I had an optima yellow top in my 73 dart sport and i replaced it twice, was just garbage, maybe it was just a wave of crappy ones because 2 of my buddies were having the same problem, and we lived on the central coast (pismo beach) of california, not really hot or cold weather. Never heard of a similar problem with red tops tho. I just use walmart now, no problems with the dart or in my challenger. just mt .02