I also suggest a 49-series. The 4.5 can use the CCA power of the big battery. Fastlane does not sell batteries as they cannot ship via UPS or Fedex or USPS due to shipping regulations. I have an Exide in my 4.5 but it was one of the older-style Exides (I think it was made in Reading PA if I'm not mistaken?) Newer ones are mucho garbageo. I dont think Optima makes a 49 series (I didnt see it on their site).