In this guide you will learn the basics for tuning as well as some tips and tricks to get your car ready for the track or street. Keep in mind: tuning mainly means to make the car fit your driving style as best as possible. My recommendation may not fit your driving style and results may vary.

Feel free to request setups, explanations or anything in the comments.

Radiator is the main component to ensure the cooling of your engine. A bigger radiator leads to better cooling. Your engine heats up when driving in high-revs or at the limit of the engine.

• Large size radiator:
  A larger radiator helps to cool down the motor when driving in high RPM for a longer period of time. This means, if you accelerate and drive at high speeds a lot, you might want to consider installing a larger radiator. Large radiators are used when trying to reach the highest top speed of a car. They're also useful for drifting, to help not overheating when cornering in quick succession.
  
  
• Basic radiator:
  Sometimes you might find that a basic radiator is sufficient. You will learn after some experimentation if you need a larger radiator or not.
  
  
• Why would you not install a large size radiator anyway? It adds 3kg of weight to your car. It doesn't sound much at first, but considering sometimes every millisecond counts, every kg does as well.

Additional information: Truck-engines should generally not be driven in the red-zone. They overheat very quick and you get the best performance when the revs are in the green-zone. Your autopilot may overheat your engine if you have the driving mode set to sport or drift.

• Short intake
  A short intake makes the engine respond quicker to the throttle. You will gain more torque in higher revs. This is the choice for racing and street cars.
  
  
• Long intake
  A long intake will shift the torque to lower RPM's. You will install this in most trucks and semi-trucks.

Engines determine how much actual power your car has, but it will also add a lot of weight. Just a one-level higher engine will affect the handling very noticeably. Engines really need to be picked with thought in mind. The V12 400HP might always lead to the highest top-speed, but you won't always be the fastest on the streets/tracks with it.

• Taxi-Driving:
  You will need a compromise between speed and handling. Both need to be well balanced if you want to successfully deliver urgent-comfort passengers in full satisfaction. Too much acceleration may it make much more difficult after a corner to accelerate without spooking the client. This is up to any car by it's on and really requires experimentation and practice.
  
• Trucking:
  You should choose your engine depending on the weight of your cargo. A stronger engine will drain much more fuel and especially with the huge tanks that trucks have, it can take quite a big cut off your overall trucking-income. Bigger is not always better.
  
• Racing:
  The engine should be selected depending on the track and the car of course. For a small track like Olle-Speedway it rarely makes sense to put a 400HP engine in your car. Some cars also simply handle bad if the engine chosen is too big or powerful. Some of the best laptimes on Ansan-Raceway have been made with 340HP engine. With the racetracks currently in game it's mostly important for cars to handle well and be able to corner fast.

The "stock" turbo, which needs to be installed additionally doesn't need to fill up, but grants extra power almost immediately when accelerating. A stage 1 turbo needs some pressurising before it adds to the power, however, you will gain much more boost than the stock turbo.

Turbo-lag isn't very strong in this game (if you drove Group-B cars, you know what I mean), but still you want the turbo to be active at most of times. To ensure your turbo is ready, hold the clutch and accelerate, then release the clutch.

The choice of your transmission determines how many gears your car has and also the specific gear ratios. As far as I know torque-converter transmissions are more suited for strong and heavy vehicles, such as the Mitage or the Mammoth.

• More gears: slower acceleration, higher top-speed
  
• less gears: faster acceleration, lower top-speed

On smaller race-tracks it can make sense to consider smaller transmissions like 4-gear or 5-gear. If you go through many gears in a short time without a longer straight at some point you probably have to many gears.

The higher the number, the shorter your gear becomes.

• higher ratio: faster acceleration, lower top-speed
  
• lower ratio: slower acceleration, higher top-speed

It's important to setup the ratio according your driving-needs. Generally you should ensure, that you can reach the last gear. It doesn't need to hit the limit, but somewhere close to that will make fuel use of the engine. On track-racing your setup should prioritise a compromise between top-speed and acceleration. During the fastest part of a track you should be close to limit your revs. If the track has many corners, it can be favourable to choose faster acceleration over top-speed and driving part of the track reving at limit. Experiment!

Differentials can be quite hard to understand. I'm not an expert myself, but overall you can say: differentials manipulate power transfer between wheels to avoid wheel spin and to ensure equalling distribution. Depending on FWD, RWD or AWD you'll find either front-(FWD), rear-(RWD) or front-center-rear-(AWD)differentials.

Generally you can say:

• Locked diffs, drifter diff will make the car more stable in a straight line, but will decrease cornering speed
  
• Racing-Street, Racing Diff will improve cornering speed at the cost of straight line stability

Extra tip: For offroad hauls it is almost necessary to install locked diffs to ensure the wheels don't lock on uneven surfaces. If you struggle climbing, check if your diffs are locked.

The suspension determines how the car will handle. There are some general rules, however, it also has a lot to do with the driving style. Suspension is THE way to personalise the vehicle and tune it to your needs.

A general rule of suspension tuning is:
Go as stiff and low as possible, WITHOUT compromising handling.
Suspension can be very stiff and low on even racetracks.
Suspension should be higher and softer on uneven racetracks.

Anti-roll-bars regulate how much the drive-train will tilt/roll. Stiffer ARB will reduce body roll of the car chassis which helps staying in control when taking corners in quick succession. Reduced body roll will decrease the weight-transfer and therefor also the weight-difference between wheels.
A stiff ARB will be counter-intuitive on uneven-terrain / offroading. The tires might not be able to keep contact with the surface anymore, reducing overall grip.

Suspension springs determine how much force is needed to compress the spring. The heavier the vehicle, the stronger the springs. Soft springs will help staying in control when crossing uneven terrain. However, it will also increase body roll and reduce overall speed in corners.
Which also means, that a stiff setting can help in corners, since weight-transfer is reduced and grip increased.
However, setting it too stiff will lead to bad handling and the vehicle may become bouncy.
Suspension springs should always be aligned with suspension-damper.

Suspension-damper and suspension-spring work hand hand. The damper kind of regulate how the springs behave and reduce bounciness. Softer dampers will lead to more reactive springs while harder dampers will reduce the wiggle-room of the springs.

You can see yourself best if you setup soft dampers and very stiff springs. See how the vehicle behaves and turn the setup around. This should help giving a feel of how these two components affect the vehicle.

A lower vehicle will have an easier time in corners, since the center of mass is lower and the lever-force on each wheel is decreased. Overall weight-transfer is reduced.
However, uneven terrain will make the car uncontrollably if the suspension is too low.

Wheel-spacer further help reducing body-roll and distributing forces on the wheels. For taller vehicles it can also help prevent to flip it.

Angle-kits increase the possible turn-in of your wheels. This can be especially useful for very long vehicles to make them easier to manoeuvre in tight spaces. Race-cars don't really benefit from it, because it won't increase the speed you can have in a corner.

Brakes
The heavier the vehicle the higher base-value of the brakes. Which also means that brake-upgrades become much more noticeable the heavier your vehicle is.

In rare cases stronger brakes can also help in racing. For me I found out, that stronger brakes, don't help and decelerating faster but rather lock the wheels. Though AWD vehicles seem to benefit from upgraded brakes generally.

Aeroparts
Aeroparts will help greatly to make the car more stable. More air-drag means more air resistance -> slower acceleration. There might be cases where you want to compromise between downforce and air-drag.

Here you can browse through various setups I've made through my Motortown journey.
Due to the workshop being available now for tuning and decal sharing, I will start putting the ID's of tunes here and explain some of them.