I want someone to talk me out of why going to Walmart and walking away with 4 brand new tires with staggered setup for out the door of $450 is not the play.
Well especially for a G90 - a $70-100k car depending on when you purchased it - cheaping out on tires is absolutely not the play. Sorry - but if you can't afford to own the car, then you can't afford to buy it, either.
That being said - remember this is a premiere luxobarge, and if you take away the trinkets of it or any other luxury car - half the reason for purchase is the ride quality. Smooth, quiet, comfortable. Tranquility when laying down miles on road trips or dealing with the insanity of rush hour and the noisy, chaotic world around you.
All the cabin isolation and ANC in the world cannot compensate for shit tires making a lot of racket... and cheap, high-mileage tires are practically rock hard with one intention in mind: longevity.
That lacking absorptive property that is engineered into quality grand touring tires is going to transfer straight into the cabin between rubber slapping pavement at 70mph and the tire's resonance making it ring like a red, rubber dodgeball. Super stiff sidewalls due to that same, single-compound rubber being used to inject the entire tire mold means you are also going to feel every separation crack in the road which can even impact handling.
Next is the grip. Sure - the rock tires might get you a noticeable improvement on MPGs, and you might be able to go several years between sets of tires, and it is likely to grip really well on dry city or interstate pavement. But rocks slide more than they grip when the rain comes - not to mention the added noise of the wet. And forget about using it in snow - even with AWD.
I've been down this road in the past with other cars, living mostly in the upper midwest for my adult life, and being in the position of having to pinch pennies on tires. Every time I did I was happy with the purchase initially, on the dry drive home. But was always disappointed later for these reasons. It either showed up on my first long road trip where I got a screaming headache due to the long-term exposure to the noise, or else in the snow because I refuse to let a few inches stand in the way of what I need to do that day (that's what she said). I can tell you that putting quality rubber makes a world of difference in these areas, no matter what car you drive. But if you want to put a $400 set on your 90, then drive over to my place, I will let you take the
wheel of even our minivan with CC2s. Don't be surprised when it then sounds, rides and handles better than the 90.
Yeah - sometimes you just gotta get tires on the car. If that's the position someone is in with the 90 - then they have the wrong car. This is a quality, grand touring car - and it certainly deserves quality, grand touring tires - as do the occupants. If you are not fleeting your cars - there is nothing to be gained by putting fleet-life tires on them.