Also if there are any engine issues and you cannot prove oil changes were done (receipts for oil does not prove there was an oil change done on your car) they can void your warranty. Happened to a guy's speed6 on 6Crew. We saw/heard his engine blow up at a meet by simply revving his engine. He couldn't prove he did oil changes, he had to pay for a new engine.
I bring my own Mobil 1 0W-20 synthetic oil & Mazda OEM filter to the dealer for oil changes & the charge me ~$8 in labor & disposal fee. Get the 30 point inspection too where they check brake pads, tire wear, battery, fill windshield wiper fluid.
For $8, I'm not climbing under the car & getting my hands dirty. Especially in the winter. Plus no potential to void the warranty. I changed the oil at 5k & 10k miles. Dealer puts the mileage at 7500 later in the sticker. But we drive ~5k every 6 months, it's long enough interval to change the oil.
Well I'm going to disagree. A dealer stole two lugnuts off my Isuzu. I have NEVER lost a lugnut, yet I lose one at the same dealer during two consecutive visits (btw Isuzu lugnuts are hard to find). I use an impact wrench. They tried to tell me it was due to vibration. Whatever.
Also had not one but two tired come out of the dealer shop with screws screwed into the sidewall. How does that happen unless someone physically put them there?
Let's see, I've had the toe on my front end "adjusted" without my knowledge ruining tires, the balance of various tires messed with (removal of weights), one of my plugs swapped for a platinum tip Bosch that was not even recommended for my car (just one!), stuff stolen from my car, etc etc. When you take your car to a dealer or a shop or anywhere you have no idea what they do to it.
As far as slurry its there. As a machinist and 5axis expert for aerospace, I know all about tolerances down to less than .000039". You responded to have them do the oil, which means you don't. If you did you'd know. I just did my brother's new Chevy Malibu with 2k miles. Care to guess what the oil looked like?
As far as the warranty I agree they can play foul with the Fumoto, but I don't expect my engine to blow up on me. Having worked on my own cars for many years, I expect I'd know if the oil drained out or there was a serious problem, ahead of time.
I'd rather save the $8, AND spend more time at home instead of a waiting room. The fumoto is more about staying clean.