SpecDB¶

The SpecDB is the name of the database that Polyphony Digital uses to store all car specifications, and other critical entities such as courses. Its structure is the same as an ordinary database.

Most tables represent a distinct car part. Some other tables such as COURSE defines the courses available in the games.

Important Information¶

Car codes are the car's row ID in GENERIC_CAR.
label is what the game uses to identify a car.
category column is the part's upgrade level.

Torque Modifiers¶

torquemodifiers determine how much a part increase the torque output of a car in %. 100/1000 is 100%, no changes.

For each table that the game reads the multiplier is applied to the car's value as such CurrentTorqueMultiplier = (CurrentTorqueMultiplier * TableTorqueMultiplier) / 100

Table row load order for setting up a car (for GT4, crossed tables do not have a torque modifier)

~~BRAKE~~
~~BRAKECONTROLLER~~
~~STEER~~
~~CHASSIS~~
ENGINE
~~DRIVETRAIN~~
~~GEAR~~
~~SUSPENSION~~
~~LSD~~
~~FRONTTIRE~~ + (TIRECOMPOUND, TIRESIZE & TIREFORCEVOL)
~~REARTIRE~~ + (TIRECOMPOUND, TIRESIZE & TIREFORCEVOL)
~~LIGHTWEIGHT~~
~~RACINGMODIFY~~
PORTPOLISH
ENGINEBALANCE
DISPLACEMENT
COMPUTER
NATUNE
TURBINEKIT
~~FLYWHEEL~~
~~CLUTCH~~
~~PROPERLLERSHAFT~~
MUFFLER
INTERCOOLER
SUPERCHARGER
~~ASCC~~
~~TCSC~~
~~BALLAST~~
~~WING~~
~~NOS~~
~~VARIATION~~

Database Tables¶

The most important tables are GENERIC_CAR and DEFAULT_PARTS.

Mandatory table rows for a car (click to expand)

GENERIC_CAR
DEFAULT_PARTS
BRAKE
BRAKECONTROLLER
STEER
CHASSIS
ENGINE
DRIVETRAIN
GEAR
SUSPENSION
LSD
FRONT/REARTIRE (+ TIRESIZE, TIRECOMPOUND, TIREFORCEVOL)
RACINGMODIFY (GT4)
TURBINEKIT
ASCC
TCSC
VARIATION
MODEL_INFO (GT6)
CAR_NAME If you want a name
CAR_CUSTOM_INFO (GT6).

Table Name	Description
`AIR_CLEANER`	Defines all Air Filter tuning parts.
`ARCADEINFO_NORMAL`	Defines all possible AI arcade entries.
`ASCC`	Defines all ASM parts.
`BOOST_CONTROLLER`	Defines all boost controller parts. (for >=GT5)
`BRAKE`	Defines all brake tuning parts.
`BRAKECONTROLLER`	Defines all brake controller parts.
`CAR_CUSTOM_INFO`	Unknown.
`CAR_NAME_*`	Defines all names for cars for each region. The row ID is and should be linked to the ID in `GENERIC_CAR`.
`CAR_VARIATION_*`	Mainly used for GT4, this defines all car label/model mappings for each region.
`CATALYST`	Defines all catalyst tuning parts.
`CHASSIS`	Defines chassis specifications such as dimensions, mass, and weight bias.
`CLUTCH`	Defines all clutch parts.
`COMPUTER`	Defines all ECU tuning parts.
`COURSE`	Defines all courses in the game. In GT5, `courselist.xml`, the arcade and freerun xmls refer to it using their labels. In GT6, menudb refers to it for available arcade courses.
`COURSE_NAME_*`	Defines the course names for `COURSE`. (for GT4)
`DEFAULT_PARAM`	Defines all the default part settings for each car.
`DEFAULT_PARTS`	This is the second most important table. Defines all the pre-installed parts for a car. Each column will point to a part table's row ID.
`DISPLACEMENT`	TODO
`DRIVETRAIN`	Defines all drivetrain parameters.
`ENEMY_CARS`	Defines all enemy/AI cars, this can be used in place of GENERIC_CAR for defining cars. (a GENERIC_CAR row is still needed to use this. for GT4 only).
`ENGINE`	Defines all engine display/simulation specfications and assigns sound IDs to engines for `carsound` entries.
`ENGINEBALANCE`	Defines all engine balance parts. (for GT4)
`EXHAUST_MANIFOLD`	Defines all exhaust manifold parts.
`FLYWHEEL`	Defines all flywheel parts.
`FRONTTIRE`	Defines all front tire parts.
`GEAR`	Defines all transmission parts such as number of gears, gear ratios, and whether or not a given transmission has customisable/auto ratios.
`GENERIC_CAR`	This is the most important table of the SpecDB. This is where cars are defined as a whole along with their metadata. The default parts column is used to link a car to its default parts installed using the Row ID. You may also find the horn sound ID, price of the car, country, maker (manufacturer) and some car specific flags.
`GENERIC_ITEMS`	Mainly used for GT5, this defines all the available items in the game, which then the gameitem xmls will use. Note: GT5 has a hardcoded limit of 280 horns.
`INDEP_THROTTLE`	TODO
`INTAKE_MANIFOLD`	Defines all intake manifold parts.
`INTERCOOLER`	Defines all intercooler parts.
`LIGHTWEIGHT`	Defines all lightweight parts.
`LSD`	Defines all differential parts.
`MODEL_INFO`	Defines all the available models for each car. Row ID's are directly linked to the car's row in `GENERIC_CAR`. (for >=GT5)
`MUFFLER`	Defines all exhaust upgrade parts. Categories are used to determine which subfolder is searched in `carsound`.
`NATUNE`	Defines all naturally aspirated tuning parts.
`NOS`	Defines all nitrous parts.
`PORTPOLISH`	Defines all port polishing parts. (for GT4)
`PROPELLERSHAFT`	Defines all propeller shaft parts.
`RACE`	Defines all races in GT4. Label must match a certain pattern.
`RACINGMODIFY`	Defines racing modifications (GT5) or aero/chassis data (GT3/GT4).
`REARTIRE`	Defines all rear tires.
`STEER`	Defines steering assist parameters.
`SUSPENSION`	Defines all suspension parts.
`TCSC`	Defines traction control parts.
`TIRECOMPOUND`	Defines tire compounds. Used by FRONTTIRE and REARTIRE.
`TIREFORCEVOL`	Defines tire force volumes.
`TIRESIZE`	Defines tire sizes. Used by FRONTTIRE and REARTIRE.
`TUNER_LIST`	Defines which tuner/dealer you can go to to upgrade a car in GT4.
`TURBINEKIT`	Defines all the turbos.
`VARIATION`	Defines all the car paint colors (and models, for GT4).
`WHEEL`	Defines all the wheels.
`WING`	Defines all the wings. (for GT4, maybe GT5P)

CAR_VARIATION¶

Applicable to: GT4 / TT

Links a car to a VARIATION row.

Table (click to expand)

Column	Data Type	Description
`Label`	String	The human-readable reference name for the car. Must match with the car to search.
`VariationID`	Int	ID matching VARIATION.

CHASSIS¶

Applicable to: GT4 and above

CHASSIS defines all the car dimensions, weight, grip and rigidity stats.

Table (click to expand)

Column	Data Type	Description
`Label`	String	The human-readable reference name for the part. Matching this to the GENERIC_CAR label isn't mandatory, but keeps things simple.
`length`	Byte	The car's length in mm. Seems to have no effect on car handling, with wheelbase taking precedence.
`height`	Byte	The car's height in mm. Seems to have no effect on car handling.
`wheelbase`	Byte	The distance between the front and rear wheels. A shorter wheelbase will cause exaggerated forward-and-back weight transfer while accelerating and braking, while a longer wheelbase will provide better stability at the cost of worse braking distances and traction due to the car's weight being more centralised.
`mass`	Byte	The car's weight in kg.
`dlength`	Byte	The car's display length in mm, visible in the spec sheet in-game.
`dheight`	Byte	The car's display height in mm, visible in the spec sheet in-game.
`dmass`	Byte	The car's display weight in kg, visible in the spec sheet in-game (before the car is purchased).
`performanceF`	Byte	A grip modifier for the front wheels. A higher performanceF results in improved turning ability, better corner exit traction in FWD's, and reduced tyre wear. A high performanceF (and a low performanceR) will induce oversteer.
`performanceR`	Byte	A grip modifier for the rear wheels. A higher performanceR results in improved mid-corner grip, better corner exit traction in RWD's, and reduced tyre wear. A high performanceR (and a low performanceF) will induce understeer.
`treadF`	Byte	Unknown, seems to have no effect on car handling.
`treadR`	Byte	Unknown, seems to have no effect on car handling.
`width`	Byte	The car's width in mm. Seems to have no effect on car handling.
`dwidth`	Byte	The car's display width in mm, visible in the spec sheet in-game.
`category`	Byte	Unused, all cars have it set to 0.
`cartype`	Byte	Unknown, possibly unused (1 seems to denominate non-production cars, but also includes many production Skyline GT-R's, Lancer Evo's and other newer models).
`percentageF`	Byte	Defines the car's weight distribution, specifically the percentage of the car's weight that rests on the front wheels. A percentageF of 50 means that the car has a balanced 50:50 weight distribution. Weight distribution affects the car's overall handling, traction and tyre wear for both front and rear, depending on whether the car is more front-heavy or rear-heavy.
`yaw`	Byte	Appears to be a body roll/turning ability modifier that scales based on the car's mass. A low yaw means that the car can turn more fluidly and is more responsive to turn inputs. Yaw is unaffected by placing a ballast on the car.
`cheight`	Byte	The distance between the ground and the floor of the chassis.
`WheelLayout`	Byte	Defines how many wheels the car has (0 = four wheels, 2 = three wheels).
`GrowInch`	Byte	Unknown.
`TireWidthR`	Byte	Unknown.
`FrontStiffness`	Byte	A turning resistance modifier for the front of the car, with higher values resulting in more resistance while turning.
`RearStiffness`	Byte	A turning resistance modifier for the rear of the car, with higher values resulting in more resistance while turning.
`GasCapacity`	Byte	Would define the car's gas capacity, but seems to be unused, all cars have it set to 100 (except cars which can't be used in races with pitting enabled).

ENGINE¶

Applicable to: GT4 and above

ENGINE defines all the car engines/parts.

Table (click to expand)

Column	Data Type	Description
`Label`	String	The human-readable reference name for the part. Matching this to the GENERIC_CAR label isn't mandatory, but keeps things simple.
`Displacement`	String	The engine's displacement capacity. Formatted as cubic capacity (e.g. `4965cc`) for piston-driven engines, and (cc * rotors) (e.g. `654x2cc`) for rotor-driven engines. Blank/hidden values are `- cc`.
`EngineType`	String	The engine's layout, used for dealership stat displays (e.g. `L4` for inline 4, `Boxer6` for flat 6, `Rotor2` for 2-rotor, `V6`, `V10`, etc. and `-` for blank/hidden).
`Cam`	String	The camshaft/valve type if applicable. Overhead cams and valves are listed as their abbreviation, e.g. `DOHC` or `OHV`. `Rotary` is listed in full, and blank/hidden is `-`.
`Aspiration`	String	The aspiration type of the engine, used for dealership stat displays and possibly event restrictions. `NA`, `TURBO` (and `TUBRO` for the Lancer Evolution III), `SuperCharger`, and `-` are used. Twincharged cars are not supported, so cars such as the Lancia Delta S4 are listed as turbo.
`psrpm`	String	Display stat. The RPM at which peak power is achieved.
`torquerpm`	String	Display stat. The RPM at which peak torque is achieved. As this is a string value, ranges such as `2500-6000` are supported where required (e.g. turbo cars)
`soundNum`	UShort	The ID for this engine's sound, mapped to files like `carsound\xxxx\12345`, where xxxx is the folder for normal or turbo engines split by exhaust upgrade level.
`psvalue`	Short	Display stat. The engine's peak mechanical horsepower (PS). Converted to other units in-game depending on region/language settings. Combines with `psrpm` to produce readouts such as `Power:301HP/5600rpm`.
`torquevalue`	Short	Display stat. The engine's peak torque (kgm*100). Converted to other units in-game depending on region/language settings. Combines with `torquerpm` to produce readouts such as `Torque:339.22ft.lb/2700-4250rpm`.
`torque(A through X)`	Short	Simulation stat. Each lettered column is mapped to a `rpm(A through X)` column to produce this amount of torque (kgm^100) at a given RPM, building the torque curve of the engine (e.g. `torqueE` is the torque produced at `rpmE`).
`Category`	Byte	Unknown.
`dpsflag`	Byte	Unknown. Possibly related to downshift protection.
`shiftlimit`	Byte	The RPM at which the automatic transmission assist will shift up under full throttle. Values for this and all other RPM-related sim values are multiplied by 100 in game, so a `shiftlimit` of `65` means the redline starts at 6500rpm.
`revlimit`	Byte	The RPM at which the engine hits the rev limiter and will not rev any further. Also multiplied by 100 in game, so `70` means the rev limiter is hit at 7000rpm.
`Unk`	Byte	Unknown. Possibly RPM related.
`clutchmeetrpm`	Byte	Not fully known. Seems to be `250` for almost every car except for some historic cars and the Tank Car.
`torquepoint`	Byte	How many `rpm/torque` points are used to build the torque curve. Maximum of 24 as each only goes from A to X.
`rpm(A through X)`	Byte	RPM values divided by 100 corresponding to `torque(A through X)` values. Can start from any value and jump up in any (or even inconsistent) intervals, but base game cars typically start at 10 or 15 (1000rpm and 1500rpm) and increase in intervals of 5 (500rpm).
`RedLine`	Byte	The RPM at which UI redline starts.
`MeterScale`	Byte	Unknown. All values are set to `0` in GT4.
`torquevol`	Byte	Unknown. Possibly a multiplier related to the engine's torque curve.
`GasConsumptionRate`	Byte	Unknown. As the name suggests this is related to fuel consumption, but every engine in GT4 has a value of `0` for this column, and the units/effects are unknown. Possibly unused.

GEAR¶

Applicable to: GT4 and above

GEAR defines all the car transmission mechanisms/parts.

Table (click to expand)

Column	Data Type	Description
`Label`	String	The human-readable reference name for the part. Matching this to the GENERIC_CAR label isn't mandatory, but keeps things simple.
`Gear(1st through 11th)`	Short	The gear ratio for a given gear. Multiplied by 100, so a specdb value of `3595` is a ratio of `3.595`.
`GearReverse`	Short	The reverse gear ratio. Multiplied by 100.
`finalgearMIN`	Short	The minimum value allowed for the final drive ratio when tuning gear ratios.
`finalgearMAX`	Short	The maximum value allowed for the final drive ratio when tuning gear ratios.
`finalgearDF`	Short	The default value for the final drive ratio when tuning gear ratios.
`ExtraFinalGearRatio`	Short	Specifies an alternative final drive ratio where applicable (for cars with two output shafts such as the 2005 Volkswagen Golf GTI).
`Price`	Short	How much the part costs to buy if not stock.
`category`	Byte	The upgrade level of a transmission part.
`geartype`	Byte	Which type of gearbox behaviour to use. Refer to Gear Type Enum
`Nshift`	Byte	Number of gears (forward). This also reflects how the driver shifting animations operate.
`gearflag`	Byte	Determines whether or not to calculate the gear ratios automatically. `0` is used for road cars with specified real-world ratios, `1` is used for most race cars and upgraded gearboxes. `2` is unknown and only used on the 1954 Chevrolet Corvette which has two gears and real-world defined ratios. `AutoGearRatio_Generate` is called if the flag is not `0`.
`maxspeedMIN`	Byte	The minimum value allowed for the `Auto` adjustment slider when tuning gear ratios.
`maxspeedMAX`	Byte	The maximum value allowed for the `Auto` adjustment slider when tuning gear ratios.
`maxspeedDF`	Byte	The default value for the `Auto` adjustment slider when tuning gear ratios.
`ExtraFinalGearUsage`	Byte	Subtracted from `Nshift` to determine which gear the `ExtraFinalGearRatio` is used for. For example, `ExtraFinalGearUsage` set to `2` and `Nshift` set to `6` means that the ratio specified in `ExtraFinalGearRatio` will apply from 4th gear onwards.
`LowGearPos`	Byte	Used for rendering the driver animations. Likely related to shift animations, as it appears to only be set to `1` for convertibles with a manual gearbox and `0` for everything else.
`ReverseGearPos`	Byte	Used for rendering the driver animations. Similar assignments to `LowGearPos`, but has a larger range of possible values (`0`, `6`, `8`, and `255`).
`GearPattern`	Byte	Used for rendering the driver animations. Refer to Gear Pattern Enum

Gear Type Enumeration¶

Gear Type

Note

Information based on GT7. Not all may be available in previous games.

Value	Name
`0`	`GEAR_TYPE_CLASSIC`
`1`	`GEAR_TYPE_LINEAR_CVT`
`2`	`GEAR_TYPE_SPORTS_CVT`
`3`	`GEAR_TYPE_TOYOTA_HYBRID`
`4`	`GEAR_TYPE_RIGID`
`5`	`GEAR_TYPE_TQ_CONV_AT`
`6`	`GEAR_TYPE_DSG`
`7`	`GEAR_TYPE_SCOOTER`
`8`	`GEAR_TYPE_TC_SST`
`9`	`GEAR_TYPE_F1_SEAMLESS`
`10`	`GEAR_TYPE_KART_1AT`
`11`	`GEAR_TYPE_NON_SYNCHRO`
`12`	`GEAR_TYPE_TQ_CONV_AT_QK`
`13`	`GEAR_TYPE_AMT`
`14`	`GEAR_TYPE_NON_SYNCHRO_MT`

Gear Pattern Enumeration¶

Gear Pattern

Note

Information based on GT7. Not all may be available in previous games.

Value	Name
`0`	`DRIVER_GEAR_PATTERN_NO_USE`
`1`	`DRIVER_GEAR_PATTERN_H`
`2`	`DRIVER_GEAR_PATTERN_SEQUENTIAL`
`3`	`DRIVER_GEAR_PATTERN_BUTTERFLY`
`4`	`DRIVER_GEAR_PATTERN_AUTOMATIC`

GENERIC_CAR¶

Applicable to: GT4 and above

GT4 Table (click to expand)

Column	Data Type	Description
`Label`	String	The internal name for a car. Used throughout the game engine and Adhoc scripts to refer to a specific car.
`DefaultParts`	Int	The row index for a car's DEFAULT_PARTS entry. Essentially used to actually build a car by assigning it to a bundle of parts.
`Price`	Int	How much a car costs to buy. A value of 0 doesn't mark the car as free, but rather flags it as unbuyable. Also used for internal calculations of sell price and mileage-based price reduction for cars available in the UCD.
`Year`	Short	The year a car was built. Used for event regulations.
`RegulationDisplacementFlags`	Short	Used for event regulations, values/units unknown.
`Maker`	Byte	The manufacturer of a car. Used for manufacturer-specific event regulations.
`Category`	Byte	Assigns cars to a certain "type". `0` = `NORMAL`, `1` = `RACING`, `2` = `TUNING`, `3` = `CONCEPT`. Equal or above to `100` is a car that is considered "strange" (e.g. Formula GT, Ford Model T, Nike One) - They have no body/engine/oil degradation and cannot be used in certain parts of the game (`You cannot advance past this point because <car> is a special car.`)
`GeneralFlags`	Byte	Bit-level flags assigning certain characteristics to cars, used in bitwise operations.
`ConceptCarType`	Byte	Unknown. `Category` is used for concept car event restrictions, and `ConceptCarType` has some strange assignments, such as the Ford Model T being set to `4`. Appears to be completely unused/unread.
`OpenModel`	Byte	The convertible type of a car. Cars set to `1` have a closed top variant that allows them to enter regular 6-car races. Cars set to `2` do not, and can only enter 2-car races or time trials.
`NoChangeWheel`	Bool	Restricts the ability to buy wheels in GT Auto.
`NoChangeWing`	Bool	Restricts the ability to change wings in GT Auto.
`SuperchargerOriginally`	Bool	Whether or not this car has a supercharger as standard. Likely used in tandem with aspiration flags to restrict entry to NA races.

GenericFlags bits (click to expand)

Bit	Behavior if toggled
`0`	Makes a car unbuyable (`NotForSell`).
`1`	Hides the last `VARIATION` (colour) entry. Used for special colour cars and the black race cars.
`2`	Makes a car unable to enter races (`RaceForbidden`).
`3`	Hides a car's specs (`HideRealSpec`).
`4`	Marks a car as open top-only, meaning it has no closed roof variant and cannot enter typical races (`OpenCar`).
`5`	Marks a car as a test car, meaning it can only drive on the Nürburgring Nordschleife, Test Course, and Las Vegas drag strip (`TestCar`).

TUNER_LIST¶

Applicable to: TT, GT4

This table links a car to a list of tuners - tuners can tune the car.

Table (click to expand)

Column	Data Type	Description
`Label`	String	The human-readable reference name for the car. Must match from GENERIC_CAR.
`Maker(1 through 10)`	Short	Maker IDs. The list of makers is hardcoded in GT4/TT.

Maker List (For GT4/TT)

Name        | ID
------------|----
-           |  0
acura       |  2
alfaromeo   |  3
astonmartin |  4
audi        |  5
bmw         |  6
chevrolet   |  7
chrysler    |  8
citroen     |  9
daihatsu    |  10
dodge       |  11
fiat        |  12
ford        |  13
gillet      |  14
honda       |  15
hyundai     |  16
jaguar      |  17
lancia      |  18
lister      |  19
lotus       |  20
manufacturer|  21
mazda       |  22
mercedes    |  23
mg_mini     |  24
mitsubishi  |  25
nissan      |  26
opel        |  27
pagani      |  28
panoz       |  29
peugeot     |  30
polyphony   |  31
renault     |  32
ruf         |  33
shelby      |  34
subaru      |  35
suzuki      |  36
tickford    |  37
tommykaira  |  38
toyota      |  39
tvr         |  40
vauxhall    |  41
volkswagen  |  42
asl         |  43
dome        |  44
infiniti    |  45
lexus       |  46
mini        |  47
pontiac     |  48
spyker      |  49
cadillac    |  50
plymouth    |  51
isuzu       |  52
autobianchi |  53
ginetta     |  54
saleen      |  55
vemac       |  56
jayleno     |  57
buick       |  58
callaway    |  59
dmc         |  60
eagle       |  61
mercury     |  62
triumph     |  63
volvo       |  64
hommell     |  65
jensen      |  66
marcos      |  67
scion       |  68
cizeta      |  69
fpv         |  70
caterham    |  71
ac          |  72
bentley     |  73
seat        |  74
landrover   |  75
holden      |  76
nike        |  77
au_ford     |  78
chaparral   |  79
autounion   |  80
proto       |  81
yamaha      |  82
kawasaki    |  83
aprilia     |  84
mvagusta    |  85
yoshimura   |  86
moriwaki    |  87
buell       |  88
ducati      |  89
_7honda     |  90
ysp_presto  |  91
trickstar   |  92

TIRESIZE¶

TireSize defines tire sizes.

Table (click to expand)

Column	Data Type	Description
`Label`	String	The internal name for the color.
`flatness`	Byte	Tire profile.
`unk`	Byte	Unknown. Possibly category?
`diameter`	Byte	Rim Diameter. Divide by 10 for inches.
`width`	Byte	Tire Width. Multiply by 5 for millimeters.

So for example, cougar_xr7_67, which uses Tire Size ID 859 (Label: sz209) in GT4:

Flatness: 12 (profile 60)
Diameter: 150 (15 in.)
Width: 51 (255mm)

Tire Size = 255/60R15.

VARIATION¶

Variation defines all the colors available for the cars. In GT4, it is also responsible for linking to the model and the color patch. In later games, it has moved to MODEL_INFO.

In GT4, in order to get variation rows you would first need to obtain it from CAR_VARIATION.

GT4 Table (click to expand)

Column	Data Type	Description
`Label`	String	The internal name for the color.
`ModelCode`	String	Code for the model to be used with the `car/` folder.
`VarOrder`	UInt	The display order of this paint color.
`ColorPatchFileName`	String	Color patch file name to be used with the `car/`. Ends with a `.pat` extension.
`Name`	String	Paint color name.
`ModelWidth`	Float	Model Width.
`ModelHeight`	Float	Model Height.
`ModelFront`	Float	Model Front.
`ModelRear`	Float	Model Rear.
`ModelProjection`	Float	Model Projection.
`ColorChip(0 through 4)`	UInt	Color of the chip for the car (the color display rectangle for menus).