I have a 2004 4runner with a v8 and 145,xxx miles my wife has an 2006 sequoia with 59,xxx miles.....i've decided to switch them both over to full synthetic motor oil....that said I have several friends who use full synthetic and only change their oil every 10k miles.....their oil analysis says the oil is good at 10k.....do any of y'all see any problems going 10k between oil changes.....any and all opinions are wanted and thank you....Chris