Rare Car Terms You Need To Know If You're A Car Guy

April 6, 2023

Within the auto industry, there are plenty of terms and jargon that are used, from critical components of an engine to terms regarding regulation. There are conversations that every driver will have to have throughout their lives, with family, friends, or that trusty mechanic, where they will encounter at least a few important concepts. Regardless, some words are better left for the mechanic to worry about, while others should be common knowledge for any car owner. Here's a collection of terms that every car guy should know for casual conversation and talks in the shop.

Caliper Configuration

Caliper configuration is a term used to identify hydraulic pistons engaged in a brake caliper, as well as how the pistons are placed. The small hydraulic pistons are motivated by pressure received from the master cylinder. As a result, friction pads press against the disc, ultimately slowing each wheel and bringing the car to a halt. Caliper configuration is a critical process in vehicle safety and must be assembled with precision. There are various types of calipers; sliding, monoblock, swinging, and more. Commonly, disk brakes are used on most vehicles today and require caliper configuration and calibration to create the proper amount of friction when a unit is stopping.

Now that caliper configuration has been discussed; the next car term will be regarding a critical component of an engine.

Compression Ratio

Compression ratio is a term that is commonly used in an internal combustion engine. This is about the ratio of the volume within an internal combustion engine that is enclosed by a cylinder towards the start of a compression stroke in comparison to a capacity closed in afterward. Generally speaking, if one is to increase the compression ratio, they may consequently increase vehicle power. However, there are limits to how high this ratio may go. As diesel engines have a more significant clearance volume, they are capable of achieving higher efficiency.

After talking about vehicle compression ratios, next on the docket will be a useful car function that improves fuel efficiency.

Deceleration Fuel Cut-Off

Deceleration fuel cut-off, otherwise known as DFCO, is next on the docket and has become a beneficial function of fuel-efficient vehicles. Essentially, a car system that allows the vehicle to automatically reduce fuel supply when a driver is slowing down, merely coasting, or even braking. This practice is beneficial as large amounts of fuel are saved over the long-term and therefore, may reduce lifetime costs for the owner. With deceleration fuel cut-off, consumption only returns when acceleration re-engages. DFCO has been said to increase efficiency by up to two percent depending on driver behavior and specific units.

Coming up next for essential car terms is a primary vehicle system that all drivers should be aware of.


The drivetrain or powertrain is a sort of general term in the automotive industry that is, at times, overlooked. The drivetrain is the cumulative term for the parts a vehicle that function to generate power and delegates that power to various components so the vehicle moves. Parts included are typically the engine, driving wheel, drive shaft, axle shafts, transmission, and other pieces in a driveline. It is not uncommon for the powertrain to refer to the engine and driveline, while the drivetrain represents everything minus the engine, though the terms are often used interchangeably.The drivetrain is ultimately responsible for vehicle torque levels; torque being a twisting or turning force composed by distance vector and force vector. Therefore, as one may see, the drivetrain is a critical component of a vehicle’s performance and it is crucial to keep it maintained in excellent condition.

The drivetrain is an essential part of any moving vehicle. However, this next car part is crucial for safety.

A, B, C and D Pillars

Pillars in the auto industry are representative of the vertical and near supports surrounding the window design. Typically cars possess pillars A, B, and C, while D pillars are commonly reserved for larger vehicles such as SUV’s. A strong pillar component in vehicle design is crucial for complying with car safety tests, especially rollover durability. As far as structural knowledge, pillar locations are essential to know for emergency services, such as the fire department when applying the jaws of life in critical situations. The pillars are labeled from front to back, so the A-pillars are near the windshield, while the C-pillars are behind the rear passenger windows.

Now that you know about car pillars and their role in everyday vehicle structure, next up is a term that is important for wheel control when turning.


Differential function of a vehicle is an important one, but very simple. Differential refers to the car component that delegates engine torque between wheels when a vehicle is turning. Without the differential, the output would be equal during turns and would support accurate handling. Essentially the inside wheel rotates at a slower rate than the outside wheel which compensates for distance traveled per unit. Without this crucial component, wheels would be locked together rather than independently spinning. Located where the driveshaft connects with a pinion gear that operates with a ring gear. The relationship between the ring gear and pinion gear comprise the axle ratio; how much power is applied to the wheels.

Yes, the differential is key to turning and changing lanes effectively, but next up is a turn that supports how some car models signal.


LED is a technical acronym for ‘Light Emitting Diode’; a commonly used light source in newer car models. First entering large-scale car production units in 1993, LED’s were utilized as a tail light alternative source. Benefits of using LED’s for automobiles is that they typically require less power to operate than conventional incandescent bulbs. Therefore, by adding light emitting diode’s to a car, the vehicle's electrical efficiency is vastly increased. However, LED’s struggle with heat and, therefore, are required to pass rigorous inspection and safety tests before being implemented in large-scale production.

Now that you are aware of LED proper name and function following is an engine component that is responsible for critical compression.


The cylinder is a key part of any vehicle, as it is where the internal combustion part of internal combustion engine takes place. It is common for multiple cylinders to be lined together in an engine block and must be constructed precisely for maximum performance. This portion of the engine is where the piston travels through and may be found in the average vehicle in one of three formations; Flat, Inline or V. Different formations make for different advantages, such as performance and overall production prices.

After learning about vehicle cylinders, the next function is a beneficial system to have in your vehicle for safe braking.


Antilock Braking System is next up on the list as an essential system that can be found in a majority of vehicle sold on the market today. Essentially, this system is a computer-generated system that prevents skidding during emergency braking. This function is important for the common driver because it returns control to the vehicle operator. Also, ABS is effective at reducing stopping distances on dry pavement, which is crucial in preventing rear-ended accidents because wheels are not locked during braking. Unfortunately, since the primary role of ABS is meant to keep control of the vehicle, it can reduce braking on loose surfaces. Although useful in many situations, inner city driving is especially improved with more controllable stopping.

ABS is important for slowing down safely, but this next term is responsible for getting more power.


Direct Diesel Injection (DDI) is a beneficial system included in some vehicles that increases performance and saves on fuel economy. DDI is a process where fuel is injected directly into the combustion chamber, increasing power output compared to a standard engine; the location of injection is altered, as opposed to the method. As a result of direct injection, a prechamber is not required for combustion. Another benefit of having a DDI system is that fuel emissions are drastically reduced as less carbon is released in contrast to typical vehicles on the road.

Following is a function that some electric cars use as a means of ensuring they are capable of far destination trips.


E-REV is a term used for alternative electric engines that are designed to ensure more extended range for electric vehicles rather than depending on an entirely electrical system. An internal combustion function is included which powers a low-level charge in the battery when energy levels are sparse. Essentially a petrol-engine assumes control when the electrical charge is entirely used up. However, the combustion engine does not power the wheels, but in fact, only charges the battery. For weary travelers concerned about long drives but still want to drive an electric vehicle, this is a reliable solution.

Now that you are aware of a popular electric car function, next discussed will be a phenomenon that happens to cars frequently.

Aerodynamic Drag

Aerodynamic drag, often just called "drag," is a term that is often heard in sports car design or racing events. In simple terms, when a vehicle is traveling, aerodynamic drag refers to the resistance of the air as the car moves through it. This phenomenon slows down a car via pushing air resistance and is therefore very important to design for in racing such as Formula 1. Bigger, box-shaped vehicles typically have worse aerodynamic drag; a strong reason for the pointed front of many sport and luxury car designs. The type of drag experienced by the average car on the road is called frontal pressure; occurs when the vehicle must push through collective air molecules.

Upcoming are terms that many people should already be aware of, however, accompanied will be a comparison and description of this common concern when purchasing a car.

Automatic / Manual Transmission

Automatic and manual transmissions are two different vehicle systems; both are found in American vehicles although automatic has become more common. Manual transmission allows for a driver to physically shift the transmission into a desired gear via a gear-shift while engaging a clutch pedal, allowing for safe and smooth gear transitions. Automatic transmissions, in contrast, do all the work for the driver by engaging a motor that can automatically switch gear ratios without operator assistance. Looking at both functions, it is simple to see why many new drivers and vehicles prefer automatic vehicles, as they remove much effort and interaction on the road. When choosing a car, it is up to the owner to decide which transmission system they would prefer.

Now that you know the difference between automatic and manual transmission, next up will be a car part that is crucial to ensure cars do not overheat.


A radiator provides a critical function in a vehicle and is responsible for transferring heat away from the engine. This is achieved when hot coolant moves through the radiator grill, where the air is blown over it to cool the liquid. The cool liquid is then pumped back through the engine to absorb excess heat, before returning to the radiator to be cooled again. Typically on either side of a radiator is a tank that possesses a transmission cooler. Currently, a majority of radiators used in common vehicles are aluminum since aluminum is cheap and disperses heat quickly. A car’s radiator is a vital component of the units cooling system which activates when an engines core temperature gets too high. Radiators use either water or coolant to reduce a vehicle's temperature levels caused by friction and fuel burning, just be sure to swap the water out before winter, lest it freezes and ruptures a line or pump.

Following radiators, last but not least will be a term that is important for all potential owners to consider when purchasing a vehicle.


MPG is an acronym for ‘Miles Per Gallon’ and is a common yet important term for car owners to be conscious of. Specifically, this term is used as a reference to the distance (in miles) that a vehicle may reach when using about a gallon of fuel. Typically, governments attempt to implement minimum requirements for vehicles to achieve to maintain a reasonable importation of fuel as well as ensure community air pollution is kept at a reasonable level. MPG will vary between vehicles and vehicle sizes. It is important to discuss a product’s fuel efficiency before purchase to ensure that the car will make a suitable fit for the owners. Becoming more common around the world and viewed as a more accurate measure of fuel economy is Liters per hundred kilometers.