Ojala wrote:
Just not all at the same time. Just sayin.
I can only speak for a specific case with Subarus in regards to engine durability. My main issue with the stock Subaru is the CL/OL transition delay. Just from my own experience the delay caused my motor to be leaner than I like at max throttle opening which can lead to knock. As far as power and mpg I prefer to emphasize power, but I did increase timing at part throttle/low load so that does help mpg as long as I keep my foot off.
If subaru's lean out at WOT, then there's a problem.
But most cars are calibrated to protect the engine so that it will make the maximum power AND be able to for well over 120k (which is the emissions rules). FE should be dependant on physics and gear ratios, but if someone is leaning out the cal to get FE, then I'm quite certain that it sacrifices emissions badly, and probably durability.
Turbos are a bitch- have to account for a whole slew of exhaust temps (exhaust valves, manifolds, and turbos- maybe sensors and catalysts) and turbine speeds. Add in DI, and real fuel, and there are a lot of things that are done to make sure the car survives in the real world.
My observations of aftermarket hacks, I mean "tunes", are that they violate a slew of the requirements all at once for the name of power. And when the car fails, the owners expect the OEM to replace the damaged parts, when the damage is due to the modifications that the owner makes.