The Sultan is slow.
If you can get your hands on a duped Buffalo it is seriously one of the best. It is fast, yet has enough mass to not be manhandled badly.
I've tried out every 4 door car I can think of in the game. The Buffalo and new Oracle are two of the best all-rounders imo.
I have Franklin's Buffalo and Sultan both maxed out.
Started a sports car race to compare real performance specs... Same top speed, Sultan has faster acceleration.
Next I will buy Exmplar just to prove the other posters wrong as well.