber of each piston.

Direct shift gearbox
Also referred to as "DSG," "SMG," "sequential manual gearbox" and "automated manual transmission." See "Automated Manual Transmission."

Disc brake type
The type of brake rotors: solid, vented, slotted, cross-drilled, ceramic or carbon.

Disc changer
An in-dash or remote-mounted CD or DVD/CD player that can store and read multiple discs and play them through the vehicle's audio system.

Displacement (CC's)
The volume, in cubic centimeters, of a vehicle's engine cylinder with its piston at bottom dead center, multiplied by the total number of cylinders in the vehicle's engine.

Disposition fee
An amount charged by the leasing company at the end of a lease that is intended to cover the cost of retrieving and selling the vehicle if the lessee chooses not to buy it. The lessee is billed for this charge after the vehicle is returned.

Distributor cap
The nonconductive cap of the distributor that contains the contacts leading to each individual spark plug.
 
Distributor rotor
The rotating, nonconductive component of a distributor that contains contacts and that, when aligned, complete an electrical circuit between the ignition coil and a spark plug.

Diverter valve
On an engine equipped with an air pump, a valve activated during deceleration that allows air from the air pump into the intake to dilute the air/fuel mixture (in an attempt to reduce emissions).

DMV fees
Department of Motor Vehicle fees. Sometimes referred to as "title and license fees." The fees payable to the state in which a vehicle is purchased and/or registered, primarily for vehicle titling, registration and license plates.

Down payment
A cash payment credited against the purchase price of a vehicle, which reduces the amount to be financed. In a lease transaction, this amount is often referred to as the "capital reduction."

Downshift cable
A transmission cable connected to the throttle that shifts the transmission into a lower gear when the accelerator is depressed suddenly beyond a certain point.

Drain plug washer
A composition or plastic sealing washer used on a bolt-type drain plug.

Drive axle boots
The flexible, conical, accordion-like covers that contain lubricant and protect the constant-velocity joints on a drive axle shaft.
 
Drive belt tensioner
A self-adjusting device used for maintaining proper tension on the drive belt.

Drive belt(s)
A belt that transfers the rotation of the engine through the crankshaft pulley to drive various devices, such as the alternator, water pump, air conditioning compressor or power steering pump.

Drive shaft
A sturdy metal tube with universal joints on either end that connects the engine to a differential on a rear-wheel or four-wheel drive vehicle.

Drive system
The type of drive system: two-wheel drive, four-wheel drive or all-wheel drive

Drive train mounts
Flexible, energy-absorbing components that attach parts of a vehicle's drive train (for example, the transmission, transfer case or differential housing) to the chassis.

Drive-off fees
Also referred to as "Total Due at Signing." The total cost that must be paid by the lessee at the inception of a vehicle lease, which typically includes the first month's lease payment, any security deposit required by the leasing company, any acquisition fee charged by the leasing company, any documentation fees charged by the dealer, and various state registration fees.

Driver state sensor
A device that monitors a driver's eye movement and/or vital signs while a vehicle is in motion.

Drivetrain
The system of components that generates power and transmits it to a vehicle's wheels.

Drivetrain warranty
See "Powertrain warranty."

Driving lights
Auxiliary high-beam driving lamps.

DSG
Direct shift gearbox. Also referred to as "SMG," "sequential manual gearbox" and "automated manual transmission." See "Automated Manual Transmission."

Dual-mode hybrid
A hybrid vehicle with two different drive systems, referred to as Modes. In the first mode the vehicles runs solely on an electric motor powered by the vehicle's battery system. When the electric-only mode is low on power, or during harder acceleration and faster speeds, a gasoline engine mode will initiate. The second Mode uses a gasoline engine to help power the vehicle and recharge the electrical system batteries.

Dynamic brake control
See "Emergency brake assist."