HI. The oil looked a little low when I had my oil change; I figured the tech simply put an even 4 quarts in. So I added an extra half a quart, now the driver's side of the dipstick level reads full at the highest "diamond" on the stick, but no higher.

Is this too much? How do you know if there is too much oil in the car?

 

There is a line at the top of the "diamonds" (or X's). If it's over this line, it's too much. It tells you this in the manual.

 

Thanks for the help. How dangerous is it to have slightly too much oil in the engine?

 

"Slightly" too much is no big deal. I would say anything up to 200cc to 300cc over is still OK. More than that and it can become extremely dangerous for the engine's health. Too much oil causes the bottom end of the engine to slam down into the surface of the oil and create foam and froth. Bubbly oil doesn't pump well and doesn't lubricate or cool very well. It would be like oil starvation.