Just purchased a CX-9. Only my second Japanese vehicle. I keep my vehicles forever, do all the maintenance myself, and hope to do the same with this vehicle.
Here are the vehicles I have had over the years and the mileage before I got rid of them.
1984 300ZX - sold at 185,000 miles....replaced brakes and an alternator
1998 Audi A4 - sold at 150,000..replaced brakes and a control arm
2005 Mercedes Benz ML-350 - did the EGR at 40k, water pump at 80k, Front shocks and crankshaft position sensor at 100K, A/C Pulley Bearing at 105K. Vehicle has 118,000 right now and I have no intention of getting rid of it...
I have read a lot about problems like transfer cases and water pumps, so I'd like to feel good about this purchase and have some people weigh in some super high mileage vehicles!!!!
Thanks
What generation CX-9 did you get? This is critical as they are built differently. Because in this case, how long the 1st Gen CX-9(2006-2015) lasted, will not be very indicative of how long the 2nd Gen will last, they were built and designed with completely different critical components. I explain below.
1st Gen, used a Ford V6(either 3.5 or 3.7liter depending on the year), with a Ford designed AWD(Totally flawed design, as it seems 10 out of 10 of them failed due to the transfer case, and when the driveshaft seizes up, it could take down the transmission and or engine down with it as somethings moving and something is locking up). The Ford designed V6 was known to have some water pump issues later in life as well. There might be some other minor quirks, I've read about A/C going in and out later in it's life, etc. You might have a decent outlook if you bought the FWD setup(as most of the major problems: Engine/Transmission stemmed from the transfer case in the poorly designed AWD system), I've briefly read that some backyard tinkerer's tried to make fixes for the AWD transfer case to make it work, since if it was replaced with a new one, the same result would happen down the road, this affected many Ford vehicles with this AWD setup as well.
2nd Gen, totally Mazda designed in Japan, uses the 2.5 Liter Skyactiv motor with a dynamic pressure turbo with a Mazda designed AWD system. Foresee-ably more reliable, though time will tell, Mazda is usually pretty thorough in their testing with their testing mules, though things can still be overlooked. The transmission is built by Aisin of Japan, one of the best automatic transmission makers in the world(they make all of Toyota automatic transmissions, some of the older torque converted Audi transmission, and in the recent past they built virtually all of VW/Audi/Porsche's manual transmission... this is just to name a few... what makes Aisin legendary in general, is that the transmissions seem to be thoroughly test, overbuilt, and well manufactured/designed/engineered, one of the most legendary transmissions they built stock was the Supra MK4, stock that transmission was able to take 800+ lbs/ft and 800 whp... talk about overbuilt.)... having said this, Mazda did do some hands on designing with the Skyactiv automatic transmission, so we'll see how well it holds up.
As for spark plug changes, it really depends on what the vehicle was shipped with, generally luxury brands shipped with more expensive Iridium plugs and recommend OEM(because they are also Iridium) in order to achieve those high mileage intervals. Mainstream brands sometimes give them Platinum (last around 50k miles)or sometimes Iridium(last around 100k miles). I personally still have my stock Iridium plugs on my Mazda with close to 140k miles on them... granted I inspect them often and clean them by spraying them down with carb cleaner, give them a mild scrub with a nylon brush(never use a steel brush! That'll damage it for sure) and then torching them until all the carbon is burned off... people may argue "this doesn't work cause...", but it does, and I'm not telling anyone to do it as well, do it on your own risk, but my plugs are still going strong with no misfires, others do it as well, the only sign of wear I had was the carbon building on the tips, which I cleaned off. Disclaimer, again do it on your own risk, I'm not recommending it. If your plugs are already fouled and deformed, then you have other issues and "restoring" them won't work.