"7:07" (fanbrain001)
04/24/2014 at 15:18 • Filed to: None
0
28|
"7:07" (fanbrain001)
04/24/2014 at 15:18 • Filed to: None | 0
| 28 |
I live in an area that offers 85 octane fuel. Naturally, it's the cheapest at the pump, so most people, including myself, have been purchasing it for years.
The elevation in my hometown is ~3,200 ft. Where I work is around 2,800 ft. and I make trips to visit family an hour North, up to 5,800 ft.
What is 85 octane doing to my car (a 1995 Geo Prizm, 1.6L, 5 speed)? I average 35MPG, so I can't think it's doing horrible things to my engine, but am I leaving power on the table, or worse, causing damage?
Have a woody:
For Sweden
> 7:07
04/24/2014 at 15:20 |
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What's the minimum octane rating on your car?
CalzoneGolem
> 7:07
04/24/2014 at 15:20 |
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Your Geo Prizm is perfectly fine. 85 Octane is not harming it slightly.
MonkeePuzzle
> 7:07
04/24/2014 at 15:21 |
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provide pic of Geo Prizm, also, 35mpg, woot woot. Also, probably nothin' bad is happening to your engine.
Mattbob
> 7:07
04/24/2014 at 15:21 |
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does the engine sound fine? If it isn't detonating, I wouldn't worry about it. You will get less power if the engine is retarding the timing so as to not detonate, but a '95 prizm, you are probably fine.
MIATAAAA
> 7:07
04/24/2014 at 15:24 |
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You're not doing it any harm. Any addition of power will be negligible.
RazoE
> 7:07
04/24/2014 at 15:25 |
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Put it this way. A higher octane is what, 10 cents more per gallon? Let's say you fill up with 10 gallons. You'll only spend $1 extra. Is $1 really going to break your bank? Think about how much it'd cost to fix something caused by shitty gas.
MontegoMan562 is a Capri RS Owner
> 7:07
04/24/2014 at 15:25 |
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probably fine, and we'll just be honest here, 95 prizm is happy it's a live, doesn't care what fuel it receives.
Jake - Has Bad Luck So You Don't Have To
> 7:07
04/24/2014 at 15:25 |
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mmm, that Buick though.
dogisbadob
> 7:07
04/24/2014 at 15:28 |
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It might be OK for older cars like your Prizm. It does help that the 4A-FE is a very durable engine like any 90s Toyota.
However, newer cars modern engine management can actually compensate for the thinner air and thus must use 87+ regardless of altitude. I would't be surprised if 85 gets phased out in the next 5 years or so.
For you, NP. But in general it may be a CP.
Of course, you can always try a tank of 87 and see what happens.
Merkin Muffley
> 7:07
04/24/2014 at 15:28 |
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at those altitudes, a lot of vehicles (especially old ones from the days of leaded gas) run better on 85 octane tractor gas. I would think that if your car was unhappy with it, the tractor gas would cause a CEL.
Chris Clarke
> 7:07
04/24/2014 at 15:32 |
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Using lower octane fuels than those recommended for your engine can lead to pre-ignition and detonation. Basically the fuel combusts before the optimal time in the compression cycle. Detonation is when the fuel explodes instead of burning evenly. This can cause higher pressures than engine components are designed for and can potentially cause engine damage. More modern engine have knock sensors that detect the preignition and can adjust the timing to compensate.
thebigbossyboss
> dogisbadob
04/24/2014 at 15:34 |
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The 4A was the toughest engine ever built. I ran one of those things 180,000 or so miles then into a truck at 50 mph. Still ran after. The L61 from chev is a good contender also.
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7:07
> dogisbadob
04/24/2014 at 15:34 |
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Naturally, I filled up with 85 just the other day. I'll be through with it in a week, then I'll try 87 octane a couple times. My last tank was 38.9 MPG, so I can't think 85 is doing nasty things to that cute little 1.6
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7:07
> RazoE
04/24/2014 at 15:35 |
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I'm not worried about the $$ savings, it's just always been a habit to use 85. I don't know why I haven't thought about octane ratings before now though...
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7:07
> Mattbob
04/24/2014 at 15:36 |
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Engine sounds fine. 172k miles. A little lifter noise in the morning, but it's fine otherwise.
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7:07
> MonkeePuzzle
04/24/2014 at 15:38 |
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Steelies! The stock wheel covers were all broken. It needs new headlights and 50 more HP, but it gets me where I need to go. Cheap to run too.
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7:07
> For Sweden
04/24/2014 at 15:39 |
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Manuel says 87. Just checked. Can't believe I didn't catch that before.
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For Sweden
> 7:07
04/24/2014 at 15:41 |
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Then you should be fine at altitude.
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7:07
> Jake - Has Bad Luck So You Don't Have To
04/24/2014 at 15:41 |
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It's next on the purchase list. My wife likes them (it will be her car), her harp fits, they seat 8, tow 5-7000 lbs, get 25mpg, have an LT1 and are cheap to buy. What's not to like?
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7:07
> Merkin Muffley
04/24/2014 at 15:41 |
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No CEL's. And yes, the light works :-)
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7:07
> thebigbossyboss
04/24/2014 at 15:44 |
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I wish this car had a taco-meter. There are places around here with 80 mph speed limits, and this little car screams at that speed. Especially trying to climb 3,000 feet in altitude.
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7:07
> Chris Clarke
04/24/2014 at 15:45 |
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Do you think higher internal pressure would cause seals to fail? I noticed my valve cover gasket leaking lately. Maybe that's due to 170,000 miles...
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Merkin Muffley
> 7:07
04/24/2014 at 15:54 |
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i'd say you're good. Just remember to fill up with 87 if you are going to come down off the mountain.
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Chris Clarke
> 7:07
04/24/2014 at 16:18 |
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Its possible, although valve covers typically don't last that long under normal conditions anyway. I would imagine there just isn't enough pressure going on inside that engine to cause any substantial damage, but over a couple hundred thousand miles you might notice some compression loss, most likely around the piston rings.
wiffleballtony
> 7:07
04/24/2014 at 16:24 |
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Manuel gives bad advice, try the manual
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Mattbob
> RazoE
04/24/2014 at 16:25 |
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lower octane doesn't mean shitty, it means lower octane.
If only EssExTee could be so grossly incandescent
> 7:07
04/24/2014 at 20:05 |
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That woody is giving me a woody.
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Jake - Has Bad Luck So You Don't Have To
> 7:07
04/24/2014 at 20:22 |
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I still find it amazing that the LT1 gets 25mpg in a car that heavy. I can barely top that in my 3.8l V6.