and you will find alot of discussion - some pro some con. I put an "orange top" (not really orange anymore) optima in my 500e - it has the reversed terminal which match up to the 500e set up better than a conventional. I got it because I wanted some insurance against acid leak. It's foot print is smaller so the hold down needs some help. The car doesn't get used in winter, so I have a cut off switch to quick-disconnect the battery. Costs $30-50 more than a conventional. Is it worth it? I honestly don't know - I'll have to see how long it lasts.

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1992 Black 500e
1991 Black 300te 4m
1992 Black Renntech 620sl
1979 Porsche 911sc targa