To tell you the truth, they do drop in HP on the screen.
But go in the race and you'll see that the car still has the power.
You can check this by buying a Turbo powered car. Race it once without the Turbo upgrade, and youll see no Turbo Meter. Then, upgrade it with Turbo Stage 1-2-3 or 4. Go to arcade mode and race again. You'll still see the turbo meter there, meaning your upgrades still work.
Although, it's almost better if you don't use the upgraded cars. Because they pick your opponents by how much horses you have and not by the type of car it is. In other words, you might have a fully tuned up Trueno, thinking you will be racing against other cars in its league.
Thats where your wrong, they will put you up against Mugen NSXs, Toms Supras, and Calsonic Skylines. It doesn't take a genious to figure out that these cars would woop you up even if you had a 600 hp trueno.
(Edited by LiquidCrash at 12:46 pm on Aug. 11, 2001)