I have a 2006 6.0 powerstroke with 132k miles on it. Will I be okay to switch to synthetic oil (Rotella T6) or does my truck have too many miles on it?

 

It won't hurt a thing switch if you want too.
only hurt will be the wallet for the oil.

 

Just switch, shopping around will lower the price. Any of the big names will do just fine.

 

Switching will be fine, your injectors will love you for it......I personally use 5w40 chevron delo in my 6.0 year around. I buy my delo oil at wally world and it's usually about a $1.00 to $1.50 cheaper than Rotella, I've used both in my diesel equipment for years and they(to my observation at least) are equal in all aspects.

I think it's worth mentioning the fact that my other diesels are in a JD Dozer, an Cat excavator, a JD frontend loader and currently a Mack truck, the Mack I use 15w40 Rotella, the others I use the synthetic oil in year around. I have never experienced an oil related engine failure in any of these pieces of equipment.