This page aims to provide a full methodology for how vehicle testing is carried out by Broughy1322 in GTA 5, in order to find the top speeds for each vehicle that are used in his videos and on this website. Start with this video for frequently asked questions.
Written by: Broughy1322
The highest constant speed a vehicle can achieve after acceleration has stopped determines its top speed and its place in this list.
Speed = Distance ÷ Time
Five testing runs were done with each car, keeping as straight a line as possible between the two checkpoints. This section of road was chosen due to it being one of the most flat, straight, and smooth sections of road in the game with a long run up. All of this ensures the cars are going at their actual top speed throughout the course of travelling between the two checkpoints, which is the only point at which measurements are taken.
The footage for all five runs was then added into video editing software and analysis was carried out to find, to the frame (1/30th of a second), how long each car took to hit the second checkpoint after hitting the first for each run. The maximum variance in all results for any car was 2 frames (which leads to a maximum standard deviation of 0.25 mph), but the majority were identical. All of these times were then averaged to get a single value for time taken to traverse the distance for each car.
These times and distances were plugged into the standard equation to find the speed of each car, and that value was then rounded to the nearest 0.25 mph (km/h values were also rounded to the nearest 0.25). This was done because that's what I feel comfortable with reporting, given the variability in testing error, taking averages, distance covered, and frame rate considerations. To attempt to be any more accurate than that is an exercise in futility using this method and would only serve to report what could be incorrect conclusions.
One thing to point out is that there are a lot of variables when it comes to top speed in GTA Online which could lead to different (and higher) top speeds in various circumstances. However beyond all of that is the fact that in-game speedometers and other forms of speed measurements either don't work or at the very least are inaccurate (see here) so if you're basing your own observations on that then you will most likely be getting wrong results.
This testing has been done to minimise variables as much as possible and make it repeatable/verifiable. Anybody should be able to repeat this testing on the same track and find the same results. However individuals may find different results to this if they're testing in a different way, such as going uphill or downhill, taking advantage of kerb boosting (see here), racing against others online (never an accurate determinant due to connectivity and variation in driving), using mods or single player abilities, and even using the left stick too much to correct the steering whilst trying to keep in a straight line. Even different road surfaces can have an effect (see here). I am simply reporting the actual top speeds of these cars when fully upgraded, on a flat regular road with no external factors and identical testing methods. Most tests were carried out on PS4 with a small number on PC at 30fps. You can download the track I use for these tests here (although it is easy to recreate): PS4.
If you do find the series helpful, entertaining, or want to be kept up to date on any car performance changes as GTA Online develops please do subscribe, like, comment and share - every little helps! You can also directly support the creation of more of these videos in a number of ways shown here. Finally, for a comprehensive spreadsheet on GTA 5 vehicle performance that includes all the values of lap time and top speed I find, alongside other vehicle info, click here. Thank you very much for watching and I hope to see you on a future video soon :)