| Author |
Message |
Mike (Busone)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 13, 2005 - 8:49 pm: | |
Here is a question for the experts of this excellent board. Here in the Denver area our gasoline is available as 85, 87, and 91 octane. My 97 Saturn manual says to use a minimum of 87 octane regular gas. Some have said since we are at such a high elevation we can use the 85. Others have said that is only true in carbureted vehicles. Anybody have some advice. The 85 is a lot cheaper and prices are high. |
Jim Stacy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 13, 2005 - 9:00 pm: | |
The 85 will work just fine at your altitude. The computer and knock sensor will allow it to work at lower altitudes as well if necessary. The 87 will work better at higher air pressures.
Jim Stacy |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 13, 2005 - 9:00 pm: | |
I was told that without the lead, any grade will do, so I've
been running the el'cheapo grades in every gas vehicle we've
owned. From a Chevy 454 to the Mercedes, to the Caddy,
the cheap stuff's been absolutely great. |
Mike (Busone)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 13, 2005 - 10:29 pm: | |
Thanks guys that is good to hear. I will try a few gallons when the tank is nearly empty. If it don't knock I will switch to the cheap stuff. |
Chuck Newman (Chuck_newman)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, August 14, 2005 - 12:09 am: | |
Mike,
Your Saturn is fuel injected and has a knock sensor.
As Jim and John say, you won't have any problem.
If you had an '83 Toyota with 200K + miles like mine, it would probably knock like mine. I have to run 92 octane in it or it will sound like a diesel, and preignition is very bad for a gas engine.
Chuck Newman
Oroville, CA |
Ian Giffin (Admin)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, August 14, 2005 - 10:18 am: | |
Hi Mike,
Gas is reported at a low of $2.21 at Bradley Food Mart at 2698 W. Alameda Ave and $2.59 at Conoco near Santa Fe & Town Centre.
Given a fill of 15 gallons, we're talking about a difference of about $5.50 a tank.
Ask yourself if that weekly fiver is worth it to void the vehicle manufacturer's warranty. Oh, and make sure you've priced out a re and re for an engine in your Saturn, so you're not paying through Uranus for a new one.
Ian
www.busnut.com |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, August 14, 2005 - 10:42 am: | |
Yup, it's funny when flatlanders come through and accuse us of watering-down our fuels.
Mike, your knock sensor will indeed retard the timing to avoid preignition, but you'll also suffer lower power and lower MPG. Higher grade fuel might make the $/mile a wash. Case in point: My fuel-injected '87 van gets 11MPG on reg. and 13MPG on mid-grade. Amazingly, my bus that's twice as long and about five times heavier gets almost 10MPG.
Oh, and I've found it's even cheaper per gallon to buy octane boost at an auto parts store and add it at fillup than to pay for premium fuel. It's between $2 - $4 a bottle.
HTH,
bb
Longmont, CO (Elev: 4979') |
gusc
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, August 14, 2005 - 5:15 pm: | |
I just read an article in the newspaper that more and more people are skipping the higher priced grades and buying regular, even for vehicles rated for high octane only.
As some of the previous posts have said, the sensor/computer system takes care of lower octane so no problems there. |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, August 14, 2005 - 10:13 pm: | |
The 454 in the '85 Winnie didn't have a knock sensor. Manufacturer
says to use high test. I ran looooow test. No knock after I tuned
it to the low test. Ran great. Same with the 454 in the Georgie-Boy.
Just time it after you've run a tank through and filled it again. |
David (Davidinwilmnc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 15, 2005 - 8:35 am: | |
I've never seen an octane rating of 85. We have 87, 89, 91 and occasionally 93. Are the ratings calculated differently in various parts of the country? Also, some premiums (Amoco) have more detergents, FWIW. |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 15, 2005 - 10:03 am: | |
David, octane rating decreases with altitude. With the same anti-knock additives as low-altitude gas, our regular is 85, mid-grade is 87, and premium is 89.
All fuels' effectiveness is lessened because there's less oxygen to burn, so we have to de-rate everything that's fuel-burning (appliances, etc.). Plus, cooking things has to be adjusted, as well (water boils at a lower temp., yeast rises slower, etc.)
The price to pay for living the "high life", I suppose.
HTH,
bb
Longmont, CO |
David (Davidinwilmnc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 15, 2005 - 10:38 am: | |
Brian,
We're certainly much lower (altitude wise) than 'most anybody, being that we're just a few feet above sea level. It sure makes a lot of things easy. I remember being in CO a few years ago. I almost couldn't catch my breath going up and down stairs at our hotel... and I am (was, actually) in really good shape. |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 15, 2005 - 11:22 am: | |
Sensitivity to altitude is fairly common, David. It affects certain people and not others, and is generally independent of one's physical condition. I believe it has a biological component of how one's red blood cells deal with reduced oxygen. I've even read that those that live at higher altitudes actually have physical changes happen to their red blood cells to adapt. Wild!
Most folks can adjust to altitude, given time and moderation. Best thing to do if afflicted is to take it easy... watch your caffiene and alcohol intake, since these will worsen the affects.
I have a buddy from Dallas (where I grew up) that vomits for a few days every time he comes to ski with us (which is up at about TWO miles high). I always wonder why he keeps coming!
bb |
Dale L. Waller (Happycampersrus)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 15, 2005 - 9:49 pm: | |
I love altitude, especially today. It was in the high 90's down below the mountain in Charlotte NC. High 70's here.
Dale
High on top the Blue Ridge Mtns in Va. |
Mike (Busone)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 18, 2005 - 10:58 pm: | |
I nearly ran my car out of gas. I then added 3 gallons of 85 octane. Just as you all said it is fine. I can't even tell the slightest difference in power. I am also getting the same mileage. Now I can save 10-15 pennies when I fill up. |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 18, 2005 - 11:12 pm: | |
Yeah, but it's going to void your warrantee, cause your dog
to choke on a chicken bone and your wife will run off with
the pool guy. Don't say you weren't warned. |
Henry R. Bergman, Jr. (Henryofcj)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 19, 2005 - 5:45 pm: | |
Living way up high in mile high Denver CO, yeah, you can use the 85 octane gasoline in either a computerized newer car, or in the older (1980) low compression cars without a computer.
Years ago when I used to work summers at Yosemite National Park sometimes I would drive the relief route from the Valley Floor up over Tioga Pass (9910 ft) going to Reno.
The bus was an old 4104 with the low gearing, plus an added neat (for its time) turbo, plus a Jake Brake which was really neat coming down the Lee Vining grade.
Anyway, I babble. Common problem nowadays. At the pass (9910 ft) we would stop and run at high idle for about 10 minutes to let the mill breave and cool, plus let the old foggies (passengers) out for a pic taking thing.
Some of them would take a dozen steps, then keel over from the altitude. We had an O2 bottle on board and we had to be cerfified first aid persons. Don't let high altitude get ya. |