Lately my car seems to perform alot better when I have a full tank as opposed to when it's at about a quarter or even a half. It is definitely a noticeable difference. It gets up quicker when the tank is full which seems weird since the car is carrying more weight. Is this a sign of a fuel pump that might be going bad or what? Any help would be appreciated.

 

I noticed that in my last rex. I think it is just when you have more fuel, you will get more in the engine, provided when you have a 1/4 tank the gas is sloshing(for lack of a better word everywhere...

or maybe I had a bad fuel pump too

 

The way the pump pickup is in the tank, the fuel pump doesn't have to work as hard to get fuel to the engine as it would if the level were lower. If you have a high mileage engine, and you have a severe drop in performance with a lower fuel level, you're probably due for a new fuel pump, You can go back stock or upgrade, really doesn't matter, the stock fuel pump will support up to around 300HP, though obviously being strained pretty hard to do so.