I asked the Toyota dealer about this at my first oil change which was at about 4000 miles. He said there was no problem with it. I check the oil each week and it does use about 1/8 of an inch on the dip stick each week. I just add oil. My 06 Camry is rock solid and never burned oil. I had my oil changed at PepBoys and the mechanic warned me that Toyota Highlanders use oil and to keep an eye on it. A mechanic on a youtube video said it was a known problem and it's a problem with the pistons/rings.