There has been a lot of threads about LSPI ad the Gen 2 16.5-17 the I haven't seen any failures yet on the 2018 maybe GM is using stronger pistons and is why you are getting all 4 replaced.Rob - It has 25,400 miles on it. I will think about your advice, thank you. I really love the car - but I don't want issues down the road. Getting close to retirement and I don't want repair bills. I must admit, it's a beautiful car, and it rides very well. From all I've read on LSPI, it can ruin an engine completely. Unfortunately, I'm not mechanically inclined and I'm wary on how to know if this is a patch job or if fixed.
A couple things you can do to help avoid it would be
Number one Use only Tier one premium 91/93 octane fuels
Number Two Use 100 percent synthetic Amsoil, though "full" synthetic oils claim to be synthetic they start of with a petrolatum base 100 percent synthetic is just that 100%.
Gm's Dexos standard allows for oils to have up to 4 LSPI events during testing. Though Amsoil is not "Dexos" approved that is simply because Amsoil won't pay GM for licensing fees. But it had ZERO LSPI events in all of it's testing.
I know it's an economy car and I believe that's why there are issues as GM is trying to squeeze out every MPG and they don't want to recommend High Octane fuel that would defeat the purpose of an Economy car.
Plus your car will run a lot better and a little more spirited on High grade.
Some like myself have actually used a tune along with the above, tunes will be programmed to help eliminate LSPI and make the car really more fun to drive.
PS and like yourself I am getting near retirement so I don't beat on my car but love the increased mid range power the extra 63 HP and 92 lbs of torque gives me.