I bought a used 2008 Prius in 2010 that has slowly gone from 48-50 mpg to 40 mpg and the battery indicator showed loss of charge happening much faster than when I bought it. I read about Greentec online and finally called to purchase the 4 year warranty replacement battery pack. Upon receiving an out-the-door price I ordered the battery with installation at the Auburn, WA. facility. Within 5 minutes I had an e-mail invoice with a price $400 cheaper than quoted due to the summer sale (what a nice surprise). Within about 3 hours, Gaven from the Auburn facility, called me to set up an installation time and suggested it could be done that afternoon. Since I live 71 miles away I elected for the next morning at 9:00 am. On arriving this morning I found Gaven and another individual ready to go to work. 30 minutes later I was back on the road again headed home. Wow that was quick. I shortly could tell that some of the old pep I had been missing was back again as the engine performance came back to life. After putting about 100 miles on the new battery from my trip home I found I am averaging 51.2 mpg. Wow, I never expected this kind of improvement from a battery replacement. I never write reviews for anything but because of this incredible improvement wish to finally endorse a company and product. Thank you Greentec Auto.