Too much isn't good, but if it's been reading inconsistently, how do you really know it's high now (other than it's current reading)? Have you allowed at least 10 minutes of cool down time for it to level out? Something you could do is once the new filter is installed, pour 4 quarts of oil, start it to check for leaks and so forth, then shut it down. About 10-15 minutes later, check the level and see where it is. It should be a tad low, in which case I would add another .25 quart of oil (I use 4.25 quarts, or 4 litres of oil in mine). Yours may require a little more or little less.