Andrew, I have a RED top Optima in my car also. However, it is the second one! I had to get it warranty replaced at 16 months in service because of a dead cell. Just my luck, the guy at the counter said I was only the second person that they had ever had to do a warranty replacement on an optima before. I happened to be in a local Batteries Plus store A few weeks ago. Just out of couriosity I asked the store owner, what the difference was between the regular Optima Red top and the Yellow top Deep cycle. Because I was thinking of maybe doing the same thing. He explained to me what the difference was inturnally between the two. He explained the differences of constuction and how a Starting (RED) top battery works as opposed to the Deep Cycle(Yellow) top battery relative to current flow thru them. HE was the one who recommended NOT to use it as a starting battery. I'm no Battery expert. But I have to consider him to be the knowledgable source on the matter. Btw. when you purchased your battery did you install it or a serivce shop? You might want to check the warranty to see if its covered in your application of use. BTW:He never said you couldn't use one. He just recomended not using it and explained why. I'm just passing the info along. Dennis 5180 To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/