I have oem battery which is Group 27 battery in my Infiniti QX56/80. I bought the battery brand new at the dealership on 7/16. It has lasted me almost 4 years now and still cranks ok, but it shows signs of dying. I got it checked at Autozone and they confirmed that it cranks just ok but power is going low every day. My offroad lights do take a toll on my battery since I use them sometimes without even turning my engine on. They are wired directly to my battery. So, I want something more powerful now to handle the extra juice my lights draw from my battery. I wanted to get the Interstate battery with 810 CCA from Costco, but the nearest Costsco carrying it is 300 miles away. The stores in my area do not carry and refuse to order it for me. It comes with 3 years FREE replacement. I went to Walmart and almost got the Everstart Maxx with 810 CCA. It comes with 3 years FREE replacement. I changed my mind and said I will take some more time to decide. I am leaning towards experimenting with something else if it will work. My small and basic research has shown me I could be able to make the group 31 battery fit. This battery is larger in size to my group 27, though I believe I can make it fit my battery tray. So, my goal now is to purchase this Interstate Battery that I can get locally here for $169 plus tax. It has 950 CCA. Warranty on it is only 1 year free replacement, but I am hoping it would last me more than 3 years. Since my basic oem lasted 4 years, I hope this Interstate which claims better specs than my basic oem, would last too atleast 3 years. What do you guys think about replacing my group 27 batteries with the group 31 battery. Will it be ok or not wise to do? Also, I have read a lot of good things about Interstate. I hope if I buy this battery, it can last more than 3 years. That is the point at which I believe I would have had my money's worth and will not be mad if it dies after that. Since my basic oem can give me 4 years. And the Walmart group 27 offers 3 years free replacement.