[chassis]

Do a 10 year analysis.

Leasing for 10 years, or purchasing a new vehicle every 3 years is an easy calculation, as it relates to depreciation and financing cost. It's safe to assume the vehicle is always under warranty, so therefore no repair cost, other than oil/filters, tires, brakes, etc.

For the purchase outright, and hold for 10 years, the depreciation and financing cost (if any) is easy to calculate. The out-of-warranty repair cost is hard to estimate. Need to have a feel for it, based on experience.

DIY is a big part of owning a vehicle to old age and high mileage. I have done many repairs myself, but also have had the dealers do a bunch.

Pre-2005 (approx) Toyotas, i.e. RAV4 and 4Runner, will literally run forever if the maintenance is done. I ran a 2011 VW Touareg to 238k and it was great. Lots of diesel related repair cost but so what. Even mid-2000s Nissans can be run to 200k when keeping up on maintenance.

I have run other vehicles over 200k miles and 14+ years. It's a good financial equation, mainly if you DIY.

I am not concerned about running the G01 X3 xDrive30i to high mileage. The B48 engine has been around for a few years, and does not have radical technology. Direct injection, turbo, and 0.5 liters per cylinder is a low risk configuration. The ZF 8HP is a stellar gearbox. The unknowns for me are the instrument panel electronics, including iDrive. And body related items like the pano roof, electric seats, and other gadgetry.

Looking forward to the journey!

p.s. Agree with the comment that if you want to buy a new car, buy a new car. But don't fool yourself into it by coming up with a calculation that says you "should" do it.