What does the door jamb sticker say? Does it specifically list the tires as "94V"?
The only downside to that is you're sometimes locked-in to buying V-rated tires. Fuel efficiency and higher speed ratings don't typically go together, unless for a very specific OEM fitment like this. Other 215/55R17 94V tires will probably not give the fuel efficiency that the OEM tires do. That statement is often true for other speed ratings also, but seems especially the case as the speed rating goes up.
The only downside to that is you're sometimes locked-in to buying V-rated tires. Fuel efficiency and higher speed ratings don't typically go together, unless for a very specific OEM fitment like this. Other 215/55R17 94V tires will probably not give the fuel efficiency that the OEM tires do. That statement is often true for other speed ratings also, but seems especially the case as the speed rating goes up.