I think the mechanic might not have done the fluid change than. The fluid is expensive to begin with. Second, yes you need to have it at very specific temp ranges for when you ensure the fluid level is correct. And third, the whole job is time consuming. I think he might have been banking on you not checking into it.The recommended maintenance fluid change interval for the 6 speed automatic is ridiculous and I had my local mechanic change the fluid at about 55,000 miles and it was cheap - he charged for the fluid and way less than an hour of labor. There was no temperature thingy to worry about and the Patriot runs just great.