[Mac]

I wonder what percentage of persons with leased luxury cars that are tuned to run on ethyl decide to disregard the manual because they are not in it for the long term and don't have the same stake or pride of ownership in the car. Probably a lot, and there does not seem to be a lot of engine problems experienced by subsequent owners because of it, so I'd guess the car has the ability to save itself from the potential hazards of lower octane fuels.

JGCs, for instance, are designed to run on regular, just like a Hondas: they have lower compressions and putting a higher octane in them actually is a waste and can result in poorer performance.

I'm not an automotive expert, but for towing, mountain driving or driving at altitudes, the results of flaunting the manual's recommendations probably will noticed much more than in easy driving situations. The ML is heavier than many cars and pushes a lot of wind and I'll probably own it for a while so the extra cost, to me, is part of the investment.

So far, at 65.5K, the engine doesn't burn a drop of synthetic between FSS intervals and I cannot take any credit for it other than giving the car an easy break in. It seems to me that using the proper fuel might also help keep the lubricants cleaner over time, which would be good for the life of the engine.