Purpose of this guide
This car designer guide will go through the entire car design process, asides from engine design, as this is an topic on its own. Also several mentions will be made as how design choices can lead to good, or poor performance. These are not absolute truths, but may stray for min-maxing in certain scenarios.
Additional context information may be given in cursive and are not required to complete a car build.
This guide still is heavily work in progress
Right, let’s get to it then. As of right now in automation, for a car you have a model and trim. A real world example would be Ford Focus as model, and RS or Vignale as a trim. As such trims within a model are bound to the body and the chassis/panel design choices you made for the model. Also a “facelift” would be a new trim of an existing model, and as such trim and model years may differ in Automation.
Asides from outright cost also the production units (PU) and engineering time (ET) are to be considered. Production units is how hard a car is to produce, 110-120 PU in total (including engine) is approximately the effort required to build a modern VW Golf. Engineering time is how long of a development cycle the car will need for everything to be designed and function properly.
Why do trims exist? Because without engineering a brand new car and building/retooling an entire factory, you can make a model that can be adjusted to be sold to multiple target groups. This especially is common in modern automotive industry as more advanced engineering and tooling caused these costs to skyrocket. These costs have a large influence on the required vehicle markup in order for an automotive company to turn a profit.
Choosing a car body
Nr. 1: First off, select the year the model development will start at at in the upper left. Keep in mind that modern car development takes about 6 years, and in the early days (1950’s) about 1-3 years.
Nr. 2: Filter out what kind of car body you want to use. Often the available bodies can be several types and as such if you go by visual reference you could miss the perfect body for your build.
Nr. 3: Select a body.
(Nr. 4: The model and trim name of your current design, the button can be used to switch between them.)
(Nr. 5: The engine family and trim name, the button can be used to switch between them.)
Designing your chassis
Nr. 1: Panel Material: The fabric of the clothes your car will be cladded in.
Steel: Cheap, and relatively heavy, but by far the cheapest solution, easily the most popular choice until the 80’s-90’s. Only the paint protects these panels from rust. In the campaign vehicles that have low “environmental resistance”, or rust easily, will reduce your brand’s image.
Treated steel: Still pretty cheap, but more difficult to produce and engineer. The most popular choice for modern day cars for the masses. Now there’s another, more durable, coating protecting the panels from rust, a pretty solid improvement.
Corrosion Rest. Steel: Better known as stainless steel, expensive kind of steel, also a slight bit lighter because the panels can be thinner due to increased strength. As fast to make and easy to engineer as basic steel, won’t rust, but can put a big dent in your wallet for a budget build.
Fibre Glass: The carbon fibre before carbon fibre, atleast the material itself is cheap, but it takes ages of manual labour to get a shape out of it, and if you crash it, it shatters. Fibre glass is the second lightest panel material in the game though, and it does not rust. It mostly is used in early exotic sportscars, a real world example is the Corvette.
Aluminium: 3rd lightest panel material, still hard to get into shape, but it does not shatter on impact (safer than fibre glass) and is reasonable to repair. It also is perceived as fancier. It is just another type of material so just as easy to engineer. more commonly used in more modern high end sportscars.
Partial Alu: A mixture of untreated steel and aluminium panels. For when you want to save weight, with a limited compromise. Requires tooling for both materials, but is easy enough to produce. Gets more and more common nowadays.
Carbon Fibre: For when you want to save weight and be fancy at any cost.
Nr. 2: Chassis Type: the kind of spine the car has. As usual cost, production units and engineering time are things to consider. Your chassis type may also influence the car’s weight, rigidity, safety, offroad and utility. Rigidity is something that very slightly improves tameness, sportiness and comfort, as a chassis that flexes is both undesired for handling and comfort (panels creaking as the car distorts).
Ladder: As the name says, all major components are assembled onto a big horizontal metal ladder. Very easy to make and assemble parts on. It is far from the lightest or most rigid way to build a car, but as it is oversized at sections for what it needs to be it is durable and it also is good for offroad (ironically due to low longitudinal torsion rigidity). It also is the least safest type of chassis to crash with.
Monocoque: With true monocoques your panels are part of the chassis, kind of like an insect the body is the spine. However for what it is used in Automation the more correct term would be “unibody”. With an unibody the panels still are separate, but everything is assembled onto one big body structure that already takes well after the shape of a car. This is the most rigid, lightest and safest option, but is hard to build (stamping plates into the right shape and then welding a lot of them together), engineer (the structural calculations are more complex and difficult to deal with before the modern day FEM simulations) and can’t just be built in any workshop (huge panels need stamping).
Space frame: Tubes, tubes everywhere forming triangles. Takes more after the shape of a car than a ladder chassis and is both lighter and more rigid, far less ideal than a monocoque or unibody though. It can be built in a shed with some welding equipment, tubes and a grinder. But, it takes both ages to build and engineer (every junction has to be calculated and welded, proper PTSD stuff for the workers and engineers). Pretty good choice if you want to make a limited production car in the early days.
Semi Space frame: The child between the unibody and space frame. The cabin is unibody while the front and rear compartments of the vehicle consist of space frame beams. Usually is a large mixture of both forged and cast parts increasing tooling cost, and not as light/rigid as a full monocoque, but relatively easy to construct. (For a real world counterpart, look up Audi space frame)
Light Truck Monocoque: The child between the unibody and ladder frame. uses unibody for the vehicle except for the cargo area. This theoretically allows for better offroad and towing capabilities due to the ladder frame tail, and reduces the engineering work. It does however not bring the full advantages of a full “monocoque”/unibody.
Nr. 3: Chassis Material: The material your actual chassis is mostly made of.
Steel: Cheap, and relatively heavy, but by far the cheapest solution, easily the most popular choice until the 80’s-90’s. Only paint or nothing at all protects this chassis from rust. In the campaign vehicles that have low “environmental resistance”, or rust easily, will reduce your brand’s image.
Galvanized Steel: Steel treated with a zinc layer, the stuff boat hulls are made of. It’s pretty ingenious as when the zinc layer is interrupted by a scratch a chemical reaction will self repair it to a certain extent. A large interruption in the layer may still result into rust, and as such is not as foolproof as stainless steel. A popular choice for modern vehicles on a budget.
Corrosion Rest. Steel: Better known as stainless steel, expensive kind of steel, also a slight bit lighter because the sections can be thinner due to increased strength. As fast to make and easy to engineer as basic steel, won’t rust, but can put a big dent in your wallet for a budget build. Also, as it is stronger, it is harder to get into shape, and as such tooling costs are increased.