My car runs on premium but it has way more power than I ever use. Is there any way to change the tuning to run on regular gas and save a couple bucks? (2014 Porsche Cayenne 4.8L)
No.
If you wanted to save money on gas, you bought a wrong car.
If the car calls for premium use premium. Using a lower octane can cause pinging/pre detonation. Want less power get a different car or be easier on the throttle
Is there any way to .... save a couple bucks
don't drive a Porsche
Some places can professionally de-tune an engine, but at what cost? It's $200 plus the cost of the tuner to get a place like BAMA Performance to tune a car for you, if they can even do the Cayenne. They did a tune for my Mustang to take premium only. Truly, $20 extra for gas is chump change compared to what fixing things on that Porche costs, that's definitely not the brand of car to own if you're money conscious. You could buy a fixer upper house in Dayton, Ohio for the $65-$75k that SUV cost when it was brand new.
I don’t think so. I think that the problem is more cylinder geometry than ECU programming. You might be able to tune it to run a little leaner but that’s only going to lead to other problems. To really do it, you would have to rebuild the motor with different cams (which probably don’t exist; nobody is gonna make Porsche parts to get LESS power).
If you want to squeeze a little more MPG and you’re willing to give up performance, look at tires (and wheels). Put on a narrower tire with less rotating mass and you’ll get better fuel mileage.
