GTA Wiki:Manual of Style/Vehicles/Speed Testing

This article covers how vehicles should be tested in the HD Universe of the Grand Theft Auto series to gain "observed" specifications.

Descriptions
While files in Grand Theft Auto IV and Grand Theft Auto V indicate all the performance and handling data for vehicles in the respective games, what is tested in-game can differ from what is defined in these files. Handling.dat (.cfg in earlier games) defines essential qualities of vehicles such as the weight, top speed, transmission, clutch speed and buoyancy. On the GTA Wiki, we display these details on every vehicle article that follows a tag " (Handling.dat) ". This indicates that the speed, weight or gear-number listed in the performance overview table has come directly from the handling.dat files. While it is believed these files define what the vehicle performs like in-game, these details are only raw, meaning other factors, such as gravity, weight, and traction, can all effect and change these details. Because of these factors, we display two details; handling.dat (as mentioned), and "Observed". Both the GTA IV Overview tables and GTA V Overview tables have a "Defined" and "Observed" section. "Defined" indicates what is written down (or stated otherwise) in-game, such as the handling.dat files or a website claim. "Observed" indicates that a test has been run in-game to get the required details.

Grand Theft Auto IV
For Grand Theft Auto IV, numerous modifications can be used to indicate the speed that a vehicle is traveling at. We use the most basic modification to get the most reliable results. These speeds come directly from the handling.dat files, except they also take into consideration the aforementioned factors (such as weight and traction) and output the actual speed. In GTA IV, the Handling.dat and "Observed" speeds are usually almost identical due to the nature of the physics in-game, however, some lee-way can be seen in numerous examples.

Vehicles are tested by using the longest straight, flat road possible. On the GTA Wiki, we use Columbus Avenue for its notoriously long stretch of blocks. When we test vehicle acceleration, top speed and gears, it is essential we disable traffic.

Depending on the vehicle, the top speed usually fluctuates a couple of mph, so for this, 3 tests are run, the same distances, then the 3 results are added up, and divided by 3 to gain a mean speed. We round to 1 decimal place for accuracy.

For acceleration, it is best to test up to 5 times, and again, work out the mean speed. A stop-watch can be used to time the acceleration rate.

Gears can be counted without any use of modifications; the number of shifts heard (+1 for the 1st gear the vehicle is in when stationary) is the number of gears the vehicle has. When the engine begins to struggle to rev any higher, that indicates there are no more gears left to shift to.

Grand Theft Auto V
We test Grand Theft Auto V in a slightly different way. Because of the introduction of First Person Mode in the enhanced (Xbox One, PlayStation 4 and PC) version of GTA V, we  do not  use modifications to exploit the vehicle speeds. Why? Well, what is the point exploiting the game's top speeds if we are provided with the First Person Mode Speedometers which do the exact same thing in a legitimate way.

For a test to be valid, the player must be using the First Person Mode on a next-generation (or PC) console. Again, the longest road possible in-game is prefered to do the test. For the best results, using the Content Creator and creating a race on the longest, flattest road possible (preferably the Interstate 2 for its flatness, or Interstate 4 for its length and size). The player must enter First Person Mode to view the Speedometers of the vehicle. The player must then test as normal; taking note of the highest speed read on the Speedometer.

For gears, we test using the exact same method as GTA IV; counting the number of gears shifts, starting with 1, until the revs begin to level out and the engine produces no more output to give the vehicle any more speed.

For acceleration, a timer must be used, using the First Person Mode Speedometers, and testing 5 times. We use 0-60 mph (or 0-100 km/h) for these acceleration rates in both GTA IV and GTA V.

What is the difference?
What is the difference between Handling.dat and Observed?

As already stated, Handling.dat lists raw-speeds for vehicles, meaning what is seen in-game does not necessarily match what is defined in these files. The difference between the two speeds increases as the performance of the car is increased. For example, the Adder in Grand Theft Auto V is stated to have a top speed of 99 mph (160 km/h) in the Handling.dat files, however, the in-game First Person Speedometer top speed is 140 mph (225 km/h), showing a large difference of 41 mph.

IMPORTANT
The following notes are important to be read.
 * "Observed"/"Tested" = tested (with Speedometer modifications in GTA IV, and First Person Speedometers in GTA V)
 * "Defined" = anything defined in-game. Websites and Handling.dat files are listed here.
 * "(Handling.dat)" = Handling.dat data.
 * Handling.dat speeds are  raw 
 * Handling.dat speeds are listed in km/h, so the format listed in the Overview table of Performance sections will require a km/h to mph converter to write it in the correct format on the GTA Wiki.
 * Adding any speeds to the GTA V Overview table that required modifications to obtain is against the Official GTA Wiki Policy.
 * Vehicles that lack First Person Speedometers in GTA V must not use modifications to obtain a speed; they should be left blank with a clear reason why.
 * On all Overview tables in Performance sections, the mph number is first, followed by the km/h number. E.g. 140 mph would be written as "140 / 225" (140 mph in km/h is 225). The section lists the metric/imperial systems used and therefore "mph" or "km/h" do not need to be written after the numbers in this format.

Questions?
Contact any Member of Staff who will either help or pass you on to another member of staff who can answer your question. Alternatively, post a question on the Talk Page of this article.