Is it safe to overfill my crankcase with oil?

A lot of times I see people on the message boards that mention they got their oil changed at a dealer or fast lube place, and the person had put an extra half quart of oil in their engine, and if it was necessary to drain it out. In most cases, no, it is perfectly safe! Car makers have a bit of leeway in their specs, so if they tell you that your engine needs 4.5 quarts of oil at oil change time, you can almost always safely put in an even 5 quarts. Case in point, my 98 Corvette specifies 6.5 quarts, but I routinely put in 7 quarts at oil change time, and have even gone as high as 7.5. In the manual it does mention that it's safe to add one extra quart when racing though. In my wife's Honda Civic, the manual calls for 3.6L of oil but I've gone as high as 4.4 with no problems. What are the benefits of more oil you ask? By having more oil in the engine, it reduces the overall stress on the oil, so you'll have lower oil temps in the summer, and your oil will not degrade as fast. This is one of the reasons why a lot of European cars have such long oil change intervals, because they also have very big oil capacities too (some of them holding 7-12 qts of oil!) So I'm not saying to go right ahead and start adding an extra couple of quarts of oil, but simply start out by rounding off to the next highest number and go from there. I've heard a few experts mention that one way to tell if you've added too much, is to immediately pull the dipstick after you've shut off the engine, and if you see tons of tiny bubbles on the dipstick, that means your crankshaft is hitting the oil and aerating it. But as I mentioned earlier, there is typically a bit of leeway between the spec the manufacturer states in the manual, and the point at which the crank would actually touch the oil and cause a problem.