I just hit 60K on my '96 AV6 and was gonna do a 60k tune-up but my dad's friend, a mechanic at Toyota for like 20 yrs said that it can be done at 70K. 90K seems a little long, especially at the threat of messing up the engine if the timing belt breaks. Just my 2 cents. But I do agree, it also depends on how hard you drive it.