TheIndianGuy

Hello:

I have a 2014 X GSR completely stock with about 700 miles.

I recently filled it up with 93 octane but I believe it wasn't 93. I filled it up from a private Exxon and think it was 91. Ever since I filled up the car seems to be running weird and has been idling rougher than usual. I did push the car a little to like 5k rpm but didn't go all out WOT. When doing that the car felt sluggish and didn't perform like it should.

My question is would the 91 effect the car at all as far as damaging the engine?

I have about a half of tank left should I fill it up with 93 octane or wait till I burn the remaining gas off ?

I tried searching for something on that topic but didn't find anything.

Thanks for the advice.

Sev

iTrader: (10)

Here in CA all we get is **** 91.

wkarl

iTrader: (1)

The stock tune is set up for 91 octane, so no you shouldn't have any issues with it. There are a lot of places in the country where people don't even have the luxury of 93. If you're down to half a tank, fill it with 93 from a different station and see how it runs. Its likely you might've just gotten some bad fuel. Even if you had accidentally put 89 in it, you could run it all the way through a whole tank that way and if you didn't go into boost and babied the car, you'd never have a problem.

schow001

+1 on babying the car if you really think you put 89 in your tank until you burn through it and refill at another gas station.

TheIndianGuy

So I put some Octane booster and all is well, car is driving 100% better. I will now just burn whatever gas is left and fill it up with actual 93 octane this time.

Thanks for all the info.

mrwickd123

The stock tune is in fact set up for minimum of 93. Here's my source (the manual):

TheIndianGuy

Yup I read that and that's why I got scared. But like I said earlier the octane booster helped.

MikePL

iTrader: (9)

I was under the impression that a stock tuned evo came with a "low octane map" for something like this, or if you were in an area where only 91 or lower octane gasoline is available. However, with your symptoms of knocking and what not, could have just been really really bad gas.


On a side note, I personally always look back at the gas attendant when they pick the octane rating. I have made a habit out of it just in case. I usually pump myself but some places in Jersey won't let you.




Edit: Just noticed you are also from Jersey. Unless you are on the parkway you can pretty much pump it yourself. I always go to the same gas station and the attendant knows me and always gently places things to make sure he doesn't scratch my car etc, and he's the only one I let pump without a worry, but I still watch him pick the octane.

Iowa999

iTrader: (1)

Buy a lottery ticket with the money next time. In both cases, it's generally a waste, but there's a small chance the ticket will pay off.

If you insist on adding "octane boosters," just get some toluene from a hardware store. Same thing, only a tenth of the price. Off-road only, of course, as you didn't pay road-use tax.

ddawg1130

iTrader: (1)

OMG, read past the first sentence and the manual even CLEARLY SAYS the stock tune can handle 91 octane just fine.

Per the manual, does it provided "optimum performance"? No. But it clearly is saying it can be run just fine without issues.

g'd out

iTrader: (1)

Manual also states u can run lower octane gas just don't do it for a long period of time. 1-2 times then switch to 93 as soon as possible.

nerdbotSKRA

iTrader: (4)

In case premium unleaded gasoline 93 is not available, unleaded gasoline rating of 91 can be used... looks like 93 is the minimum requirement for optimum performance.

If Mitsu sold the car under the assumption premium gas was 93 octane everywhere, well. It's getting too late for me to continue that thought.

--

I've ran 91, 92, and 94 in my car on the stock map, 91 definitely gives that "decreased performance" mentioned in the manual. Didn't really notice too much of a difference between running 92 and 94 except for the rate it burned off (completely different with appropriated AP flashes though, of course). The 92/94 are both up to 10% ethanol.

I usually run the 92 without any hiccups, that's the midgrade from Husky around here (at 2/3 locations anyway), can usually score it for the same price as 91 at Shell or Petro-Can, may as well.

wkarl

iTrader: (1)

I see several people have already come to my rescue on this, but I'll clarify anyway. I really shouldn't have phrased that like, "The stock tune is set up for 91..." I should have said "The stock tune can handle 91..."

Exactly, ^this^ is just it. Stock evos are very dialed in compared to what the DSMs and some other cars are from the factory, but the tune isn't so sensitive that the engine is in danger of grenading if 93 octane isn't used. If that were the case we would be seeing a lot more catastrophic failures in stock evos because I can guarantee you not everyone out there is putting 93 octane in their car.

spatel133

you will be fine.
just dont get onto the car until you burn through the tank or two. typically ~400 miles to be on the safe side. ive done it when i could only fill up at WAWA which only carrys 92 octane. i know its hard but doesnt matter on stock car as long as you dont getonto the car.

Alpha X

iTrader: (9)

Driving across the country in my Evo the highest they had somewhere in New Mexico was 89 octane.

I drove it till I had to fill up again and the only thing that happened was the SES light coming on.

After that I put in some 91 octane and it went away.