That's just pouring money down the drain IMO. My dad had a couple of Mercedes C-class cars back in the 90's and the factory maintenance schedule called for full synthetic oil changes every 7500 miles. As a matter of fact I have been so busy lately that I didn't get to my most recent oil change on the 4-runner until a little over 7000 miles and I doubt it made a lick of difference except to irritate me that I am now off my usual easy-to-remember 5000 mile odometer check.
My rule of thumb;
Semi-synthetic in every car.
Full synthetic in my modern bikes
Conventional in my older (pre-1990) bikes.
Rotella in my diesel RV.

In my '97 with 289k - Lucas Long Drain 15w40 with a full quart of Lucas HD Stabilizer. Every 5k, it loves it.

In my '07 with 175k - I'm about to do my first one. It's been on Quaker State UD 5w30 for years with the PO, but I may do Mobil1 or Long Drain again since I've had good luck, but 5w30.

05 v8 with 239k miles. Been serviced at Toyota with Valvoline synthetic blend its whole life by previous owners.

I do the oil change on my own and used Valvoline high mileage synthetic blend 5w30 with a Toyota oil filter. I like to change it at 5k miles. Oil came out still fairly clean and no leaks even a this mileage. No reason to switch to full synthetic.

heres something i read recently on a tacoma forum.....

in the v6 1grfe engines, toyota actually says to NOT use synthetic oil. it was in a toyota bulletin or document someone posted & specifically said these v6's should not use full synthetic... not sure why, but it was pretty clear toyota said it for some reason.

anyone heard that before or seen the document too? maybe its seepage or leak related?

im a full believer in synthetic oil being better than normal oil... but theyre are some engines that dont like it or not designed for it.. example is older v8 engines with flat tappet lifters/cams, the lifters wont rotate in their bore like they should due to the decreased friction from synthetic. & older v8s like that with older tech gaskets & high miles can definitely have leaking issues on synthetic.

just something to reasearch & think about for the v6 & synthetic oil.

My v6 '04 has 197,000 miles. This truck continues to amaze me with its reliablity and CAN DO attitude. LOL

I've always used 5w-30 synthetic oil. Usually Mobile One, but not too committed to brand.

I'm approaching 10k and will likely be going to Castrol EDGE Extended Performance 0W-20 from the OEM Toyota synthetic oil when the time comes. I have always liked Castrol oil.

I hope to do oil changes every 8-10k since I do well over 20k every year, so only doing it 2-3 times a year will be great!

Well that's really strange since Toyota them selves (dealers) use Toyota branded synthetic oil for their oil changes?

Synthetic should be fine for any car, its only switching to synthetic in high mileage vehicles it can be an issue. If you use it from the start it should always be fine.

Maybe i am missing something?

489 miles on my 2020 and I use toyota assembly line OEM fill.

LOCAL STEALERSHIPS ALL USE MOBILE 1 FULL SYNT. FRieken caps lock.

yes toyota has synthetic oil since many of their other engines specify it, but the v6 in 4runners & tacomas etc, there is a document saying to not use synthetic but no explanation as to why.

i will see if i can find it again, but im sure others on here have heard of it too.

But they put it in there 4 Runners at the dealer and it comes with it? Would love to see the documentation for this.

I looked for the documentation and the only thing i could find is the 5,000mi oil change vs 10,000mi oil change and how the 4R's are not designated for the 10,000mi oil change which makes sense since its an off road vehicle.

Don't know what year this was written:

Toyota Parts | Synthetic Oil Good or Bad for Toyota Vehicle
"*The 2TR-FE (4Runner / Tacoma) and the 3UR-FBE (Flex Fuel Tundra / Sequoia) are the exceptions to this new change interval program; these engines have not been approved for the 10,000 mile interval at this time. A 5,000-mile/6-month oil change interval is still required for these vehicles. Also, the Flex Fuel 3UR-FBE requires a 2,500 mile interval when operated on E85."

based on everything ive read for 4th gen v6 says 5/30 conventional was used untill roughly 2010. i dont think 4th gens come from the factory with synthetic. after ~2010 they use the 0/20 which is a synthetic from toyota.

ive seen the 5000 vs 10,000 oil change documents too, also have read the one about using 0/20 in some v6s after 07 or 08.

but the one i read within the last few weeks was posted on a facebook toyota group & was an official toyota document or TDS & it clearly said the v6 in 4th gens & tacomas prior to 2010 should use conventional 5/30 oil. i tried locating it this morning but cant find it... it is out there though.

i agree that using synthetic in these engines probably wont hurt anything & all kinds of peopel use it, but toyota specified conventional oil for some engine & synthetic for others.

184k on my 03' v6 been using Castrol edge high mileage conventional oil every 3-4k since I bought it with 143k

I’m about to do the first oil change on my new (to me) 09. Planning to use tried and true Mobile 1 high mileage.

‘06 w/151k. Valvoline high mileage conventional 5/30 every 5-7k since 78k when I got her 5 years ago.

03' V8 with 260k. Pennzoil Ultra Platinum Full Synthetic 5W30. Oil change every 5-7k miles.

No issues!