No, unless you didn’t tighten the drain plug and ran it dry or something, I can’t imagine any but the sleaziest dealers would try to deny you a warranty claim for doing your own oil (in which case you don’t want to do business with that dealer anyway). The main thing is to keep your receipts to prove that you did actually change the oil, and write down the date and mileage every time.

And, yes, I agree with you 100% on changing your own oil, and 100% that 10,000 is too long, especially for something like a 4Runner that you are expecting to keep for 300,000+ miles.  Scotty would approve.

Welcome to the forum!

Thanks for all of the replies! Since my original post I've done a lot of reading on this topic (thx to those that posted links!) and I think I've decided to let the dealer change the oil at 10K intervals (as the owner's manual and dealer recommends) and I'll change the oil myself in between those intervals. This way the 4Runner gets an oil change every 5K miles alternating between myself and the dealership. This satisfies the service requirements in the off chance I do end up with an engine related warranty claim. It also partly satisfies my anal retentiveness of making sure the service is done correctly. I swear to God if the dealership "technicians" (and I use that term lightly) over-torque my skid plate bolts or drain plug....there's going to be a scuffle!

As someone who is on both sides of the table (dealer and owner), I can tell you that the dealer can void your warranty for doing your own oil changes. If you actually read all of the very fine print in your warranty, which almost noone does, it actually states that the warranty will cover issues as long as the vehicle has been maintained by ASE Certified Technicians.

I've denied warranty before due to someone botching their oil change and not putting in the right grade of oil, the right amount of oil, not tightening the drain plug and driving with no oil, etc. and so forth. 

I had to also go through this with Ford as part of my lawsuit over my 2018 F150's oil consumption. Receipts for all services, including oil changes performed by qualified technicians, were requested by their lawyers. Receipts saying you bought oil change supplies are inadmissible in court because they do not prove the service was done....only that you bought supplies. And you can scream Moss-Magnusson all day, but unless you've got the time and money to fight a multi-billion dollar corporation for a year or two, it's pointless. 

As just one example:

https://blueovalforums.com/forums/index.php?/topic/57265-does-changing-your-own-oil-risk-voiding-ford-warranty/

I feel like this is a dealer-to-dealer thing and there's not really any one answer to it. The Ford dealership I bought my 2017 Mustang from has a Performance department, and I knew the department manager a few years ago. He he told me that unless it can be proven that a modification, etc. is the cause of a failure, then their particular dealership won't throw a huge fit about warranty work. As long as a tune, etc. was performed by a professional organization like Lund, BAMA, etc. and it did not remove certain hard engineered limits from the programming, like rev limiters, etc. then they generally won't blame the modification. They can see with their dealer equipment if a vehicle's programming has been modified, how many times the PCM has been flashed, and the dates that it was. It will be obvious to them if an engine blew up and the PCM was flashed recently as to what caused the failure. Putting superchargers, turbochargers, etc. on an engine that didn't come with them is a whole different animal. If you get a Roush Charger on a GT and they did installation, then the warranty would cover it. If not, then you wouldn't likely be covered.

As far as DIY oil changes, I feel like you can easily prove with laboratory testing whether oil changes were done at proper times and with proper oils. Oil that hasn't been changed will obviously show signs of internal engine wear, such as metal particulates, sludge, gasoline dilution, moisture build-up, acid formation, clogged oil filter... I'm not sure if you can figure out whether or not two grades of oil were mixed and removed based on residual contamination in a lab. The weight and viscosity changes after use I'm sure, but I would think it'd be well documented as to how much change is "normal" versus if there are mixed weights. 

Don't worry.  There is only a 0.0001% chance of needing warranty repairs on that engine.

And if it came to that, you would only need those receipts to win in court.

Heck, you can take a cell phone photo every time you do an oil change. 

P.S.  Those detailed records can make a huge difference if you decide to sell the vehicle in the future.

I know some people over on Corvette Forum that were denied warranty coverage for an issue with their engine because they performed their own engine oil changes (and they, too, fully documented everything and kept all their receipts).  The vehicle was completely stock, and there was no correlation either between the engine issue (GM issue actually) and them changing their engine oil every 3,000-5,000 miles.  So, they (the manufacturer) can deny a coverage, and then make you prove your case.

Changing engine oil every 10,000 miles in your case would be too long.  But, I’d probably have the dealer do the engine oil changes (request the same tech if possible).

you're right about Magussen-Moss ... it's illegal for them to deny your claim.  If you're a push-over kind of person who won't make a stink, and they sense that they might get away with it, then they might try.

It's never been an issue for me personally, but I don't buy Corvettes. In my case, they usually just try to convince me that issues are "normal"

no it wont they cant make you go to the dealer just keep your receipts like i do