First I need to clarify that I know almost nothing about vehicle mechanics. I also need to establish that I traded my 2019 Raptor for a 2023 Lariat for the added towing capacity. However I still own a 2021 37. Last night I was at a Christmas Party and met a person whom works at Ford Performance. I forgot his title, but he is fairly high up in the food chain. During a conversation he told me the Lariat has the exact same engine as the Raptor, but it is tuned differently. Then somehow we got on the conversation about octane. He said and I have since verified that both the Lariat and Raptor require 91 octane. I pointed out that the owners manual for the Lariat indicates it can take 87 octane. He told me can and should are two different things. He said “can” is a marketing strategy to imply if 91 is not available, 87 will work. He also said if I use 87 on a regular basis, it could melt some type of seals, (forgot the type of seal) which would not be covered under warranty. The way I recall the the conversation, he said all turbos require 91 and manufacturers are, or have moved to turbos to meet federal standards for mileage. He also said it will be almost impossible to find a new 8 cylinder in a couple of years. I believe (3 martinis down) he told me soon almost every new vehicle, minus a hybrid, will require 91 octane.