Anyone using an optima battery?
 

My original battery just failed this week so I'm thinking of upgrading to the optima line. Anyone have experience using one in our x5s? Btw, battery is 5 yrs old, kinda early failure or is it normal?

Just make sure you are getting the correct one. Red Top. IF you have a stereo system, etc go with yellow top.

We have a Odyssey battery in ours - it's a beast though...

5 years is about right, lets see some pics of that 740.

From the 2nd Gen Lexus GS boards the consensus was that the Yellow tops only have a lifespan of about 3 years. That said I replaced GS430 battery with a larger capacity Duralast from AutoZone for $85 3 years replacement and 5 year prorated warranty.

If you have air shocks in the rear, an optima will not fit.

I have air ride as its a 4.8is so is it below the black hump in the center of the spare tire? I guess if an optima won't fit then I'll go for the Duralast 49L. I've had 2 of those in my 740i and they've served me well.

I have not measure the Optima but my Odyssey AGM battery fit...and this one was a beast.

Do you research, confirm the specs on the CCA, etc.
The smaller batteries do not have enough CCA. Compare spec for spec but the red top IMO is the preferred battery for DD, and the yellow top only if you have needs for more power. Can't extrapolate more as I don't have my thinking cap on, but it's the specs and you need to size/spec it right for YOUR application