Well, that depends on what model and optioned Prius you have... unfortunately, rolling resistance information can sometimes be difficult to get (and compare between models).
If a NHW11 Prius (US 2001-2003 model years), there are few options in the P175/65R14 size that are of the proper load rating, so of those the only LRR is the OE Bridgestone Potenza RE92 XL, and maybe the Nokian WR or WRG2.
If a NHW20 Prius (US 2004-2009 model years), you have many more options. You can stay with the Goodyear Integrity 15" tires (OE on the base model), but you can do better for LRR. Look into the Michelin Energy MXV4 Plus, or the Nokian i3,WR,WRG2 tires, among many other options.
more info:
http://john1701a.com/prius/prius-tires_classic.htm
http://john1701a.com/prius/prius-tires.htm
You would also do better to ask other owners, and search the message archives at:
http://autos.groups.yahoo.com/group/toyota-prius/
http://www.priusonline.com/
http://www.priuschat.com/
There's a lot of myth, urban legend, and misinformation out there on hybrid vehicle batteries and vehicle production, thanks to a flawed marketing paper by CNW and a poorly researched student newspaper opinion article that keep getting quoted...
Anyhow, I suggest reading:
Hummer versus Prius: "Dust to Dust" Report Misleads the Media and Public with Bad Science:
http://www.pacinst.org/topics/integr...sus_prius.html
Is it possible that a Hummer's better for the environment than a Prius is?
http://www.slate.com/id/2186786
Prius Versus Hummer: A Nickel for Your Thoughts:
http://www.sierraclub.org/sierra/200...sp#headaches"I read an article stating the Prius has a worse impact on the environment than a Hummer because of the enormous pollution created in making the car's batteries. True?" :
http://www.straightdope.com/columns/080404.html
Giving Directions: No, the Hummer Actually Isn't More Energy Efficient Than A Prius, Let's Put This "Debate" To Rest:
http://www.betterworldclub.com/artic...-efficient.htm
Prius Versus HUMMER: Exploding the Myth:
http://www.thecarconnection.com/Auto...96.A12220.html
Heard the One About the Hummer?:
http://www.toyota.com/html/dyncon/20...mervprius.html
Usually the mythic "article" from The Mail on the nickel in the hybrid cars' NiMH batteries is quoted from a now retracted article. The retraction that clears up this bit of misinformation is at:
http://www.mailonsunday.co.uk/pages/...n_page_id=1770
(They were using data from the early 1970's about the INCO-Sudbury nickel mine, which was more than 20 years before the first hybrids needed NiMH batteries, and the plant has greatly cleaned themselves up and reforested the area since then. If you were to add up the amount of nickel in the million+ hybrids sold since 1997, that total is still less than 1% of the world's annual nickel production (far more nickel is used for stainless steel, for example).)
(Even the journalism student author of the much-quoted student newspaper article has posted a followup here:
http://clubs.ccsu.edu/recorder/edito...asp?NewsID=203 and the newspaper had to issue a clarification:
http://clubs.ccsu.edu/recorder/edito...asp?NewsID=207 )