I get the generalisation you're going for, but I think it's important for a bit of pedantry here.
To date, there's been precisely one 16 cylinder Vision Gran Turismo, which was a precursor to the Chiron, which is a 16 cylinder in the real world, and only had marginally overstated power in the game.
A quick skim through the selection of VGT's and I reckon the most common is 6 cylinder (split between various configurations) or perhaps V8s... and this is why I'm being pedantic. Pretty much all of the manufacturers elected to use a powerplant representative of what they do... BMW Inline 6, AMG V8 Bi-Turbo, Mazda Rotary, Suzuki 'Busa, Daihatsu with a 660cc, Subaru with a Flat 4, Lambo and Aston with V12s, Dodge going with a V10, Nissan have a V6TT, VW using a VR engine, Mini and Mitsubishi with I4's, Hyundai with a fuel cell, Peugeot with the engine from the Pikes Peak car, Zagato stating they virtually sourced a Callaway tuned V8.. etc. etc. They could have all just cheesed it with V16 or some such, but none of them really did (okay, again the 2X is the exception, but I think the reason why Chevvy went with a Chaparral was because they wanted to do something properly 'experimental').
... my point being that to make a generalisation like that - same as the 'spaceship' label - seems to avoid acknowledging some of thought that went into it from the manufacturers.