def1

iTrader: (6)

I just wanted to share my experience with switching from 91 octane to 93 octane.

Ever since I first got the car Ive only been able to put 91 octane in it. At first I would just fill up with whatever gas station was closest around whenever a fill up was needed. I "thought" the car was running good and fine until I did some datalogging with streetvision. I was getting a lot of counts of knock while running boost. So I started filling up with shell 91 octane and chevron 91 octane only. Went back to datalog again and on 4 back to back 3rd gear pulls if I remember correctly two or three of those pulls i was getting no knock. So that was a pretty big difference just from switching to a better brand of gasoline.

So for about 2 weeks I have been filling up with nothing but shell 91 and rarely get any knock and I can feel a driving difference as well. Then someone told me about this gas station a little out of the way that sells 93. So I waited til I needed to fill up and today I went out to buy some. The gas station is a little out of the way like I said before; about 5 miles out of the way but theres pretty much no lights to get there from my house and the speed limit is 60 mph. I drove around for a bit without boosting to see if there was any low rpm difference, which if there is I certainly could not tell. When I found some pretty open roads I let loose and went crazy haha.

I dont know if this was in my head or not but the exhaust note seemed quite beefier and smooth. The cars performance was definitely improved as well. The car pulled harder and the torque seemed consistent across most of the high rpm range. While the car did perform better I was noticing my boost had dropped from its usual 17-18 psi to 16-17 psi across each gear. I dont know if it had anything to do with gas or not just an observation. I was still getting certain rare knock like i also previously had on shell 91, but it may be due to the fact i still have some shell 91 mixed in with the 93 I just put in. Overall whenever I need to fill up though I will definitely be going to that gas station for some 93 oct. It was pretty cheap as well only $3.97

Methodical4u

iTrader: (9)

3.69 for 93 here

dethrock

Here we pay $1.31 a liter. So that would be $4.84 a gallon.... for 89 octane. We're getting f'd in the a.

I'm not sure what 93 is here. A guy I work with fills up his Skyline with it but he's gone for the day so I can't ask him. There's also only 1 gas station here that sells it.

bluebanana23

iTrader: (26)

I didn't know you could get 91 in texas.

Evoluvin

iTrader: (5)

where the hell in MD do you live???/
4.00 for 93 here

tdizzle06

I live in CA so the highest we have is 91, so thats all I used for the longest time. I finally found a station that has 93 and 100 though so I put 93 in and havnt stopped since. Makes a difference. Not a huge one, but enough that it is worth the trip even if it is out of the way a little.

4 bucks for 93....stupid bay area, highest prices in the US. 91 is 4.90, saw it over 5.50 when gas was at its worst a few months ago. Im paying 6 for 93. Cheapest 100 oct was about 7, seen it around 8/gal.



91 to 93 made a noticeable difference, I tried filling it up with 100 just for kicks but no different from 93. But on a stock car 91->93 is worth it.

EvolNinja

iTrader: (22)

Time to get a Scooter for DD when gas price hits $6/gal

Davethewave

iTrader: (9)

+1

596736

iTrader: (15)

Thats got to be no name gas cash only

CaliMR

iTrader: (1)

What part of the bay? If you are in the peninsula, the 76 on Woodside Rd. a couple miles east of 280 has 100 octane and IIRC it was $6.50 or so when I picked some up a couple weeks ago to play with after getting tuned.

If you are near Sonoma, just get it at Sears Point

tdizzle06

Ive filled up at that station before actually, I live just a little south of redwood city in mountain view, but it was more than that. I guess I got it on a bad day. Luckily my evo isnt my DD so its not too bad, its still a lot though especially with 200 miles to a tank

getcha

iTrader: (4)

4.30 - 4.51 for 93 here

I dont even look at how many gallons I buy, I just take the receipt and put it away.

CaliMR

iTrader: (1)

Where are you getting 93 and 100 then? I know there is a place in San Jose but I have not been there. Dagmar's or something like that. You could always try the old mothballs in the can trick and make it yourself



DISCLAIMER for any noobs that happen upon this thread: do not use mothballs. Not all mothballs have the right chemicals, and it only helps if the gas is really low octane, and it might make the can explode.


Oh and, sorry about the thread jack

tdizzle06

I get it at a station right near my house actually, VP Gas Station in Los Altos. Heres the address if youre close:

VP Gas Station
Los Altos Rancho Shopping center
660 Fremont Ave
Los Altos, CA 94024

The location of this station may be one of the reasons its so expensive though, everything in Los Altos is. Last time I was there which was about a month ago 93 was 5.90 something and 100 was 7.90 something

spdracerut

iTrader: (2)

You're probably seeing less boost because less is required to hit the same 'target load' due to the increased timing allowed by the higher octane. Uh, basically, you're making the same power at less boost because you have more timing (allowed by the higher octane).

On my car, I datalogged 91 vs a mix of 91/100 (bringing it to about 93-94octane). For one, I'm able to run 6 degrees more timing at 7k rpms with 93/94 octane vs. 91. According to the dyno plot from Evoscan, i'm making about 20-25whp more and it holds better past 7k rpms too.

Cali gas sucks *****.