3.6R Much Better on 93?

I for some reason decided to fill up with 93 this tank. Car feels more powerful and is getting about 3mpg better so far.

Is this consistent with other people’s experience playing with 93 on a stock ‘13 3.6R? I almost always buy gas from the same station and the results on 87 have been consistent barring the weather.

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nope, car is not programmed to take advantage of higher octane... I have a 2010 3.6R and I have used nothing but 87 and the car is running as expected.

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nope, car is not programmed to take advantage of higher octane... I have a 2010 3.6R and I have used nothing but 87 and the car is running as expected.

Eh, I don’t know about that. It’s definitely programmed to run on a minimum of 87 and rated on 87, but depending on what exactly would be holding the motor back, it mightacould do better on higher octane gas. If the primary problem is it pulling ignition or cam timing out due to knock, higher octane gas absolutely would allow for higher output.

Of course, there’s also the possibility that something (carbon buildup?) could be causing some instability issues leading to knock, that might be making my engine run “normally” on 93 and less well on 87. You’d think I would have heard it ping if that was a problem, though.

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It's also fairly common knowledge subaru runs a pretty aggressive timing advance. That could account for a slight uptick in performance and fuel mileage.

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you guys waste your money if you want...but Subaru never said use higher octane to get better performance... Honda did.. for the 2003-7 accord.. j series v6 all you got was maybe 15 hp...

does my car run smooth? yes, does it idle smooth? yes. does it respond well to the throttle? yes. does it ping? no. do I get better than advertised gas mileage? yes

no reason for wasting money on more expensive gas...

The 3.6R is tuned very lean from the factory to make use of 87 and meet gas mileage figures. The engine thrives on 93 and you will feel a difference with 93 in both performance and mileage. 93 is actually better for this engines longevity in the long run.

A tune made for 93 octane can gain you nearly 30 hp over stock, but in fairness warning you will lose a bit of mpg on a power tune, but man is it fun.

^ what do you consider longevity? I am at 142K and climbing...

want engine longevity? don't beat the pee out of it and service it regularly.

The 3.6R is tuned very lean from the factory to make use of 87 and meet gas mileage figures. The engine thrives on 93 and you will feel a difference with 93 in both performance and mileage. 93 is actually better for this engines longevity in the long run.

 

A tune made for 93 octane can gain you nearly 30 hp over stock, but in fairness warning you will lose a bit of mpg on a power tune, but man is it fun.

Just for fun I might have to log timing advance and cam phasing — if that can be done with FreeSSM, anyway — to see what kind of a difference 93 makes over 87.

As for getting a tune, I may consider it one day, but $500 at least plus $200 for the cable is a fair bit more than I want to spend on the car that’s supposed to be my reliable daily while my fun car’s holed up in the garage.

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The motor will be happier on 93, but honestly it won't matter. 93 once in awhile cleans out the car.

And I have a tune on my daily, its been tuned for over 70k miles on my h6 and shes never had one problem. (Im at 151k now)

how does the 93 octane "clean out the car"?

For some vendors, the additive package for the lowest grade differs from the upper (detergents, etc.) but as long as you buy the mid-grade gas, there really isn't any benefit to going beyond that. It's not a high compression engine (10.5:1) so the added detonation resistance doesn't buy you anything.

how does the 93 octane "clean out the car"?

 

 

For some vendors, the additive package for the lowest grade differs from the upper (detergents, etc.) but as long as you buy the mid-grade gas, there really isn't any benefit to going beyond that. It's not a high compression engine (10.5:1) so the added detonation resistance doesn't buy you anything.

Gasoline companies used to add cleaners to fuel to only the high octane (mid octane is usually a mix of regular and premium), but law makers have changed that (I think that happened at the federal level). The cleaners should the same for all grades of gasoline unless the cleaner is how they are increasing the octane.

Gasoline companies used to add cleaners to fuel to only the high octane (mid octane is usually a mix of regular and premium), but law makers have changed that (I think that happened at the federal level). The cleaners should the same for all grades of gasoline unless the cleaner is how they are increasing the octane.

That would be one of the defining characteristics of top tier gasoline - but not all stations are top tier - some geographic locations are better than others, but in Albuquerque, anyway, there seem to be a ton of "speedway" stations, which are not top tier rated, as well as "alon" which is also not... (note - that doesn't mean they have bad gas - they very well might have the same detergents, etc. as the premium does in all of their grades)

That would be one of the defining characteristics of top tier gasoline - but not all stations are top tier - some geographic locations are better than others, but in Albuquerque, anyway, there seem to be a ton of "speedway" stations, which are not top tier rated, as well as "alon" which is also not... (note - that doesn't mean they have bad gas - they very well might have the same detergents, etc. as the premium does in all of their grades)

I go to Sunoco here in Mass. There is another gas station near me that is probably the cheapest around, but their 87 octane seems to be horrible. I used it in my pickup truck when I had it, and my truck would sometimes take a bit to start up. I then went to Sunoco, and bam the problem was gone. Now fast foward to when my mother gave me her Legacy, I tried the same thing. Got the same result, went from the cheap place to Sunoco and I've had no issues ever since. My mother's 2018 Infiniti QX30 Premium does use 91/93, and we do go to the cheapest gas station nearby, and the higher octane gas at that place works fine. This is why I think that maybe it's worth the extra 5 or 10 cents (in my case for 87 Octane) to get some good trustworthy gas from a known gas station. I know for sure that if I had a Shell gas station near me, I'd probably go there.