Hello,
I do not recommend it for most vehicles that require premium fuel. However, here is an example of when I recommend using regular for a premium fuel vehicle:
Ford V8 engines were fit into Jaguar luxury sedans without any sort of retrofitting except for the engine cover.
These Jaguars were recommended for premium fuel, while the Mustang GT, Expedition, etc, were recommended to use regular 87 octane. To me, that does not add up, and I would never put premium into an engine that is recommended for regular.
Here is why most engines that call for premium fuel need it (and why I put it in my wife's ML-class):
Engines engineered for excellent performance (like the engines in BMW, Mercedes, top end sports cars, etc) are designed on the basis that, on a molecular level, the best performance will come from a fuel with the highest potential energy, which is the octane rating.
Since the engine is designed to run with a more volatile fuel, the amount of air brought into the engine will be of a greater quantity, and the engine would not run as efficiently without sufficient fuel quality.
This would mean a less efficient burn, more carbon build-up, and less power.
Also, I look at it like this: unless the person writing the article is citing an engineer with as much experience as the team who built the vehicle, I say he/she is outwitted.
