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#1
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gasoline
so i was wondering, why do our cars need premium? if i use a lower grade will it effect anything? can i potentially damage something? does the gas mileage change? (i cant experiment, my speedo doesnt work, so neither does any other mileage counter). what exactly is the difference?
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#2
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i think 91 octane is the minimum but i run 89 all the time and it runs great. sometimes if you run 87 or so you will get knock from the motor unless you have the ecu chip switched for 87 to prevent knock and you car will run like utter crap!!!unless you have the chip
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Seth 94' Barcelona Red w/ Tricoat black 2-tone AWD Ls -Sold Mods:AWD conversion/4.44 swap by Budfreak, Custom red interior lights, Custom Satin black dash, Power mode switch, Cold air intake, Permecool tranny filter,Sony xplode 10" sub, Sony xplode 1000w amp, Blitz in-line driver, DDM Tuning 6000k HID's, New paint job/body work by me, 97' Grill, QC shift kit, 17'' MB Motoring rims, 15&20 min mod, front & rear urethane swaybar bushings, Custom fiberglass sub box, Custom red led a/c control unit, perrin lightweight crank pulley, Black wrinkle finish powdercoated intake manifold w/ clear hoses , 02' outback heated/power black leather seats Soon to come:Fiberglass hood, upholster ALL suede to black leather Past subies: 92' Pearl White/black top LS-L-SOLD 96' Legacy Outback-TOTALED 99' Legacy Outback Limited 30th anniversary edition-TOTALED 98' Forester L -Totaled Other toys: 99' Forester S -WRX brake upgrade, soon an 04 wrx motor swap 06' B9 Tribeca-Stock 1982' Yamaha xj650 Maxim Mods: work in progress |
#3
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The EG33 runs a 10:1 compression ratio, which is fairly high. This makes it prone to knock, or detonation, the explosive burning of fuel in the cylinders. Knock turns engines into molten hunks of metal. In fuel, octane is the component which governs knock resitance. So more octane = more resistant to knock.
Plus, with more octane you can run more timing advance (firing the spark plugs earlier for more power). The 87 octane switch in the ECUTune chip backs the timing down to a level that will not hurt the engine even on lower octane. Many people have used regular in their SVXii without causing harm, but if you're going to put your car in a situation where it will be pushed, or the engine will run very hot, high octane is essential.
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Chris 92 Ebony Mica LS-L "A Rolling Restoration": 223,250 KM - Sleeping 2007 STi 6MT, Stance GR+ coilovers, PWR Rad, JDM hood badge, svxfiles 6000K HIDs, JDM Clear Corners, $15/15 min mod, $20/20 min mod, Energy Swaybar Bushings, Hella Supertones horns, Gold STi BBS rims, Group A lightweight crank pulley, A/C system removed, Custom header-back exhaust, Hybrid carbon/metal rear sway bar, restored headlights with CCFL halos 2008 Subaru Legacy Spec B - Diamond Grey Metallic - Sold 2020 Ram 1500 Longhorn - Red Pearl |
#4
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put in teh cheap ass 85 octane; he won't know the difference.
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Kenneth 1997 Subaru SVX LSi "Svetlana" #185 of 640 - 09/1996 - Polo Green Pearl - 34k miles 1992 Subaru SVX LS-L "Everett" #8738 - 01/1992 - Ebony Pearl - 139k miles - 5MT shifty - Sold 07/31/2011 1992 Subaru SVX LS-L "Sven" #1599 - 05/1991 - Claret - 168k miles - Traded 05/11/2005 2023 Subaru Crosstrek Limited CVT - Crystal White Pearl - 2.8k miles 2021 Subaru Forester 2.5i Limited CVT - Horizon Blue Pearl - 17k miles 2023 Volkswagen Jetta S 6MT - Pure White - 2.6k miles 2020 Hyundai Ioniq Limited EV - Ceramic White - 30k miles |
#5
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My car's a girl.
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Chris 92 Ebony Mica LS-L "A Rolling Restoration": 223,250 KM - Sleeping 2007 STi 6MT, Stance GR+ coilovers, PWR Rad, JDM hood badge, svxfiles 6000K HIDs, JDM Clear Corners, $15/15 min mod, $20/20 min mod, Energy Swaybar Bushings, Hella Supertones horns, Gold STi BBS rims, Group A lightweight crank pulley, A/C system removed, Custom header-back exhaust, Hybrid carbon/metal rear sway bar, restored headlights with CCFL halos 2008 Subaru Legacy Spec B - Diamond Grey Metallic - Sold 2020 Ram 1500 Longhorn - Red Pearl |
#6
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Kenneth 1997 Subaru SVX LSi "Svetlana" #185 of 640 - 09/1996 - Polo Green Pearl - 34k miles 1992 Subaru SVX LS-L "Everett" #8738 - 01/1992 - Ebony Pearl - 139k miles - 5MT shifty - Sold 07/31/2011 1992 Subaru SVX LS-L "Sven" #1599 - 05/1991 - Claret - 168k miles - Traded 05/11/2005 2023 Subaru Crosstrek Limited CVT - Crystal White Pearl - 2.8k miles 2021 Subaru Forester 2.5i Limited CVT - Horizon Blue Pearl - 17k miles 2023 Volkswagen Jetta S 6MT - Pure White - 2.6k miles 2020 Hyundai Ioniq Limited EV - Ceramic White - 30k miles |
#7
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Quote:
Pay attention here. A lot of people will tell you to run regular, and while you will probably not destroy the engine running it, you will NOT be seeing the level off efficiency or performance that the SVX is capable of. Those who say that regular won't make a difference are mistaken, but I can't really blame them. The SVX is very sensitive to knock, and has a computer that is slow to learn. If you put regular gas in the computer will throttle back timing over time to compensate, causing a lack of millage and power, but keeping the engine healthy. Most people who put regular gas in their premium required cars won't notice a difference if they one day decide to fill it up with premum, as the driving cycles one tank typically allows will not be enough to allow the computer to learn to advance timing, it is something that happens on a gradient, and over time, so it isn't noticeable. That being said, if you got in shelfys car, drove it, then drove a car that had adapted to premium and had always run it, you COULD tell a difference, and a marked one at that. I estimate that shelfy is losing 10~20% in power and 10% in milage because of his blasphemous ways. The rule here is thus, Subaru's engineers knew what they were doing, and I would listen to them. They would not advertise the car as premium only if it worked out just as well to run regular, as cheaper fuel is always a good selling point. In closing, I would recommend that you look at both the "ignition timing" and "octane" entries in wikipedia and fully understand them if you want a real answer to your question. While 87 won't kill your car, it will cost more in the end due to lost efficiency. END OF LINE.
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Patrick 1995 Ebony Pearl. S.N. 0001 "Araby" JDM Power Mode Switch, Integrated GPS/Video Player 6Xk Miles. 1992 Teal - Sold to Mysvxrocks [SIGPIC][/SIGPIC] |
#8
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If you live in an area where premium is higher than 91 octane you can safely top-off with regular without worries. Running greater-than-specified octane gains you nothing.
dcb |
#9
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Burn Regular
The cars run fine on regular. As indicated by some that really know--you won't notice ANY difference in performance with regular. I have probably put as many miles on these cars as anyone here and it has all been on regular gas (86-89 octane).
The ONLY cautionary note is that if it ever does ping or run after key is turned off--THEN burn premium--or check for knock sensor problem codes. Lee
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SVXx2 92 SVX LS-L Silver 92 SVX LS-L Burgundy (structurally challenged with 2792 miles) 96 SVX LSi Red 92 SVX LS Pearl (Parts) 01 F150 4X4 Red (+6 with other members of the family) FREEDOM IS NOT FREE |
#10
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Quote:
Under normal driving conditions, I put in 94 exclusively at the shell on my way to work. Think about it this way: Cost difference between 87 and 92 is roughly 20 cents. On average, I put 12 gallons of gas in my car. That's $2.40 more per fill up, every 8-10 days. If your gonna own an SVX, you can't be cheap, because premium fuel is about the least expensive maintenance item. If you want your car to last, and treat you well, I recommend sticking with the manufacturer recommendations, they're not there for show, they're there to prolong the life of your car, and enhance your driving experience.
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*No SVX at the moment...* 1987 Winnebago Elandan 35' 2001 Yamaha Roadstar 1600 2004 Ford Excursion Eddie Bauer, 6.0litre Power Stroke Diesel - Daily Driver. Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well-preserved body, but rather to skid in sideways, scotch in one hand, body thoroughly used up, totally worn out and screaming HOOOOYA !!!!! |
#11
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Quote:
Just FYI i have never but anything but 93 in my car and get any where for 24-26 MPG city/highway mix.
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Amanda Kenny 1993 Subaru SVX Anniversary Edition Red #23 we dont do anything slow |
#12
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Funny how what fuel to use is one of the most provocative topics around here.
Of course Subaru specified "premium" for a reason, and the contention that lower octane diminishes economy and performance is perfectly sensible. That said, if my own findings with my own cars supported this, I'd immediately switch to the highest octane I could find. Fact is, I routinely alternate between pumping 1/4 and 3/4 tank of premium and regular, maintain meticulous fuel economy records and conclude that, as applies to my cars and my type of driving, there is no measurable difference. Buying more octane than necessary is a waste of money, in my book. dcb |
#13
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Three things:
1. Buying more octane than you need is a waste of money 2. Yes, the ECU will "learn" what you're feeding it, but it takes a while 3. Audible knock is a bad thing -Bill
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Retired NASA Rocket Scientist Most famous NASA "Child" - OSIRIS-REx delivered samples from asteroid BENNU to Earth in Sept. 2023 Center Network Member #989 '92 Fully caged, 5 speed, waiting for its fully built EG33 '92 "Test Mule", 4:44 Auto, JDM 4:44 Rear Diff with Mech LSD, Tuned headers, Full one-off suspension '92(?) Laguna, 6 spd and other stuff (still at OT's place) My Locker |
#14
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Later
Quote:
Lee
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SVXx2 92 SVX LS-L Silver 92 SVX LS-L Burgundy (structurally challenged with 2792 miles) 96 SVX LSi Red 92 SVX LS Pearl (Parts) 01 F150 4X4 Red (+6 with other members of the family) FREEDOM IS NOT FREE |
#15
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Quote:
Fact--they also detuned the cars from its potential. Of course they ALWAYS hedge their bets. Again--the car runs great on regular fuel. My findings after several hundred thousand miles in several different SVXi come up with the same findings you indicate--no difference--just cheaper. Lee
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SVXx2 92 SVX LS-L Silver 92 SVX LS-L Burgundy (structurally challenged with 2792 miles) 96 SVX LSi Red 92 SVX LS Pearl (Parts) 01 F150 4X4 Red (+6 with other members of the family) FREEDOM IS NOT FREE Last edited by lhopp77; 01-10-2008 at 03:48 PM. |
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