$400+ later, everything works again. Speedo sensor went out first, causing ABS to stop working (light on), then check engine light on due to ABS fault. Dealer covered part of the cost due to the low mileage, so I took the difference and went with the synthetic. Hated to pay dealer prices, but the wife likes the dealer (her van, her money) and so far they've been fair. 2 other mechanics I went to just scratched their heads and said they'd never heard of it, but that it was possible - not a real confidence booster. I also didn't want to hear "I told you so" if something went wrong.

I'm still trying to figure out the reason for such frequent fluid changes though. <img src="/forums/images/graemlins/confused.gif" alt="" /> I've never owned a truck requiring service at 12K.