So I just buy appliances from Costco and assume I will have to replace sometime after 4 years.
As one data point, all of my LG Costco appliances from almost 4 years ago are still working fine, through very heavy use. We probably use washers/dryers 10+ cycles per week due to babies/toddlers. The LG inverter linear compressor fridge is still as silent as the day we got it.
If Speed Queen’s data showed them their machines lasted 40 years, then they would advertise them with a 40 year warranty to maximize sales.
Since they do not, it is safe to say that Speed Queen does not want to bet their machines will last 40 years. So why should I bet they will last longer than their stated warranty period?
It is possible that Speed Queens are worth more because they are more repairable, but I have no interest in spending my time repairing my washer/dryer. And calling a technician would be $100/hour plus parts, at which point I might as well buy a new machine.
in other words, if BrandX had products they believed would last 40 years, they would have a warranty that says so, and it would not decrease the reliability 1 iota
Also, longer warranties can be a selling point (speed queen does this with the same exact internals being sold with a higher warranty on the 'fancier' ones which just add some more features to the board).
And, a company has to hold monies on the books for warranty service, so a defined warranty period that is not unreasonable can help with that.
But the "best" company in a given market only needs to warranty beyond the nearest competitor.
Speed Queen also is implicitly dealing with people who would buy the "lifetime" warranty residential unit and run it in a commercial setting, where the wear parts would wear out.
If the Speed Queen cost 50% more, I would be inclined to buy it. But at 3x the price, I feel like it’s just easier for me to replace, and since it is Costco, I trust that the process will be easy.
Wouldn't that mean they should have longer stated warranty than estimated lifetime?
There is little enforcement of warranties from the FTC. They cannot afford to do investigations, because they are civil litigation.
If the manufacturer doesn't like it, they get dropped by Costco like a hot potato.
For what it's worth, the Speed Queen washer/dryers people seem to like, appear to also share parts with Maytag [1], which means Whirlpool made, or uses, or shares at least designs for parts, even though Speed Queen is owned by Alliance Laundry Systems, who also make the Huebsch machines in apartments, which, are commercial grade, but still not free of problems (i.e., >half of front loading machines in one place I've been in have the marbles-in-bearings sound when spinning, which a newly replaced machine didn't)
Some models of Speed Queen washers I've seen people open on YouTube look suspiciously like a Whirlpool "direct drive" 90s washer.
[1] https://ibb.co/PzQxxP6 - I searched for "speed queen transmission" on DuckDuckGo Images and found this listing that mentions compatibility between that and Maytag. I also recognize that transmission as a Whirlpoolish thing.
Given that most appliances around me are made by Whirlpool, I don't personally have anything to compare them to. I haven't personally seen many extreme design flaws, but the parts are built down to a cost. For example, all of their dryer motors are epoxied together instead of bolted, like every other motor, probably to save cost at assembly, and conveniently prevents oiling and servicing of the bushing/bearing. The washer pumps for the aforementioned "direct drive" washers are sealed, and if something gets jammed, you can't take them apart to unjam them (though I've unjammed one before, and they don't cost much, and there is a ~good reason to seal it shut).
However, whatever evils, if any, Whirlpool puts into their machines, at least you can get the parts, and compatibles exist, and junkyards are probably full of compatible parts, simply because the parts are all shared between most Whirlpool appliances in existence.
I've had one example of a bad experience with the electronic controls on a Maytag front load washing machine. I don't consider a single sample to be representative, but the software on the control was poor and refused to spin-dry a blanket after washing it. It wasn't because the machine was unbalanced. It would rotate the blanket very slowly (zero shaking), and just decide not to do anything else. It eventually did it after a bout of unplugging, pushing buttons, and cursing.