After having my oil changed I noticed some oil spots in my driveway and so I checked my engine oil level. The level on the dip-stick is about 3/4 - 1inch above the (full line). It looks like they put an extra qt of oil in the car. Should I be concerned about this and could overfilling cause a leak. Thanks.

I wouldn't be as concerned about the leak as I would be about the damage that could occur from having too much oil.

If there'* too much oil in the pan, the crankshaft will agitate the oil and make it froth. The froth is essentially air in the bubbles. Too much air/oil mix (froth) will result in not enough lubrication.

Drain out a quart by using your best estimate and recheck the oil. Don't restart the engine until you bring the level down.

Ok..... if in fact there is froth in the oil and some of the oil leaked out of the car and on to the driveway, would the small bubbles (froth) be visible in the oil that leaked onto my driveway? I'll tell you why I ask. When I looked at the oil spots on the driveway, there were lots of small bubbles that converged to the center of the oil spots. At first it looked like there was some foreign material mixed in with the oil. Upon a closer visual inspection, I could see they were small bubbles.

The bad news is, I've been driving the car for about 2 weeks since they changed the oil.

Thanks for the info.

The oil leaking out is likely increased splash on the oil pan gasket. The bubbles wouldn't transfer very well in the leak, I wouldn't think.

if you remove the oil filter, let it drain from there, and drain the filter well, it'll be about a quart, maybe a little less, depending on if you have an oil cooler or not. it won't show a drop in the level until you run it for a few seconds till the void left is filled with oil.