FUEL QUESTION

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I just recently purchased a Subaru Impreza RS. The question is which is the best type to use? Do I use just 87 octane regular or does it require premium gas? Thank you
 
The manual or your dealer is the definitive source for that info. "best gas" is an endless religious war on the interwebs.
 
IME the general view is that 87 will be just fine. many say going higher is a waste of money. my approach is go middle of the road and I use 89. but as I said...which octane gas is a religious war...similar to best oil to use.
 
The higher the octane rating the harder it is for the fuel to ignite and burn.
Unless your engine has a very high compression rating or you have forced induction in either a super charger or turbo charger system, you don't need, nor is it worth your while to pay for a higher octane fuel, when if anything it could do more harm than good. Incomplete combustion is not good for the longivity of your engine.
 
The higher the octane rating the harder it is for the fuel to ignite and burn.
Unless your engine has a very high compression rating or you have forced induction in either a super charger or turbo charger system, you don't need, nor is it worth your while to pay for a higher octane fuel, when if anything it could do more harm than good. Incomplete combustion is not good for the longivity of your engine.

right...higher octane needs more compression to burn cleaner/fully. first I have heard it put that higher octane could do more harm than good...but I get the logic.
 
There is normally a sticker in the fuel filler door. Higher octane is generally a waste of money, as stated. Many put it in to "treat their car well" but it can actually cause issues. For one, higher octane goes bad faster, and in a world where we're already forced to burn corn instead of fuel (ethanol fuel starts to go bad 2 weeks in; we have all kinds of problems with this on carbureted vehicles)

Save the money by buying what your car is built to run, and invest the money instead. :)
 
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Thank y’all for the reply’s. I am going for a drive out to the beach tomorrow. Only about 50 miles but I wanted to check in here.
 
Also worth noting that using higher octane than is called for can leave a lot more deposits from the unburned fuel.
 

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