How to change the rate of decrease in a variable in the update function

My truck has fuel, and I wanted it to decrease slowly. In side a function I defined to draw the fuel gauge, which is called in the update function, I had this simple line: gameLevel_001_Fuel -= 0.5. Everything worked fine, the gauge in the game displayed the right amount of fuel, but it drained WAY TOO QUICKLY. Simple fix I thought, just make the value smaller. Only problem was that when I changed 0.5, to 0.05, the rate at which it decreased didn’t change. I tried 0.000005, same rate. I even tried calling it directly in in the update function. Maybe there’s a better way to have it decrease as time passes?

function SetGuages() { //Called immediately in update function
	
	gameLevel_001_Fuel -= 0.05;
	
	if (gameLevel_001_Fuel > 94){
		fuelGuage.renderer.material = fuel_100;
	}
	else if (gameLevel_001_Fuel > 87){
		fuelGuage.renderer.material = fuel_094;
	}
	else if (gameLevel_001_Fuel > 81){
		fuelGuage.renderer.material = fuel_087;
	}
	else if (gameLevel_001_Fuel > 75){
		fuelGuage.renderer.material = fuel_081;
	}
	else if (gameLevel_001_Fuel > 69){
		fuelGuage.renderer.material = fuel_075;
	}
	else if (gameLevel_001_Fuel > 62){
		fuelGuage.renderer.material = fuel_069;
	}
	else if (gameLevel_001_Fuel > 56){
		fuelGuage.renderer.material = fuel_062;
	}
	else if (gameLevel_001_Fuel > 50){
		fuelGuage.renderer.material = fuel_056;
	}
	else if (gameLevel_001_Fuel > 44){
		fuelGuage.renderer.material = fuel_050;
	}
	else if (gameLevel_001_Fuel > 37){
		fuelGuage.renderer.material = fuel_044;
	}
	else if (gameLevel_001_Fuel > 31){
		fuelGuage.renderer.material = fuel_037;
	}
	else if (gameLevel_001_Fuel > 25){
		fuelGuage.renderer.material = fuel_031;
	}
	else if (gameLevel_001_Fuel > 19){
		fuelGuage.renderer.material = fuel_025;
	}
	else if (gameLevel_001_Fuel > 12){
		fuelGuage.renderer.material = fuel_019;
	}
	else if (gameLevel_001_Fuel > 6){
		fuelGuage.renderer.material = fuel_012;
	}
	else if (gameLevel_001_Fuel > 0){
		fuelGuage.renderer.material = fuel_006;
	}
	
	
}

NVM, I’m a dunce… It’s because gameLevel_001_Fuel was an int variable, not a float. God I’m ashamed… I’ll leave this up though, so people even less experienced than me can see how crucial it is to use the right var types.