Hay I'm not here to fight with you, and i do agree that what the manual states does seem excessive, but I'm only stating what the Toyota factory service manual listed as their service intervals. Now, per the manual, if you operate under conditions of maintenance schedule "A", the service intervals become even shorter. They list replacement, or change at every 12 months, or 12, 24, 36, 48, 60, 72, 84 and 96 thousand miles of operation. Conditions for schedule "A" are, towing a trailer, or car top camper, repeated short trips with outside temps under freezing. Extensive idling, low speed driving for long distances, operating on dusty, rough, muddy or salt spread roads. All in all if you followed these maintenance schedules, it looks like a great money maker for the dealership service department. On the plus side your truck would be in great shape, the same can't be said about your wallet.