|
BRZ First-Gen (2012+) -- General Topics All discussions about the first-gen Subaru BRZ coupe |
|
Thread Tools | Search this Thread |
12-25-2022, 05:38 PM | #1 |
Senior Member
Join Date: Jul 2016
Drives: 16 Silver BRZ, 04 Silver WRX wagon
Location: Rockland county, NY
Posts: 1,411
Thanks: 182
Thanked 768 Times in 439 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
Thoughts on using 89 octane
So I mostly commute with my BRZ and lately rarely goose it over 3-4K. I have other cars to play with. So last time I got gas they did not have 93 and I out 89 in and the car felt exactly the same. No I did not log it to see if there was knock or anything funky going on. But if I did not know it was 89 I would never be able to tell for commuting. Thinking it would be great to do this and save some money burning gas on my long highway commute. Any thoughts? Is there and OFT OTS tune for 89?
|
12-26-2022, 12:12 AM | #2 |
Senior Member
Join Date: Jan 2017
Drives: brz 2017 hksv2
Location: italy
Posts: 2,196
Thanks: 500
Thanked 1,067 Times in 775 Posts
Mentioned: 65 Post(s)
Tagged: 0 Thread(s)
|
take a ots tune for 91oct and open timing B map and reduce the timing, like -1/-2 degrees from 2k to redline
should be ok will consume a little bit more fuel than usual, nothing extraordinary thought |
12-26-2022, 08:19 AM | #3 |
Senior Member
Join Date: Sep 2020
Drives: FR-S
Location: USA
Posts: 171
Thanks: 313
Thanked 70 Times in 50 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
|
Any Costco gas stations in your area? The price of Costco 91 for me is basically the same as 89 at other pumps (or even less).
|
12-26-2022, 11:52 AM | #4 |
Geo Tyrebighter Esq
Join Date: Mar 2013
Drives: '13 scion fr-s
Location: pnw
Posts: 4,185
Thanks: 6,318
Thanked 4,981 Times in 2,197 Posts
Mentioned: 39 Post(s)
Tagged: 1 Thread(s)
|
Friends don't let friends RB
oh, wait
__________________
--
"I gotta rock." -- Charley Brown |
The Following User Says Thank You to bcj For This Useful Post: | x808drifter (12-30-2022) |
12-26-2022, 02:59 PM | #5 | |
Senior Member
Join Date: Jan 2018
Drives: Crapcan
Location: Oregon
Posts: 11,162
Thanks: 18,155
Thanked 16,322 Times in 7,380 Posts
Mentioned: 107 Post(s)
Tagged: 0 Thread(s)
|
Quote:
__________________
"Experience is the hardest kind of teacher. It gives you the test first and the lesson afterward." -Oscar Wilde.
|
|
12-26-2022, 04:10 PM | #6 |
Senior Member
Join Date: Mar 2017
Drives: JRSC BRZ SOLD
Location: Ohio
Posts: 934
Thanks: 676
Thanked 739 Times in 396 Posts
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
|
What’s the $ spread on 89 to 93 or even 91 in your area? It’s maybe $.30 here or < $7 for a fill up. For $7 I’d just find a station with at least 91oct. These cars are knock sensitive enough without running the wrong gas long term.
|
The Following User Says Thank You to PulsarBeeerz For This Useful Post: | Tatsu333 (12-26-2022) |
12-27-2022, 10:39 AM | #7 | |
Member
Join Date: Apr 2014
Drives: 2014 Subaru BRZ Premium
Location: Chicago
Posts: 14
Thanks: 6
Thanked 16 Times in 7 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Quote:
For example: the base table says to run 10 degrees of ignition advance and the advance table is an additional 5 degrees. So the engine will be running anywhere from 10 to 15 degrees of advance depending on how much knock it sees. When using lower octane fuel my guess is that you will be seeing more knock and therefore be running less ignition advance which ultimately means less torque. It's possible that the octane could be low enough that you are running only the base table (0% of advance table) and the engine is still knocking because it has no more room to retard the timing further. This is probably unlikely but would have to be verified with data logging. How will this affect your engine long term? I couldn't tell you, but maybe this was still helpful... |
|
The Following 2 Users Say Thank You to Plastic Robot For This Useful Post: | Ernest72 (12-27-2022), Ohio Enthusiast (12-27-2022) |
12-27-2022, 10:41 AM | #8 |
Senior Member
Join Date: Jul 2016
Drives: 16 Silver BRZ, 04 Silver WRX wagon
Location: Rockland county, NY
Posts: 1,411
Thanks: 182
Thanked 768 Times in 439 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
Guess I will stick with 93, currently running a Wayne rom tune for 93. Data logged last summer without any knock. Maybe I will try 91 and datalog. My thought was that since the rpm’s rarely get above 4k in a highway commute that the ECU could easily compensate for lower octane. I need this car to last as my commuter, so better to be safe or prove it works.
|
12-27-2022, 11:04 AM | #9 | |
Senior Member
Join Date: Apr 2020
Drives: 2018 BRZ
Location: Dayton, OH
Posts: 898
Thanks: 1,367
Thanked 764 Times in 433 Posts
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
|
Quote:
|
|
12-27-2022, 03:03 PM | #10 | |
Member
Join Date: Apr 2014
Drives: 2014 Subaru BRZ Premium
Location: Chicago
Posts: 14
Thanks: 6
Thanked 16 Times in 7 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Quote:
My guess is that there's enough margin in the base ignition table to deal with the lowest octane fuel out there and this would probably never happen. Would be interesting to see some back to back testing comparing octane readings to see how much timing is getting pulled. |
|
01-04-2023, 07:19 PM | #11 |
Banned
Join Date: Sep 2019
Drives: Red 2019 Subaru BRZ
Location: Vancouver Island Canada
Posts: 107
Thanks: 9
Thanked 65 Times in 30 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
Really. Mine has only had Chevron Good Ole Premium 94 octane, its entire life. Well there was 89 octane crap in it when I bought it new, but that is the only alcohol my baby has ever seen.
Its for sale on Vancouver Island. It has 17,200 Km on it and is cherry, and red too. I'm trading it for a Solterra in a few weeks, so be quick. |
01-05-2023, 07:03 AM | #12 |
Be Kind
Join Date: Apr 2020
Drives: 2020 86
Location: MD
Posts: 1,078
Thanks: 5,162
Thanked 1,254 Times in 605 Posts
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
|
Weird. It's .65-.70 between 87 and 93 here in MD.
__________________
|
01-05-2023, 09:53 AM | #13 |
Senior Member
Join Date: Jan 2014
Drives: FR-S,GTI
Location: Cocoa, Florida
Posts: 1,155
Thanks: 228
Thanked 823 Times in 419 Posts
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
|
Here in Touristland the difference is about .40-.50 cents between 89 and 93. But gas is .40-.50 cents less at discount stores like Costco, Sam's or BJ's. I only use BJ's 93 octane because it's usually cheaper than regular anywhere else.
|
01-05-2023, 09:57 AM | #14 |
The Dictater
Join Date: Apr 2017
Drives: '13 Red Scion FRS
Location: MD, USA
Posts: 9,432
Thanks: 26,115
Thanked 12,433 Times in 6,148 Posts
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
|
Or more. I've seen it as high as $0.90/gal difference.
__________________
If a picture is worth a thousand words, a model is worth ten thousand pictures.
Also: "Build Thread" |
The Following User Says Thank You to Spuds For This Useful Post: | Wally86 (01-05-2023) |
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
mixing e85 (109 octane) with e15 (91 octane) | pcguru2000 | Engine, Exhaust, Transmission | 19 | 03-08-2022 10:35 PM |
Do you use 93% octane | RichardsFRS | Mechanical Maintenance (Oil, Fluids, Break-In, Servicing) | 62 | 02-08-2016 11:21 PM |
91 vs 94 Octane | nocwage | Engine, Exhaust, Transmission | 27 | 07-15-2014 12:52 AM |
100 octane race gas: 91 octane ratio? | GhostofAkina | Scion FR-S / Toyota 86 GT86 General Forum | 15 | 02-08-2013 01:23 AM |
93 Octane? | ashtray | BRZ First-Gen (2012+) -- General Topics | 175 | 04-04-2012 12:22 PM |