I went to a car show this past Sunday and it was not only a hot day, it was further than I normally drive. After the engine got toasty warm my oil pressure dropped to about 20#. I was driving about 55mph. I use 30wt oil and everything is ok on the engine, but it seems the pressure should be at least 30#s. It's the first time I've seen it that low at highway speed, but maybe it's normal when the weather gets hot or the engine has been running at high rpms for an hour. Does this seem right? Cecil....