|
The Boxster has a very high compression ratio for its age, high enough that it retards timing when the clutch is disengaged because the sudden rev drop could cause knock. I wouldn't play with lowering the octane on that. With all the quirks the M96 already has, why mess with pre-detonation?
The 986 has an 11.0:1 compression ratio, the same as a Ferrari 360 Modena and a Lamborghini Murcielago.
Many cars that "recommend" 91+octane are just hot versions of economy cars, with compression between 8-10:1 and the rest of the difference made up by timing or boost. With electronic spark control, the car can easily back off timing if fed regular fuel, and run like a base model. Some non-sports luxury cars might only call for premium to keep the engine clean, after all being stranded in the middle of nowhere because you can't find 93-octane isn't a very luxurious experience.
But the Boxster and the M96 are both designed from the ground up for performance, it's not an up-tuned version of an engine that runs on 87 and certainly not designed to be low-maintenance.
Of course, I haven't tried running less-than-recommended fuel, but I have a strong inclination that you shouldn't try it, either.
|