User blog comment:Mr. Mysterious Spyman/Tuning Kits for Multiplayer/@comment-72.199.52.9-20170608173325/@comment-27736210-20170609132107

I'm pretty sure the information you have provided is inaccurate.

Percentages are not based the your total performance; percentages are based on the difference between minimum and maximum ranks. That is the reason why cars that start at lower ranks become more overpowered in Multiplayer; such as the M-B SLK Special Edition, Range Rover Evoque Coupe, Aston Martin Vulcan, and Renault DeZir. All of these cars start at lower ranks, meaning that they can be at level 5 Top Speed and Nitro, yet they will be at a low rank like 1200, which will place them against stock Class B and A cars, which will be slower.

This concept is well-known in terms of the Max upgrades and sometimes Pro upgrades.

However, the thing I am talking about specifically is Tuning Kit upgrades. Tuning Kit upgrades directly relate to the difference between minimum and maximum ranks, which is the exact thing which makes OP cars OP. So, Tuning Kits on cars like the Renault DeZir are naturally more insanely OP because the cars themselves are already OP.

A very important point is that the "difference in rank" is the difference between the starting rank and the Maximum rank. If the Pro kits take up a gigantic chunk of rank, such as 200, the difference between the minimum and maximum rank will be the highest rank with 200 rank and the original rank subtracted. The Camaro Z/28 has a starting rank of 543 and its highest rank is 1309. The Renault DeZir has a starting rank of 514 and its highest rank is 1262.

The difference between the two cars minimum and highest rank seems to be similar. However, the Renault DeZir only gets 100 from Pro kits, while the Camaro Z/28 gets nearly 300. This means that the Camaro's Max rank is only 1041 and the DeZir's is 1153. Now it starts to become more obvious as to why the Camaro Z/28 has a Tuning Kit bonus of 87, as opposed to the Renault DeZir's Tuning Kit bonus of 128. The simple conclusion you can gather from this is that the Tuning Kit bonus becomes bigger as the gap between the minimum and Max ranks of the car becomes bigger.

I have also tested this with a few cars I own, and it's basically 100% correct at this point, at least for the cars I own that have been used in testing. So this rule is based on the assumption that all of the cars are consistent.