Originally Posted by billt460
Originally Posted by Corollaman
2016 fusion 2.0 ecoboost. The manual says 87 octane minimum but I''ve been using 91 or higher. How sensitive are these engines to lower octane fuels?
I would keep using what you have been, (91 or higher). I have never understood the logic of paying well into 4 digits more for a turbocharged, high performance engine, then turn right around and try to save a few bucks a fill up on cheaper, lower octane fuel.
Simple. It's not a "high performance engine", it's throwing a turbocharger on a low performance engine to make it viable, to get better fuel economy (if you're driving it like grandma), to meet EPA numbers. EPA has their own reasons but it's marketed to the consumer as paying less for fuel, which is what buying lower octane does too (obviously).
Better question is, who in their right mind buys a Fusion and thinks the goal is pretend it's a sports car for use on public roads? Makes no sense.
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It's the same with the 5.7 Chrysler HEMI. Yes, they'll run OK on 87. But you will not get the best performance or fuel mileage on that low octane fuel.
Maybe the same, if (again) the vehicle is treated like a sports car, but for trucks doing work, it's not the same because there is additional work being asked of the engine to haul a load.
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I use nothing but 91 octane in mine. It delivers great mileage and performance as a result. Today you can get away with using cheap gas in a lot of these cars, because the vehicles on board computer will automatically detune most all of these engines and prevent harm. But at the same time it prevents the engine from performing to it's maximum...... Which is what you paid extra for in the first place.
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It's absurd logic. There are hundreds of places to save money today. This should not be one of them.
Yes it's absurd, to pretend people should pay extra for their domestic sedan to floor it (else the performance difference was zero because neither was maxed out yet) to get from one stop light to the next slightly faster, putting more stress on the already stressed little 2L turbo engine and lighter duty tranny (also to improve fuel economy by reducing drag and adding complexity with more gears), and trashing their CV axles, tires, etc.
If you want a sports car, buy one. If it needs higher octane fuel it will be stated in the owner's manual.
On the other hand, it does make sense to go higher octane if you live in an unusual market where the cost difference is less than the slightly higher fuel economy using it.