93 Octane?

[tranzformer]

Originally Posted by Want.FR-S

Yes indeed, but that 89 AKI is never called a *premium* fuel in any region, right?

Right. Usually referred to "mid-grade" and basically a mix of regular and premium fuel (gets mixed underground as most gas stations have 2 underground tanks).

[Want.FR-S]

Originally Posted by tranzformer

Right. Usually referred to "mid-grade" and basically a mix of regular and premium fuel (gets mixed underground as most gas stations have 2 underground tanks).

Offtopic: I remember one time one gas station ran out of regular so they block off both regular and mid grade and set the price of premium with regular price. That free premium ran for about two days until the fuel truck came with regular.

[Allch Chcar]

Originally Posted by Want.FR-S

Offtopic: I remember one time one gas station ran out of regular so they block off both regular and mid grade and set the price of premium with regular price. That free premium ran for about two days until the fuel truck came with regular.

Also Off-topic: Premium gas sales are only like 10-15%(edit) of all Gasoline in the US. I've heard stories of stations switching out Premium to E85 and getting more sales!

Ontopic:
We should stop using AKI and switch to using the RON like everybody else. Then we wouldn't have these problems. A grassroots effort might do it.

[serialk11r]

1%??? Are you serious? Does that mean most luxury car buyers...are filling their "PREMIUM UNLEADED FUEL ONLY" cars with regular?

I'd be up for more E85 stations around here at least, ethanol+direct injection is a pretty awesome combo

[Allch Chcar]

I double checked since I was going off memory but it seems I did forget a 0. It was 10% a couple years ago during the recession, 15% around 2000, I managed to find some numbers that said it was almost 30% in 1989!

[Dave-ROR]

I'm still going with the marketing intern in new jersey seeing "premium fuel required" and simply on verging that to "93 octane" because that is their premium. It's going to be 91 "required"/93 recommended.

[tranzformer]

Should note that the manual states this regarding the fuel:



The engine is designed to operate at maximum performance using unleaded gasoline with an octane rating of 93 AKI (98 RON) or higher. If 93 AKI (98 RON) fuel is not readily available in your area, unleaded gasoline with an octane rating of 91 AKI (95 RON) may be used with no detriment to engine durability or driveability. However, you may notice a slight decrease in maximum engine performance and you may hear some knocking (pinking) of an engine while using 91 AKI (95 RON) fuel. Use of 91 AKI (95 RON) fuel will not affect your warranty coverage.

[serialk11r]

Originally Posted by tranzformer

Should note that the manual states this regarding the fuel:
stuff


Where are you getting the part about knock? I see this:

■ Fuel types
Unleaded gasoline (93 AKI [Research Octane Number 98] or higher)
If unleaded gasoline with an octane rating of 93 AKI (98 RON) is not available, unleaded gasoline with an octane rating of 91 AKI (95 RON) may be
used with no detriment to engine durability or driveability.

Sounds like it's one of those things where you might get some knock with 91 under hot weather and heavy acceleration at low speeds.

[tranzformer]

Originally Posted by serialk11r

Where are you getting the part about knock? I see this:


Sounds like it's one of those things where you might get some knock with 91 under hot weather and heavy acceleration at low speeds.

Just from the owners manual. Section #6: Vehicle Specifications page 420

https://pictures.dealer.com/subaruof...1914b5d7f4.pdf

[serialk11r]

Ah okay yes, I found it too.

[tranzformer]

Originally Posted by serialk11r

Ah okay yes, I found it too.

Interesting that they state the knock will have "no detriment to engine durability or drivability." I thought a continuous knock could definitely affect durability and drivability.

[serialk11r]

Perhaps light knocking isn't too big of an issue (I wouldn't know), but I wonder what they mean by "driveability"...if I were driving and my engine made funny noises, I'd wonder what is going on even if there's no torque fluctuation.

[Allch Chcar]

From what little I know, and until one of the more knowledge guys correct me, sustained knock is what will kill a factory engine. So yes a little bit is okay, otherwise the knock sensor would be pointless.

[carbonBLUE]

Originally Posted by serialk11r

Perhaps light knocking isn't too big of an issue (I wouldn't know), but I wonder what they mean by "driveability"...if I were driving and my engine made funny noises, I'd wonder what is going on even if there's no torque fluctuation.

just read the manual, 93 is what they want in the engine 91 is acceptable anything lower will cause heavy knocking im


manual says use 91 as lowest octane rating

ohh yeah and dont use anything with more than 10% ethanol