My 05 battery was showing 9 volts on the MFD... and we got the red triangle a couple of times on start up. I have read on the site that my MPG might go up with a new battery and I have picked up 4-5 MPG's. I thought my low MPG"S were due to aftermarket tires. The battery was $250 (you have to use the dealer)... a lot for a car battery but it will pay back a little every fill up. I'm gently driving to about 51mpg.