Trim Design

Introduction

In Automation, once you have created a car model, and selected an engine, you are ready to start building the individual variants of the car models. This is where you configure the car's aesthetics, drivetrain, wheels, brakes, suspension and interior. You can also export your car to BeamNg.drive, a driving simulation game. To help with explaining the Trim Designer, I will use an example compact car from 2020 with 3 available configurations: a cheap basic sedan, a sports sedan, and a fuel efficient hatchback. I have named the car the "Sprinter", and the 3 variants are the "GE" (cheap), "GTS" (sports) and "HX" (eco).

Choosing Body Styles

In most chassis selection, you are able to choose a body style. This means your model can be available as a sedan and hatchback, or truck and SUV. Not all chassis have such selection, here are common combinations listed:

Combination 1

• Sedan
• Wagon
• Coupe
• Hatchback (3-door and 5-door)
• Convertible (including cabriolets)
• Ute (pickup truck based on a car)
• Fastback (in between hatch and coupe)

Combination 2

• 2-door Truck
• 4-door Truck (known as crew cab)
• SUV (2-door and 4-door)
• Van

The small button on the upper left corner of the screenshot above is to disable body morphing. Body morphing is a method where you can push and pull certain parts of the car body to your aesthetic tastes, to refine the look you want to achieve.

Paint

In this tab, you can paint your car using 5 default materials (paint (default paint is light red metallic), carbon fiber, plastic, chrome, bare steel) or you can create your own custom paint. The 5 default materials are recommended to only be used for trim rather than painting the entire car. You can also create your own custom paint, by hitting the large plus button and using the color mixer, reflectivness, metallic grain, and pearlescence sliders.

In the paint slots tab, you can choose which part of the car receives paint/material. The yellow section includes the entire car, primary body area, secondary body area (if available), bumpers (if available) and hood. The blue section involves trim pieces, such as decorative trim (available on some car bodies), window trim, door pillar trim, mirror color (most car bodies now have removed their mirrors, mirrors are now placed separately as fixtures) and additional trim slot (if available). The green section involves wheel paint. This includes the entire wheel, the primary wheel slot, the secondary wheel slot (if available) and the wheel edge. The final button is to paint brake calipers on cars with disc brakes. All these choices are purely aesthetic and do not affect any car mechanics, although you can try to achieve a convincing look for the type of demographic you are attempting to sell the car to.

Fixtures

This tab is where the car really takes shape and ends up looking like a car. Here is where you install everything that makes a car look like a car. Everything except downforce fixtures are purely cosmetic.

All fixtures are categorized to help in finding them (as there are plenty of fixtures now, with more to come in future updates). The fixtures are all made to fit a broad time range. Some fixtures will list what year they're made to fit best.

• Lights
  • On the yellow tab, you will find lights. The top button is for bookmarked light fixtures. The second button is for headlight types. These lights shine onto the road ahead in various different means. The older style lights are meant to represent sealed beam headlights, a type which was standardized since the 1920's until the 1980's. These types of lights were still used on cheap cars of the 90's and utility vehicles of the 2000's. They are in square, rounded square and circle shapes. More modern lights are either halogen lights, HID lights or LED lights. Some light fixtures have one version with halogen lights and another with HID/LED combination. The third tab is for tail lights. Tail lights are all halogen style. They all are mostly red, with small portions in orange for indicating and white for reversing. Some modern tail lights are known informally as Altezza lights, and are styled with completely clear covers and red and orange bulbs on the inside. The fourth tab is for indicators, they can be mounted anywhere but are usually put on the side. To make a realistic looking car you should make sure both ends of the car have indicators. In the U.S. cars are allowed to use red as an indicator color for the rear. In most cases manufacturers put orange bulbs behind clear cover for aesthetics
• Air intakes
  • In the blue tab, you will find grills, vents and air scoops. In older versions of the game, these used to have function by influencing cooling and drag calculations by measuring their surface area. Now it is aesthetic. Grills and vents come in many shapes to play with, so get creative. Air scoops are mounted on top of the hood, with the same purpose, to take in air.
• Downforce
  • In the green tab are items which affect your car's aerodynamics. Lips are mounted on the bottom of your bumpers, spoilers are mounted at the tip (the decklid) of the trunk or hatch, and wings are like spoilers except they are raised even higher by supports. When you place these fixtures, they give you more options down the road to influence downforce and drag.
• Additional Car parts
  • The red tab includes fuel filler caps, door handles and mirrors. Try to keep the style period correct if you want. Fuel caps are usually mounted in the rear quarter panel, door handles are on doors obviously and mirrors are either mounted on the front doors themselves or on the front fenders. Fender mounted mirrors were popular from the 60's to the 80's, sadly they've fallen out of style.
  • The grey tab includes antennas, license plates, bumpers and trim, badges and lettering.
• Miscellaneous
  • The teal tab includes wheel designs, exhaust tips, and a miscellaneous tab which includes additional badges, decals, and mudflaps

The fixture designer allows you to morph, position, rotate, and change the layering and positioning method of the fixture. You can also undo or redo these changes, flip the fixture, mirror it, delete or lock it.

When a fixture is selected (for example this headlight) you have the option to change the materials used in them. Some materials are only available when the fixture is in default state, they cannot be reselected. Material availability depends on which part of the fixture is being edited. Selectable materials include car paint, hood paint, secondary car paint, trim paint, plastic, rubber, carbon fiber, chrome. Materials for light cover include transparent plastic, red, white and orange reflector, light, and translucent plastic. There are also different types of chromes. With grills and vents, the mesh pattern can be modified.

Here is the example car, available in 3 trims, 2 body styles. All have distinct styling, yet they are part of the same car model range. The left car is the cheap budget version, the middle is the sports version, the right is the economy hatchback.

Drivetrain

The drivetrain is what connects the engine to the wheels. Drivetrain choices depend on engine mounting and suspension set up. In this tab you also configure the transmission, differential type, and power distribution (AWD only)

Drive Type: Which wheels get driven. This selection is influenced by engine position (front, mid, rear) and placing (longitudinal, transverse).

Gearbox: Which type of transmission puts engine power into the drive system.

• Manual: cheapest, simplest, efficient, sporty and hardest to drive. The driver manually operates the clutch and selects the gear. Manuals have the least power loss, and is the transmission type of choice for budget cars and sports cars.
• Automatic: this transmission type dispenses of a clutch and uses a liquid torque converter instead. The transmission is mechanically operated.
• Advanced Automatic: same as automatic, except it is electronically operated by the ECU.
• Sequential: similar to manual, except the clutch is automated and the driver chooses when to shift up or down. This transmission has faster shift times than automatic but much more complicated. It is used by rally cars, and by super cars.
• Dual Clutch (DCT): a development of Sequential, with two clutches instead of one. This transmission shifts very fast, and is the choice of modern super and hyper cars.

Ratios: the amount of gears in the transmission. More gears means better potential acceleration or fuel economy.

Top Speed: this setting affects the final drive of the transmission. The lower the top speed, the more aggressive the final drive, which leads to higher acceleration. A top speed calculation is made of your car, and you adjust gearing accordingly. Longer gearing improves top speed (to a limit) and fuel economy. Many cars use their top gear as an overdrive gear, an excessively long gear made to run the engine at lower RPM while the car is at higher cruising speed, thus greatly benefiting fuel economy. The +/- option is only available on fuel injected cars. This option limits the car electronically at any desired speed by cutting fuel when the car hits the designated limit. This allows the car to use cheaper tires rated for lower maximum speeds, at the expense of prestige.

Spacing: affects at what RPM each gear after first starts at. A higher spacing means the engine will start at lower RPM after up shifting. It's best to optimize it based on the power curve of the engine and purpose of the vehicle.

Differential: a mechanical device that splits power in an axle. FWD and RWD cars have one differential between the driven wheels, 4x4 has two differentials between the front and rear wheels, and AWD has three differentials, one between the front wheels, another between the rear wheels, and a third in between both axles.

• Open: power is divided and sent off to the wheels. This is the simplest differential that only transfers power. This differential allows wheels to spin at different speeds. It doesn't lock the axle when needed, which can cause one wheel peels in rough driving situations. This means one wheel has lost grip and is just spinning freely.
• Locker: differential made for off road vehicles. Lockers are made to remain simple, while effectively locking the wheels, ensuring they spin at the same speed. This is great for low traction situations. However these make steering much harder, as wheels need to spin at different speeds when the car corners. They also increase tire wear. They can be manually or automatically engaged
• LSD: Limited slip differential. This differential locks the wheels when one loses grip, ensuring they spin at the same speed. This makes it far easier to drive normally. This differential is commonly used in sports cars. Geared, Viscous and Electric refers to how they are engaged. Viscous, the cheapest LSD uses a fluid similar to transmission fluid in automatics to spin the wheels at the same speed. Geared uses spider gears to do the same. Electric is powered by the ECU which manages power distribution, and engages the differential when needed.

Power Distribution: AWD only. Affects how much power is sent to the front and rear wheels, which in turn affect driving dynamics (sportiness, drivability)

Wheels and Tires

The wheels of a car are compared to man's feet, and the tires are the shoen. Wheel and tire configuration is important, as it affects grip levels for performance, rolling resistance (which reduces fuel economy), off road and utility capabilities.

Tire Type: used to choose how the tires are constructed.

• Cross Ply: older tire technology developed in 1898, these tires are cheap and tough. However they can't handle higher speeds, create too much rolling resistance leading to poor fuel economy, and are limited in size and profile
• Radial: developed in 1946, these tires are now universal. They are virtually better than cross ply in every single measure except for cost.

Tire Choice: affects rubber compound used in tire construction

• Offroad: is shaped to maximize grip in mud or dirt, at the expense of road grip. Is the cheapest and hardest rubber compound
• Hard long life: most cars use hard long lasting rubber compound. Best fuel economy due to low rolling resistance.
• Medium compound: is a softened form of hard long life. This compound has better grip andAllo high comfort. The softer a rubber compound is, the wider the tire needs to be to have the same load capacity.
• Sports compound: a version of medium compound but with reduced tread for added grip.
• Semi Slicks: a compound made for maximum road legal grip on the track. Has minimal tread to increase grip at the cost of environmental resistance.

Tire Width: width of tires. Wider tires are more expensive, but provide more grip. Thinner tires reduce rolling resistance, promoting fuel economy. Maximum width is determined by wheel well size (which can be changed by morphing the body around the wheels) and minimum width determined by compound and car's weight.

Parameters: additional wheel settings

• Tire diameter: more diameter is good for off road. Less diameter makes the wheel lighter. This, alongside Rim diameter, affects tire profile. More profile is more comfortable, less is sportier.
• Rim diameter: larger rims are more favorable for performance. Rim sizes depend on tire diameter.
• Offset: how far the wheel sits from the axle. More offset reduces grip.

Rim Material: what the rim is built out of. Lighter wheel is always better for sports cars

• Steel: standard steel alloy. Is the toughest and cheapest wheel, suitable for off road and most road cars
• Alloy: aluminium alloy. Lighter, and still somewhat cheap, suitable for modern road cars and sporty cars.
• Magnesium: even lighter, this material is used in older performance cars.
• Carbon fiber: lightest, most fragile and most expensive. Used in super and hyper cars.

Brakes

Cars need to stop. That's what brakes are for. They transfer the rotational energy of the wheel into friction and dissipates it as heat. Brakes have a limit to how much heat they can handle, when they surpass the limit, fade happens. The brakes lose power until they can be cooled off again. Bigger brakes are more resistant to fade. Brake size also affects their strength. Upsizing brakes is more effective than increase caliper piston count, caliper piston count should only be increased if the large brake isn't enough.

Brakes: Choice of brake type and material.

• SLS Drum: A single shoe drum brake. The brake's "shoes" house the brake pads and are situated inside the drum. When the brake pedal is pushed down, the shoe push out on the drum.
• 2LS Drum: 2-shoes drum brake. Stronger than SLS, only available on the front axle.
• Solid Disc: When the brake pedal is pushed down, a caliper press down in a pinching motion on the disc. A caliper with more pistons has more stopping power.
• Vented Disc: A disc with grooves, slots and holes drilled into it. This increases ventilation and the disc's surface area, allowing it to cool faster and fade less.
• Carbon Ceramic Disc: A disc made out of carbon ceramic composite material. This material is very effective at dissipating heat, and is used to line space shuttles to shield them from heat as they re-enter Earth from outer space. These brakes are very expensive and are only used on high performance super/hyper cars.

Size: Size of the brake drum/disc. Maximum size is limited by rim size. Bigger brakes fade less and are more powerful.

Pad Type: Composition of brake pad material. Affects braking power, brake fade, and comfort. Normal cars use a 30 type pad (mentioned by game developed KillRob in his GE:TD video series)

Brake Bias: Affects the distribution of brake power. Optimum brake balance is dependent on how powerful the front and rear brakes are, as well as the front and rear wheel grip.

Aerodynamics

Aerodynamics can be used to improve grip, engine and brake cooling, fuel economy and top speed.

Undertray: a shield placed under the car that affects how air passes under the car.

• Skidtray: The skidtray has minimal effect on aero. Its purpose is to shield the engine sump from rocks and debris, and is usually used in offroad and rally cars.
• Semi/Fully Clad: additional metal plating used to cover axles, exhaust, and other items under the car that can cause drag. Allows the car to be more aerodynamic.
• Downforce: Cladding designed to promote downforce by using air passing under the car. The amount of downforce is configured using the Downforce slider, more downforce increases grip at the cost of top speed and fuel efficiency

Active Aero: Various flaps that can be activated electronically when needed. Active wings will adjust their geometry based on current speed, to optimize downforce or reduce drag when needed. Cooling flaps are flaps that actuate when the engine needs additional cooling, otherwise they remain closed, reducing drag.

Wing Angle: Affects the amount of drag and downforce. A higher angle makes more downforce, more downforce means more drag. These options are disabled if no aero fixture is installed on the car.

Cooling Airflow: Affects the amount of cooling air that reaches the engine. 50 is optimum for the engine, higher than 50 increases engine reliability at the cost of drag, lower does the opposite.

Brake Airflow: Affects the cooling of brakes. More airflow creates more drag but reduces brake fade.

Interior

The interior of the car has large effect on desirability, comfort, and weight.

Seats: Seat count. The amount of rows depend on the car body, coupes get one or two rows, sedans and hatchbacks get two rows, wagons, minivans and SUVs get three rows.

• Captain's Chair: The captain's chair is counted as one full seat, two can be placed next to each other. This type of seat is used for both front passengers in virtually all cars, and both rear passengers for luxury cars. These are the most comfortable seats
• Bench seat: The bench seat is counted as three full seats. It is commonly used as the rear row for 2-row cars or the middle row of 3-row cars. They are still rather comfortable.
• Jump seats: Jump seats are small seats that can be stowed away, they either come as individual seats or as an entire bench. They aren't considered full seats, so they are counted as +2 or +3 seating. These are used in the 3rd row of SUV's and minivans. These seats can be stowed away for additional cargo room.

Interior: The inside of the car. The options come as packages that include materials, speaker system, sound deadening, and ergonomics.

• Basic: designed for budget cars and fleet utility vehicles. Interior is made of cheap plastics, rubber, and seats are vinyl.
• Standard: designed for the mass market. Interior is made of higher quality plastics, carpeting, and seats are cloth.
• Premium: designed for comfort. Interior is made of high quality materials, well carpeted, and seats are leather.
• Sport: designed to be light yet still comfortable. Sound deadening is mostly ignored, interior is made of light plastics or carbon fiber, bucket seats are used.
• Luxury: designed for even more comfort: Interior is made of natural materials, thick carpeting, and higher quality leather seats.
• Hand Made: designed for prestigious luxury cars. Interior is hand stitched with high quality materials, fully optimized for comfort.

Entertainment: Devices used as additional features for the car interior. Availability of device types depend on the years. Types include: Phonographs, AM Radios, 8-track systems, Cassette systems, CD systems, SatNav, Infotainment, and HUD (Heads Up Displays)

Safety and Driver Assistance

These devices are used to enhance car safety while on the road or in case of an accident. They also enhance car control.

Power Steering: Eases control of the car by boosting steering control through hydraulic or electric means

• None: No power steering. The driver has his strength to turn the wheel. Light cars can get away with using this option. This option provides the driver with the most road feedback, and is most reliable.
• Hydraulic: Hydraulic power steering boosts the driver's steering strength through hydraulic pumps. The driver still gets some road feedback, because the wheel still has physical connection with the steering system. Variable systems allow the driver to configure the strength of power steering boosting at the expense of reliability.
• Electric: Drive-by-wire system, no physical connection between the driver and steering system. No road feedback. The driver's steering input is processed by an on board computer.

Traction Aids: Assist the driver in controlling the vehicle through various digital means.

• None: No assistance.
• ABS: Anti lock braking system. Prevents brakes from locking the wheels. Without ABS, the driver would have to brake in a way that compensates for wheel lock to maintain front wheel grip for steering. ABS has been required in Europe since 2004. ABS has never been made mandatory in the USA, but in 2013 Traction Control with ABS has been made required.
• TC+ABS: Traction control with ABS. Traction control is a computer system which controls the power that goes into the drive wheels. When the wheels start losing grip, it reduces power to prevent wheel spin.
• ESC: Electronic Stability Control. A more advanced form of TC which also is made to further reduce wheel spin.
• ESC+LC: ESC with Launch Control. Launch control holds the car's engine at a desired launch RPM. This is used in sports cars for optimum acceleration.

Safety: Protects the car's passengers through various technologies such as airbags and crumple zones. Availability of options depend on the year of manufacture

Suspension

While the actual suspension type was already configured in the model selector, in this tab you select the spring type, damper type, sway bar type and tune it all.

Springs: the primary device that cushions the car from the wheels and road surface. Their object is to keep the car body as smooth and comfortable as possible while keeping the wheels as firmly planted on the surface as possible.

• Standard: Typical passive suspension springs
• Progressive: Springs that have tapered ends. This spring type is good at absorbing small bumps as if they weren't there. It negatively affects handling due to its inconsistent feel.
• Hydropneumatic: Bags filled with fluid in the place of springs. These are very good for keeping the car "afloat" as if there is a 100% smooth surface. These springs are only good for comfort/luxury applications
• Air: Bags filled with compressed air. Less specialized than Hydropneumatic springs.
• Active: Electronically actuated springs and dampers. Can prioritize comfort uses or sport uses. These offer overall best performance, however you can only use Twin-Tube dampers with them.

Dampers: stops the springs from continuously bouncing the car after hitting a bump

• Twin Tube: Uses two pistons to control spring movement
• Gas Mono-tube: Uses a single gas filled piston to control spring movement.
• Adaptive: Can have their hardness set automatically by road condition and spring settings
• Semi-Active: Dampers that can be set up for different purposes by the driver

Sway Bars: stops the car from rocking left to right after hitting a bump

• Passive: stops sway
• Semi-Active: activates when needed
• Offroad: sway bars designed to keep the car stable in steep grades
• Active: can be set up for different driving environments

Presets: Loads a pre-selected suspension tune and ride height, based on car weight and suspension equipment. Comfort suspension makes the suspension as soft and floaty as possible. Normal suspension is just an average value for all settings. Sport makes the suspension as tight and low as possible to maximize grip at the expense of comfort. Utility makes the suspension tight and rather high in order to maximize load capacity. Offroad lifts the vehicle and gives it soft suspension to crawl over all sorts of terrain and obstacles.

Tuning

• Camber: Affects the wheel's angle in relation to the surface. A camber of 0 means the wheel makes a 90 degree angle with the wheel. Positive camber is useless. Decreasing camber below 0 (negative camber) makes the car sit slightly lower and increases grip up to about -5.0 degrees. This comes at the cost of uneven tire wear. Normal cars have cambering between 0 and -1, sports cars go between -1 and -3.5, super cars use -3.5 to -5. Wheels attached to solid axles cannot be cambered.
• Springs: Spring stiffness. Stiffer springs increase low capacity and grip at the cost of comfort.
• Dampers: Damper stiffness. Stiffer dampers control the car's behavior better at the cost of comfort.
• Sway Bars: The strength and amount of sway bars. A higher value reduces sway, at the cost of comfort and additional weight.

Ride Height: How high the car rides over the ground. Is slightly affected by wheel diameter and camber. Lower height is better for sportiness, higher height is better for load capacity and off road. If you go too low, the car will bottom out causing damage. If you go too high, the car will be unstable due to high center of gravity.

Testing

Congratulations, your car is fully built up. Here is how it stacks up against the competition!

Design mode will read out car and engine statistics. Markets mode shows how your car performs in various demographic sections of the car market. This can be influenced by selecting profit margin and country where the car is being sold. Detail Stats provides an in depth readout of all your choices, how they affect vehicle dynamics, and how they affect demographic desire. The test track runs your car on a fictional New Zealand race track. You can also run the track yourself in BeamNG.drive after exporting your car.

Summary

The summary will read out the same screen as the design mode in the Testing tab. It will also give you the option to export the car to BeamNG.drive, by pressing on the BeamNG logo below the Export tab.

Have fun!