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914World.com _ 914World Garage _ What grade gas do you use?
Posted by: BahnBrenner914 Jul 11 2007, 01:52 PM
Just wondering what you guys use as I'm putting my tank back in and it says 91, but how important is that?
Posted by: Joe Ricard Jul 11 2007, 02:19 PM
as low as you can go without ping.
I ran 87 in my car 7.8:1 compression Ran better than when I used 89. was an absolute dog on 91.
Posted by: newto914s Jul 11 2007, 02:45 PM
the sticker in the tank is 91 Ron(Germain Standard I think) and when it's converted to Octane, how we measure our fuel in the US, it equals 87 Octane.
Joe's right, lowest Octane the car won't ping with, everything more leaves carbon behind when it doesn't completely burn.
Posted by: Johny Blackstain Jul 11 2007, 02:53 PM
the sticker in the tank is 91 Ron(Germain Standard I think) and when it's converted to Octane, how we measure our fuel in the US, it equals 87 Octane.
Joe's right, lowest Octane the car won't ping with, everything more leaves carbon behind when it doesn't completely burn.
I'm not sure but I think it converts to 89, not 87. Teeners ran on regular, "89 octane leaded gas" back then which is equivelant to mid/plus/89 today. I could be wrong on this since I've done no math but it makes the most sense to me.
Posted by: Joe Ricard Jul 11 2007, 03:39 PM
Sense or not. I used what worked for me.
my new motor will be a whole new learning experience with octane.
10.4:1 compression
Posted by: Gustl Jul 11 2007, 04:05 PM
the sticker says 91 - so I use 91
btw - our gas stations offer 91, 95, 98 and some of them even 100 ...
Gustl
Posted by: 914nerd Jul 11 2007, 04:25 PM
That's because the RON (research octane number) is higher than the R + N / 2 that the US uses
I think it translates to low grade fuel
Run as low as you can without pinging
Posted by: Blood red 914-6gt Jul 11 2007, 06:15 PM
I've been running 110 leaded the past year, and my car gas more snap than ever. When the engine was apart it looked very clean as well.
Posted by: Johny Blackstain Jul 11 2007, 06:25 PM
I've been running 110 leaded the past year, and my car gas more snap than ever. When the engine was apart it looked very clean as well.
Where may I ask, can you get 110 leaded? Must be $15.00/gal!
Posted by: newto914s Jul 11 2007, 06:42 PM
http://en.wikipedia.org/wiki/Octane_rating
Posted by: Blood red 914-6gt Jul 11 2007, 06:43 PM
A few stations here carry it. YOu have to bring cans to put it in as they cannot pump into your car. I have 5 five gallon cans I fill up when I need. It is 6.25 a gallon. The 100 unleaded is 12.00 a gallon.
Posted by: 9146986 Jul 11 2007, 06:46 PM
Joe's right on. We had a petroleum tech do a presentation at the Mid West Renegade Festival back in '96 and he said the same as Joe.
People started calling high octane "high test", which makes you think it's better right? Maybe for an old 327 Chevy with 12/1 compression.
The higher the octane the slower the burn. The higher octane, the more additives the fuel has in it, which ends up on the top of your piston and on you cylinder head. The more carbon build up you get means it raises the compression and you get carbon hot spots on the piston or cylinder head which results in pre-ignition, so you run higher octane fuel and the endless cycle continues.
Posted by: orthobiz Jul 11 2007, 06:54 PM
Joe's right on. We had a petroleum tech do a presentation at the Mid West Renegade Festival back in '96 and he said the same as Joe.
Say it ain't so, Joe! My new car is "poppy" with my foot off the accelerator while in gear and maybe it would run better on LOWER octane?? This I gotta try! Thanks,
Paul
Posted by: SLITS Jul 11 2007, 07:07 PM
Cheapest shit I can find!
Posted by: orthobiz Jul 11 2007, 08:38 PM
Cheapest shit I can find!
Hmm... Wonder if it's as harsh as the Utah shit that Gumby likes so much!
biz
Posted by: familienauto Jul 11 2007, 09:50 PM
We put 92 octane in ours. Previous owner said he put 87 octane in it once and it knocked real bad, so we just put premium in it.
Zach
Posted by: D1A3 Jul 11 2007, 10:08 PM
Check out my previous post on this:
http://www.914world.com/bbs2/index.php?showtopic=63083&st=20&p=805978&#entry805978
Porsche recomends ROZ91 whcih translates to 87 here in the US. No need for anything more than that unless your running something modified.
BTW: I always hear I have a fast 914 and am asked what mods have been done. I use 87 here in the US and think a properly maintianed engine and decent driving skills are way better than paying for the higher grade fuel unnecessarily. Save your money and put it into other areas of the car.
Posted by: grantsfo Jul 11 2007, 10:15 PM
110 leaded race gas
Posted by: 9146986 Jul 12 2007, 08:24 AM
[[/quote]
Say it ain't so, Joe! My new car is "poppy" with my foot off the accelerator while in gear and maybe it would run better on LOWER octane?? This I gotta try! Thanks,
Paul
[/quote]
I would say that doesn't have anything to do with the fuel. Sounds like an exhaust leak to me.
Posted by: shelby/914 Jul 12 2007, 09:05 AM
My '76 2.0L with FI runs just fine on 85 octane, which is regular at our altitude. It is also what my independent Porsche shop recommended.
Posted by: DownUnderMan Jul 12 2007, 02:43 PM
98 RON all the time, but it will run fine on 96. The 98 costs about US$1.20 per litre.
Posted by: BMartin914 Jul 13 2007, 08:35 AM
My '76 2.0L with FI runs just fine on 85 octane, which is regular at our altitude. It is also what my independent Porsche shop recommended.
Posted by: Gint Jul 13 2007, 10:25 AM
My '76 2.0L with FI runs just fine on 85 octane, which is regular at our altitude. It is also what my independent Porsche shop recommended.
Same here... anything more is just a waste of cash.
Posted by: BMXerror Jul 13 2007, 12:37 PM
Air cooled engine + hot climate. Premium for me.
Mark D.
Posted by: JmuRiz Jul 13 2007, 03:02 PM
Hmm, I've always ran premium, which is 93 octane here on the east-coast.
Question now is how do you get all the carbon/additive buildup out of the engine? Should I use some kind of upper engine cleaner or BG44K?
Anyone have any suggestions?
I'll fill up with 87 next time I need gas, see if it pings (BTW my car is a carb'd 2.0 with mild mods).
Posted by: akellym Jul 13 2007, 05:24 PM
I've always run 93 or higher. I don't have any carbon bldging up in my motor.
Posted by: Pat Garvey Jul 13 2007, 08:46 PM
I run 87 octane. No problems - it IS a VW motor after all. When I was in the Army (decades ago) I used to swipe the 5 gallon reserve cans of 65 octane MOGAS from my Jeep & put it in my 65 Beetle. Ran great & free.
Yeah, I know it was "not quite right", but the bastards yanked me out of college! All because I had a 0.8 accum. See "Animal House". I got over it.
Posted by: highways Jul 13 2007, 09:00 PM
89 seemed to work, and I think was recommended by the mechanic as well. However I do agree it's all a waste of cash which could be used on sooooo many cool parts.
Posted by: grantsfo Jul 13 2007, 11:38 PM
the sticker says 91 - so I use 91
btw - our gas stations offer 91, 95, 98 and some of them even 100 ...
GustlWe have some gas stations in California that offer 100 Octane at about $5.50 USD a gallon.
Tracks sell several grades up to 110.
I occasionally buy 5 gallon cans of 110 leaded race gas at a local speed shop for about $9.00 USD a gallon.
Posted by: Blood red 914-6gt Jul 13 2007, 11:43 PM
Wow, trick racing 110 up here is only 6.25 a gallon. At the track there is Sonoco and others you can buy, but they sell trick near my house.
Posted by: orthobiz Jul 15 2007, 08:06 AM
When I was in the Army (decades ago) I used to swipe the 5 gallon reserve cans of 65 octane MOGAS from my Jeep & put it in my 65 Beetle. Ran great & free.
Yeah, I know it was "not quite right", but the bastards yanked me out of college!
Umm, doesn't this belong in the "tell us your sins" thread?
Paul
Posted by: JPB Jul 15 2007, 04:38 PM
I run 93 since this is the high grade fuel here. I will go down as the engine can handle it. If you can put lead aditives in your fuel do it; specially on new engines. Use the grade that dosen't make your engine ping when all is tunes up. A little Marvelous Mystery Oil dosen't hurt either in your fuel to get rid of carbon deposits. 
Posted by: mikelsr Jul 15 2007, 07:13 PM
I run 93 in my modified 2.7L/6
Posted by: BahnBrenner914 Jul 16 2007, 01:19 PM
Seems to me that guys with stock teeners run the regular more and guys with built engines (ie higher compression) run premium. Does that sound like a reasonable statement?
Posted by: JPB Jul 16 2007, 06:55 PM
Yes you are correct brother except for me. I run premium to mix with all the oil it burns
Actually it is due to compresion ratio. When one gets to or passed 9:1, higher octanes are needed to keep air/fuel mixture from combusting ahead of timing as in pinging or preigniting.
Posted by: brant Jul 16 2007, 10:47 PM
My '76 2.0L with FI runs just fine on 85 octane, which is regular at our altitude. It is also what my independent Porsche shop recommended.
Dan,
you can get away with less octane at altitude. (and on cool days)
brant
Posted by: Lavanaut Jul 17 2007, 02:45 PM
Having only ever owned modern cars before I bought my teener last year, I've been feeding it premium. The car seems to run great, but apparently I've been suffering from a common minconception, that premium fuel is better/cleaner/whatever than regular. Maybe it'll run even better on regular! I love this site, I'm always learning stuff.
That said, I want to try out some 87. A lot of people have said something along the lines of "as low as you can go w/o engine knock". So what exactly to I listen/feel for? Engine knock is not something I've ever experienced, at least not as far as I know.
Because I understand it's a consideration, I'm driving a stock '74 2.0 @ 3500 feet.
And please, be gentle...like I said, I'm learning. 
Thanks
Posted by: Blood red 914-6gt Jul 17 2007, 11:57 PM
You should be fine running reg. Just make sure you are not going to stations that have chitty gas. I swear by Chevron, but shell and 76 are good. I have had to drain a few customers cars who said they only fill up at Safeway and other club stations. The detugents are what is really not good for these old cars. That is why I run 110 leaded in my six. So, go to Chevron and fill with reg and see how it goes. If it knocks it will sound like a pinging noise. It shouldn't though.
Posted by: krazykonrad Jul 18 2007, 11:34 AM
I used mid grade until I realized that mine ran as well on regular Chevron as anything else. I've got a 4 cyl 2.3.
BTW: Porsche recommends the Techron as a FI injector cleaner.
Posted by: Mark Henry Aug 18 2012, 06:00 PM
87 in the DD's, 91 Shell in everything else (including ATV, lawn tractor, weed eater, etc) because it has no methanol in it up here.
Posted by: KENNY Aug 18 2012, 06:47 PM
For the past 13 years I use premium . Never had a problem whit my car .
Posted by: 914Bryan Aug 18 2012, 07:43 PM
I run 91 octane with a little Marvel in tank. The premium gas is to avoid any possibility of pinging and the Marvel is to keep the valves clean. I have heard that the premium fuel does not contain any methonal in it and some lower grades do. I am not an expert with this, but that is what I have seen labeled on the pumps. With old fuel systems I think methonal in any amount is taboo. Just my opinion.
Posted by: iamchappy Aug 18 2012, 08:40 PM
93 nothing less for the turbo teener
Posted by: rnellums Aug 18 2012, 08:44 PM
Back in 2007 when this thread last came up I was running 91. Now I'm still running 91.
Posted by: euro911 Aug 18 2012, 11:40 PM
I've read that newer computer-controlled FI engine management systems may take up to three tanks of fuel to fully adjust to optimum settings, not sure about early 70's technology?
I use to run 87 in both of our [stock] 914s, but run mid-grade in the recently built 2056 (9:1 CR).
I agree, you can run a low grade but avoid pre-detonation, and watch your temperature readings. If you change the grade of fuel, be prepared to readjust your timing (and jetting if running carbs) to account for the difference.
Posted by: Ian Stott Aug 19 2012, 04:13 AM
I don't want to use the ethanol enhanced fuel so I use high test which is around 91 octane where I live, the regular 87 octane does have the ethanol and I really want to stay away from that stuff. The extra few cents per litre is worth it to me, just for piece of mind, I want to go for a trouble free drive, not worry about what's in the tank. I find a lot of the older mechanics all use 91 octane, they feel it is the better way to go, sometimes experience is a good indicator even though they may not have graphs and computer printouts to back up what they are saying.
Ian Stott
Moncton
Canada
Posted by: brant Aug 19 2012, 11:58 AM
I believe with current US emissions (especially california)
all grades of gas should now have ethanol
if I am wrong then good for you
but I know in Colorado this is true and all grades of gasoline have ethanol.
I thought this was the federal standard in the currently required, subsidized, energy and fuel plan that Mr. Bush left for us when he signed it into law in 2007.
So the question really is about what grade of fuel your motor and octane require
I don't believe there is any way to avoid the ethanol (not methanol as one poster mentions)
Posted by: JamesM Aug 19 2012, 12:34 PM
You have to search to find it but if you are lucky you can still get ethanol free gas.
I run 92 Sunoco (etahanol free) when i feel like driving to the other side of the valley to get it. If I don't (or cant) get all the way over there to get it ill run 87,88 or 89 depending on what the station has.
Posted by: brant Aug 19 2012, 12:45 PM
You have to search to find it but if you are lucky you can still get ethanol free gas.
I run 92 Sunoco (etahanol free) when i feel like driving to the other side of the valley to get it. If I don't (or cant) get all the way over there to get it ill run 87,88 or 89 depending on what the station has.
and I would guess that one station that you use for ethanol free, probably has a label right on that pump that states it is not legal for highway use.
I think they are selling it as an "offroad use" fuel
if I could get it, I would do the same.
maybe with the draught someone in washington will realize they need to repeal this law. Although I doubt the corn growers would feel that way.
Posted by: jsayre914 Aug 19 2012, 01:30 PM
I am running 91 in my 2056, I also use mystery oil in every other fillup.
Runs like a champ
Posted by: 914Bryan Aug 19 2012, 02:43 PM
I believe with current US emissions (especially california)
all grades of gas should now have ethanol
if I am wrong then good for you
but I know in Colorado this is true and all grades of gasoline have ethanol.
I thought this was the federal standard in the currently required, subsidized, energy and fuel plan that Mr. Bush left for us when he signed it into law in 2007.
So the question really is about what grade of fuel your motor and octane require
I don't believe there is any way to avoid the ethanol (not methanol as one poster mentions)
Ahhh! My bad, meant ethanol....Hanging out at the drags too much!
Posted by: euro911 Aug 19 2012, 04:02 PM
Posted by: Ian Stott Aug 19 2012, 04:04 PM
The 91octane pump (high test) says on it "ethanol free", the 87 octane pump (regular) says it contains 10 or 15% ethanol, I'm not sure which as I don't use it, maybe it's the law in Canada that they have to post the info. I used to run the refuelling section at Canadian Forces Base Greenwood in Nova Scotia and have had a few courses re. fuel, not just gasoline. I agree you only need to run the octane required for your engine not to knock/ping, but I have been running the 91 since the ethanol thing and like I said in a previous post, all those old mechanics that actually tear engines apart are running the 91. I know if I use a corner store gas bar of no name gas it isn't the same as Shell Gold, so that is what I use in all my vehicles.
Ian Stott
Moncton
Canada
Posted by: Jeffs9146 Dec 4 2012, 06:42 PM
I voted for 91 but I am running an 83sc 6 and from what I have read they bumped up the HP to 204 with all the smog/exhaust stuff! I have since removed all that and added headers. The specs on the later 80 to 83 sc's said to use 91!
Posted by: eyesright Dec 4 2012, 06:46 PM
You can buy a fuel tester on line, but I bought mine from the local Briggs and Stratton parts shop for $8. I test the fuel now and then when I buy gas for the lawn mower. The pump sticker says "contains up to 10% ethanol" but I haven't found any alcohol content here in OK for a couple of years and lately the stickers have disappeared at many stations. A few of the Fina -- now Alon -- stations here have a pump for 100% regular and another for 10% ethanol regular.
And I just bought 3 testers for Christmas gifts for fellow enthusiasts. And you can make one with a test tube from your kid's chemistry set.
Anyway, my 914 and '86 911 run fine on regular. And I like MMO a couple of times a year. It smells better than the other stuff, but its all "petroleum distillates" which I think usually means fuel oil, jet fuel, diesel, kerosene, etc.
Posted by: jersey914 Dec 4 2012, 08:30 PM
Premium........it's a freaking Porsche.....Come on people
BTW, I run Marine stabilizer in every tank too......Ethanol is not our friend
Posted by: '73-914kid Dec 5 2012, 12:06 AM
Premium........it's a freaking Porsche.....Come on people
BTW, I run Marine stabilizer in every tank too......Ethanol is not our friend
Just because it's a Porsche, doesn't justify running expensive gas. If it doesn't ping on 87, run 87. the quality of gas does not improve as the octane increases, unless there's an increase in ethanol content as the octane goes down.
Plus, 914's have vw engines...
No need to spend extra for wasted octane...
Posted by: zymurgist Dec 5 2012, 09:29 AM
2.0 D-jet, 87 octane
Posted by: billh1963 Dec 5 2012, 10:07 AM
I've tried everything from regular to super unleaded. I never noticed a difference. Just use regular now
Posted by: Ductech Dec 5 2012, 06:06 PM
I drive a conversion in a conversion that's wrapped up like a Taco Bell double decker turbo death burrito...
So premium is required. Know your overal pressures your dealing with. High comp will require it. Most stock type 4's properly tuned could run happy on regular forever.i imagine when you consider the compression ratio and quality of gas at the time of manufacture. But as I've made an ass of myself before.. I could be totally off.
Posted by: 442nd914s Dec 7 2012, 09:30 AM
What if you're running an MSD system on a original FI '73 2.0lt? I just had mine rebuilt to a 2056 and will be crancking it up soon after 20 yrs of rest. What grade should I start it at and for how long?
New rings, cylinders, redone heads, MDS coil, wires, plugs, Plantronix .......kitchen sink wouldnt fit.
Posted by: Vacca Rabite Dec 7 2012, 03:52 PM
Always run the lowest grade gas that does not cause your engine to ping.
My 2056 needed 93oct gas when it was at 9.2:1 compression. Its new form will be 8.6:1 compression and I will need to determine what grade gas to use when its running. If it does not ping on 87, thats what I will be using.
Remember, the lower the octane, the more energy the fuel has.
Zach
Posted by: Robert21 Dec 9 2012, 03:07 PM
Do what makes you feel better. I will sent my money on other things. 87 for 9 .
years . Runs fine .
Posted by: SirAndy Dec 9 2012, 03:44 PM
At 11.3:1 compression, i always look for the highest octane i can get. Around here, that is 91.
Posted by: gunny Dec 9 2012, 03:54 PM
87 octane here
Posted by: jersey914 Dec 9 2012, 06:14 PM
At 11.3:1 compression, i always look for the highest octane i can get. Around here, that is 91.
Andy, what do I need to do to find the compression #s on my 2.0? Just wondering....I run 91 in mine and it seems to run great. It's been worked a bit so I doubt it is standard compression.
Posted by: Vacca Rabite Dec 9 2012, 07:10 PM
Jersey - you would have to pull the heads off and CC them. Its somehting you do when building the engine in the first place.
if it runs great, just go with it!
Zach
Posted by: SirAndy Dec 9 2012, 07:37 PM
If it's a stock motor, the compression should be 7.6:1
If it's not stock, Zach already said it, you'll need to cc the heads.
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