2005 SuperCrew 2WD
Stock tire size = 265/60-18
new tire size = 275/55-20

Do I need to recalibrate?
Thanks in Advance.

 

265/60-18: 30.520" diameter, 661 revs/mile
275/55-20: 31.909" diameter, 632 revs/mile

Yes.

http://www.csgnetwork.com/tireinfo4calc.html

 

your new tires are 31.89" overall, and the old ones were 30.60". when i went from a 17 to a 20 inch rim the difference was ab the same as yours. my speedometer shows me going ab one mile faster at 60mph and ab 2 miles faster at 80 mph so i didnt feel it was that necessary to change

 

I'm not sure where the the "line" is when going to a taller tire, but when I went from the factory 20" to the 305/55-20, it was enough to cause my transmission to shift erratically. It never knew which gear it wanted to be in since it "thought" the tires were a certain height, yet the revs were not matching what the computer was expecting.

The simple solution was an Edge Programmer.

Now everything works harmoniously once more.