Optima's were good until Johnson Controls sub contracted most of them offshore. Then they went downhill rather quickly. Far as I know, the only ones still produced at the Waterville, Ohio plant are the blue top marine batteries. My farm is about 20 miles north of them.
I just buy my flooded cell jars from a volume dealer now, in my case the local Freightliner dealer I retired from. They go through batteries like water so they are all fresh. Been using the Delphi brand, not sure who makes them but I have excellent luck with them. Personally speaking, I think Optima's are over priced and poor quality (life) today.
Neither of my Kubota M9's have a timer on the glo plugs, I just do the second count in my head and never more than 10 seconds no matter how cold it is outside. If they aren't red hot in 10 seconds, you have other issues (like a weak battery) for instance.
Mine are a bit older than yours, 2002 and 2004.
One can read that all things are "good" and on another forum all things are "bad" on the internet. Lots of experts abound on all subjects. Sometimes it's entertaining.
For my own personal experience with Optima batteries, I've never had one fail. Started buying them 20-odd years ago, and every time, they've worked fine. I put a blue top "dual purpose" marine/rv battery (blue top, light grey body) in my '74 Dodge Power Wagon that was still going strong 10 years later when I sold the truck in the fall of 2011. It always had enough juice to start up that 11:1 compression 440 big block.
I put a red top Optima in wife's Toyota 4Runner the first winter we moved up here (2011). It's still there, and never had a single issue with it. The first time it got *cold* here, it killed the original OEM battery. 11 YEARS later, that red top Optima is still in her car, and still fine. Never needed a jump or failed to start. Ever. Last year was the first year her car got to sit in a heated garage, previous to that it was always parked in an unheated garage, or in the driveway.
In the first winter (2017) I had my new tractor, the first time it got *cold*, it killed the OEM wet cell Interstate brand battery dead as a door nail. I put in a red top Optima in December of '17. It's still fine. Never needed a jump start, or had an issue of any kind. Even now, it sits in an unheated steel building and will start on the first try even at -40F. Sometimes it will go a month without being started. Never failed to start, never needed a battery maintainer, battery heater or anything.
Last week I put a red top Optima in my '12 Ford truck, after the second time the Interstate AGM I bought in '17 was stone dead due to the cold. Truck sits outside all year 'round, brand new red top started it up like no big deal when the garbage Interstate battery whimpered and died. Both times the Interstate battery puked, I went out and fired up the tractor with the red top Optima in it, and drove it over to jump start the dead Interstate.
Your "facts" that "everybody knows" don't add up.
Nothing new there.
If those Optima batteries didn't work, I wouldn't buy them. They've never failed me in 20 years. The only ones I'm done with are Interstate. They'll never get another dime of my money. They refused to replace the AGM last winter when it died, because they had to charge it overnight (in a heated shop, naturally) before they would "test" it to see if it was "bad". Well, surprise and shucky-dang, it "passed" when it was warmed up from being inside all night. This year when it died again (seems the magic "cold" number is always about -30F or colder), I didn't even call them. I just went down to Napa and bought the Optima.
I have no use for a battery that won't work at -30F or below.
