If you're looking for an Optima battery for an '80's XJS, you'll be told the D35 is one possible replacement.

The only criteria they seemed to use for this was the "reversed pole" terminal configuration.

The stock Jag top bracket will simply slide over the top of the D35 on all four sides.

However, the slightly larger (in size and capacity) D34 is a perfect fit.

The only downside is that the poles of the battery are a little forward of center, but this was not a big problem in my 1984 model.

I chose the yellow-top Optima because of its starting/deep cycle dual application. This car has always been hungry for amps, and since the electric radiator fan tends to run on for awhile when the car is parked, thought this battery might be a good choice.

I'll report on my experience with it as time passes.

Lou