Don't have one on my SMB, but over the years have used them on my other cars and they have been perfectly fine. Plus they have had a great return policy.
'05 Ford V-10 4x4 SMB "50" White
'00 Jeep Cherokee 4x4 Highly Modified
'04 Jeep Grand Cherokee- wife won't let me modify it. :-(
Does anyone really read this stuff other than surfgeek?
Costco does not provide ay specialized battery training, which means their batteries do not receive any different care from any of their other products. I have seen Kirkland batteries installed that had been sitting on the shelf for over 3 years (and failed normal tests less than 12 months later). AAA and Interstate don't allow more than 3 months shelf time. If you are careful, and check the manured date, not a bad deal. Just don't count on somebody else tracking stock for you.
I tried some Kirkland sealed starting batteries (don't remember the specific model / type) and only got about a year out of them. Great thing is they took them back no questions asked. Bad thing is I had to change the batteries twice in about a year. Not a very fun process on the diesel vans.
Who actually makes the Kirkland batteries? There's only just a very few actual battery manufacturers in the country, so it must be made by one that were all familiar with. If, for instance, it were Lifeline or one of the others, the performance would probably be about the same for the Costco version of the battery.
2008 RB 50 Pueblo gold, Diesel, 4X4, Aluminess