Later Toyotas cannot use Mobil 1 oil?

My long trusted technician told me today that later Toyota vehicles can not be
served with Mobil 1 synthetic oil due to Toyota has their formula on their own
oil. He did not say what models involved but just define later models as after 2007.
I asked him what would happen if I use Mobile 1 on my 2012 Yaris, he said Mobile
1 would affect the idle setting and might void Toyota warranty.
I am very shocked to learn his advise but he is a super good technician, especially
on Japanese cars, anybody heard the Mobile 1 vs Toyota cars story? Thanks!
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Comments
The owner's manual says, for engine oil type: "Toyota Genuine Motor Oil or equivalent
Oil grade: ILSAC multigrade engine oil. Recommended oil viscosity: SAE 5W-20". If you don't have an owner's manual, you can look this stuff up at Toyota.com under the Owner's section.
Note the "or equivalent" language. I don't see anything about a "compliant" requirement or any prohibition against using a synthetic oil.
Wikipedia says "Engine oils bearing the API starburst symbol since 2005 are ILSAC GF-4 compliant."
Thank you Steve, the motor oil cap says 5W-30 so I think the Mobil 1 5W-30 should work well,
still don't understand why my tech warmed me so seriously today.....
Your mechanic probably went through the "sludge wars" about 7 or 8 years ago and doesn't trust anything but the Toyota brand now. Although with all the gel issues back then, you'd think your mechanic would be more inclined to use a synthetic.