Cliff92Z

I always put Amoco clear 93 octane in my baby and once in a while I'll use Chevron.

Which do you find better for your car?
What should we stay away from?

------------------
1992 Z28 (305) TPI.
160' stat, Accel 8mm, Accel Cap & Rotor,
Flowmaster, high-flo cat.
700R4 3.73's HD Zexel Torsen

Spyder

I always put in SA or Holida 92/93 oct. I try and stay away from the "discount" places. Then again, I don't notice the differnce but I have some friends that work there and they always tell me horror stories.

Mark305TBI

I don't know how great of an idea it would be to let your baby drink gasoline...gas is a pretty toxic substance .

Amoco Ultimate.

-Mark W.
'88 SC Camaro w/ 305 TBI

Cliff92Z

Is it true to have the timing advanced to justify using premium gas? I heard that it can foul your plugs and that 160* thermostat probably makes it worse forcing you to run rich all of the time. Anyone heard this?

------------------
1992 Z28 (305) TPI.
160' stat, Accel 8mm, Accel Cap & Rotor,
Flowmaster, high-flo cat.
700R4 3.73's HD Zexel Torsen

Bort62

Higher Octane gas Burns Slower, because of this it allo You to advance your Timing to ignite the mixture Earlier To take ful advantage of the Combustion, and have all combustion finished in Time. meaning More power and fuel efficency.

So With Higher Octane gas, You can Give it more advance than with a lower octane.


thats assumeing compression is equal, thats another related issue.




------------------
60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

Bort62

Rahter I should Say compression Figures into This, To determine How close you can get to "optimal" advance before Spark knock occurs. With Low compression And low octane gas, You can run as much timing as High compression, High octane gas setup could.

High octane gas In a low compression Motor that Was already able to acheive Max optimal advance With Low octane isnt gonna do a damn thing.


sooooooo.....


It all depends on your setup

You could run ( hypotheical, dont quote my actual numbers ) 35* total On 87 In a 8.0:1 Motor And 35* total on 93 in a 9.5:1 Motor and Be at optimum advance with No spark knockk In both Motors, The higher compression Motor Will make More Torque and therefore horsepower, However.

hence the advantage of higher compression and higher octane gas to match

EDIT :

damn, I never stop.

Following that, More Torque For The same amount Of fuel combusted = More efficent, And that torque will allow you to push a steeper gear Attaining higher speed at a given RPM ( and fuel consumption), Wich Will lead to better Milage, SO yes Higher octane fuel leads to better Milage, Sometimes


------------------
60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

[This message has been edited by Bort62 (edited April 06, 2001).]

Kevin Irving

Amoco 93 and Amoco 93 only. nuff said.

------------------
Kevin Irving
85 Trans Am WS-6, 305 TPI, custom burned '86 PROM with '87 "165"ECM, Accel Supercoil & 8.8 Wires, MSD 6AL, Aluminum Driveshaft, Wonderbar, TB Coolant Bypass, Ported Plenum, Modified MAF, Syclone Fuel Pump, JET Airfoil

15.556 @ 86.65mph, Nov 10, 2000.... I know it sucks.. but it will get better!

http://www.geocities.com/transam85tpi/

Member - The Tidewater Trans Am Club, Norfolk VA http://www.geocities.com/ttacva/

camaro6spd

Have any of you been able to use 89??

Nonni

Usually I use 95 octane.

Once I tryed some (small) aircraft fuel on my 305HO (L69, holley carb), it was mostly ok, but my T/A didn´t idle (had to keep my foot on the gas).

I tryed that on my Blazer with 350 and that works great. I can´t understand why the aircraft fuel dont work on the 305 but works on the 350 (edelbrock carb). The aircraft fuel is 100 octane, isn´t the aircraft fuel rated like the car fuel?

Later,

Nonni

Macgyver

93, wherever I can get it, it's getting harder to find anymore.. 92 is the "Super" around here..

I really should bring the timing back down so I can at least run 92..

phantazy82

i run 89 all the time and i have no troubles what so ever.

------------------
1982 Camaro SC-Z hybrid

88305tpiT/A

iTrader: (2)

if you are talking about jet fuel its based on kerosene and will mess up your motor but if you just use the prop planes gas I think it needs some additives that are in normal gas to run in a car motor right.

Nonni

I tryed aircraft gasoline intended for small planes (not jets). What I don´t understand is why it does not work with my 305HO when it it works for my 350 and my brothers 455. I dont know the compression on the 350 but it is around 9.5:1 on the L69.

Where I live the regular is 95 octane, premium is 98. But we pay a lot for our gas

mtx28

Avgas(aviation gas) is just like normal gas.. but 100+ octane. in other words, no additives needed. why you all running such high octane , assuming your compression is less than 10:1? i thought (generally) you stick with less than 93 until you get higher than 10:1?

------------------

• 83 Z28--ttops, 200k miles--very ragged out. sold, thank goodness
• 74 Z28--slightly modded 383, TH400 tranny, not too quick but fun to drive

vortech305

How about mobil or the one with the tiger(forgot the damn name)

------------------
92' camaro
New 305 block TPI conversion, Flat top pistons,Bore over .30 Forged parts all around,Edelbrock intake,ported plennum,ported corvette alluminum heads, accel cam,52mm throttle bodie, SLP runners Home aid cold air induction, Air foil,ford SVO 19lb injectors,fuel regulator,cloys timing chain, comp alluminum roller rocker arms and pushrods MSD 8.5 mm wires, bosch plattinum plugs, hypertech cap & rotor and coil, Edelbrock TES headers, free flowing catalytic converter and a 3 inch force II flowmaster exhaust system, and a 3 inch cutout,Zoom multi friction clutch, T-5 tranny,billenstien shocks&struts.
Soon to come!!!
Procharger system 12lbs o boost.
New paint job(hawaiin orchid purple)Cast alluminum ZR1 rims w/ 275 tires.
Favorite quote: "where ever u go, there u are"

Other car;
1971 plymouth Duster
Mods:340,edelbrock victor jr. intake, 650 4 barrel holley, heddman headers,40 series dual flowmasters, cold air intake,4:10 gears, just got a new paint job and cragar rims with 315 tires in the back.
:Yeah its not a chevy but damn how many 71' dusters have u seen in the streets.

JoelOl75

Amoco Gold 93 or Sunoco Ultra 94.

In the 2.8 I use Sunoco 87.

NEVER use avgas with Nitrous!!!!

BOOM!



------------------
'88 Camaro RS 2.8L
'88 Formula 350 (Too many mods to list...)

camaro6spd

AV gas is different for automotive. I have talked with pilots and i am not sure wat it is. It has something to do with that the carbs in planes can adjust the fuel mixture while cars cannot. 9.5... you would only need 89 right, then why use 92 or 93 and up? makes no sense, wasting money and premuim gas burns slower too, if you have carbon buildup, clean it out. just my opinon

JoelOl75

Something about nitrous causing avgas to fall out of suspention (because of the cooling effect) and running the motor lean.


I know the octane rating is totally diff for avagas having something tot do with the ron and mon.

It works great in n/a cars. Turns the plugs orange though i noticed, and heard it contains trace (low lead) additives which can hurt the o2

87RS402

Altitude has alot to do with octane requirements too. I live at 4100' elevation and can run Chevron 92 around here but if I go to a lower elev. I have to add 1 gallon of toulene to every tank to bring the octane up. Of course I'm running 10.4:1 CR too.

For some reason my car likes the chev brand juice. Texaco, BP, shell, etc, all knock more to my untrained ears. Stay away from the cheapo depot stations, you don't know what your getting there.

BigMike 92 Z28

I only run Chevron 92- Once in a while ill run a little Toulene in the tank to clean everything out( injectors, fuel system, etc. ) and raise the octane( but i dont feel a performance diff ).

------------------
1992 Z28 W/5.7L. Teal with unpainted cowl hood,18" Billet Specialities Rims,Eibach Sportline Springs, Leather int., B&M Mega Shifter, Headman Headers, Flows,No Cats,K&N,HyperTech air foil,Custome Burned Chip,MSD Ignition,Shift Kit, Billet Corvett Servo my Back License plate reads "ALL UL C"

Here's a pic of my car
http://www.geocities.com/jonnyarson/maro.jpg

" HaHa- You just lost to a car with over 100,000 miles on it "



[This message has been edited by BigMike 92 Z28 (edited April 08, 2001).]

jobryan26

BudLight(me and wife), Cars 93 only

------------------
'87 Trans Am:
(Engine)
305 TPI
160 Degree Thermostat
TB Bypass
Accel 300+ 8.8 Racing Wires
Accel Super Coil
Bosch Platinium Plugs
Custom Ram Air with K&N
Removed Emissions Equipment & Cat.
(Stereo)
Kenwood Excelon

Grim Reaper

Chevron 94 Supreme Plus.

With a stock eprom, the conservative timing makes anything over 89 pointless.

bubbz89

93 octane

88irocz28

I used 87 a few times with horribly retarded timing, and although I couldn't hear any knocking, there was a noticeable power loss. I haven't run the car or anything but 93 since I set the timing back at 6* BTDC (or was it 8* ), so i don't really know whether it will knock or not but I do remember that when I was setting the timing late last year, I was getting pretty bad knock at 10* WOT acccleration with 93 octane.

How much octane are we supposed to run on these cars anyway? I agree with the others about not wasting money on extra octane we may not need.

------------------
'88 IROC 305 TPI
Crappy 700R4 slushbox
Gutted airboxes
180 degree T-stat
Advanced base TPS voltage
Relocated IAT sensor
Momo steering wheel (gotta luv it)
Ram-air setup coming soon
Flowmaster muffler (puke)
Taylor SpiroPro wires
Accel cap and rotor
Ported plenum
Kills: '94 Z28, Olds Aurora V8, bunch of Mustangs, T-birds, ricers, and others who assumed a 12 year-old car would be too slow.

[This message has been edited by 88irocz28 (edited April 09, 2001).]

Jza

Amoco 93 mostly. Exxon or Chevron occasionally. Never Citgo, Texaco, or anything sold at a Conoco, Tom Thumb, Circle K, etc. Bleh. BP sometimes if pressed for fuel.

3RDGENFRANK

I put in 87 octane whenever I need gas at the nearest gas station. I have never felt a noticable difference from brand to brand. If I could afford it, I'd probably use Amoco. If you are not running high compression, or not getting spark retard with 87, there is no reason for using 92/93 octane except for maybe the detergants. Its a proven fact that using a higher octane fuel than that which is required will reduce power. More spark advance is not always better either. You want to make sure you run the most for a given fuel, but low advance numbers indicate an effecient running engine. Higher octane and more timing do not equal an increase in horsepower. High octane is used to combat detonation on high compression engines. Correct me if I'm wrong in this thinking. What is the difference in running more timing to ignite a higher octane fuel, or less timing to run a lower octane fuel. They both have the same energy, the both are completely burnt if the timing is set appropriately. Comments?

------------------
1992 Camaro Z28; Engine:383 w/Ported Edelbrock RPM heads. Lunati Solid Roller Cam 224/232 .502/.502, Fluidampr, Comp Cams 1.5 Roller rockers and lifters, Comp Cams Triple Valvesprings, SVO 30 lb injectors. Holley/Walbro 255 lph in-tank pump, Haltech E6GM DFI, SLP 1 3/4" headers, 4" Mufflex, T56, SLP Clutch, Pro-5.0 Shifter, 4.10 Gear, Auburn Offroad Pro Posi. Super Ram. 17" X 9.5" Ronal FireHawk Rims w/ 275 40ZR17 Bridgestone RE 730's up front and Nitto Drag NT 555R's out back.

Double-Pump This! EFI Rules!

Bort62

There is So much Misinformation here...


The point of running A higher octane Fuel is it allows You to Run More spark advance For your Compression Ratio.

Now, Obviously there is a Point at wich Spark advance reaches an optimum point. At this point increaseing octane wont Do you any Good, your Right.

however, The stock Setup on these cars, as Glenn pointed out, is Sooo conservative that You can easily Wangle a few more ponies out of them by Getting a little more timing.

The higher octane gas itself does not yeild more power, Only allows you To Run more advance for a given compression. More Spark advance yeilds a more complete Burn, and therefore more power, To a point obviously ( ~ 35* BTDC )

Now For the guy who said his spark knock was altitude dependant, Duh.

Less dense air Will end up effectivly lowering your compression, thats why you can get away with 94 or whatever at 4,000ft but get knock when you come down to sea level. Same reason you Rocky Mountain guys Post you "Corrected" Times As opposed to track times


Now, whoever said that a Efficent engine Is one that runs will low spark advance on Low octane is full of ****. An efficent engine is one that makes the most power For the least amount of fuel consumed, That would be a high compression Motor Burning High enough octane gas To acheive optimum spark advance Without Knock.

Making the most ft/lbs per CI of air/fuel mixture that is burned, due to the fact that the mixture under higher compression, Will "explode" more violently.

Now, as for Too High of octane fuel causeing a decrease In power, that is true theoretically, but Not practically in our application. Maybe if you had a 7.0:1 compression Smogger that would allow you to run enough advance to acheive complete combustion Using 87, then yes With 92 you would be at a disadvantage because combustion would not be completed due to the Slower burning nature of the higher octane gas.

But, considering our application, If I can still get knock with my LG4 on 92, and Not be at Optimum advance, Then It would stand to reason that all you with L69's, L98's and Lb9's, With your higher compression, Could stand to gain a bit of power W/ advanced timing and Higher Octane.


Sure, I could Detune My motor and run just fine on 87, And even save .10$ every Gallon, But I would Suffer a huge decrease In power.

Not Worth it To me, What are we here for anyway ?

If I was in the buisness of gas efficiency at the sacrafice of power, I would Drive a Honda.



------------------
60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

Trigger84

I run 93 in mine. I'm not really brand loyal. I cant feel or tell a difference between any of them.

------------------
---Grady---
1984 Berlinetta.
LG4 305, 170 hp.
Rochester Quadraje(Comp. Controlled)
TH-700R4.
Flowmaster 80 series/ 3" cat-back pipe.
Accel Superstock Coil.
7.5 10-bolt rear/ 3.08's.
Edelbrock signature series air cleaner -w- K&N Filtercharger.
Pioneer head unit, Pioneer front 4X6's, Cerwin Vega rear 6x9's.
Daily Driver.

Mkos1980

iTrader: (8)

I usually run 87

------------------
89 FORMULA 350 Edelbrock Cat-Back ,March Pulleys,Super Coil,MSD 6AL ,Edelbrock TES's, AFPR ,Shiftkit, Edelbrock Base ,AS&M Runners, Edelbrock Waterpump, MSD 22# Injectors ,FastChip ,Hoping for 13.5

Guest

Mine always gets 87.

302GT_killer

the manual for my 90 camaro says that the 305 TBI, 305 TPI, and 350 TPI ALL have a 9.3:1 CR but only the TPI motors should get 92 while the TBI should get 87-why? i just say screw it and put 92 in my tank since i got the same compression as the other 2

------------------
soon that white 5.0 lx at school will get a good waxing from a nasty 355 RS...heheheheheh

Anniversary-SS-man

My cars always get Shell 93, if no Shell around, then Amoco 93.

------------------

• 1997 30th Anniversary SS LT4 #74 with all SLP options and K&N, white gage faces, and Hotchkis shock tower brace - In process: SFC's
• 1996 Corvette Grand Sport LT4 #509 with K&N, Flowmaster exhaust, Hypertech power programmer, and Baer slotted/cross-drilled brakes - In process: SLP throttle body and 1-3/4" headers, AFR heads, 4.10 gears, custom Panasonic/Alpine/Audio Control/ADS audio system
• 2000 Chevy TrailBlazer

David M

Chevron 92 octane or Amoco 93.

87RS402

Next time I'll be sure to include a long essay on why I bring up a point so others won't infer I'm an idiot.

And for the record I prefer the statement "Doh, Bart!"

bottledpower

im going to be the oddball in this chain. 110 octane with NOS. O-YEAH!

------------------
85 IROC 350 11:1keith blacks,.555lift erson roller cam,1.5 crane roller rockers,edelbrock intake,holley 4150 750dbl pumper, nitrous oxide,full length heddman headers,true dual exhaust, 11"stall converter, 700R4, 3.73 locker

rondubbs

92 or 93 any brand except those generic stations..

bbtaz97

iTrader: (3)

well i use only 93 form either mobil, amaco , or shell. ya they cost a little more but there are less additives as well.

------------------
91 camaro RS
- 305 TBI
Mods: Performer tbi intake, 1" TBI spacer, K+N, jet fan switch ,160 thermo,Accel control module, Jet Stage 2 chip, edelbrock TES headers, Compleate 3" Flowmaster exhaust, Edelbrock springs, KYB struts and shocks, 700R4 built by TSI, SLP tq converter

Soon to come .SLP Posi 323 rear end , Spohn LCA's and panhard bar , Ascd ram air hood, Z28 spoiler and grille , white guage faces.

Corry

Hmmm no texaco fans here? I usually use whatever the local texaco's highest octane gas is.92-93

------------------
Corry Lazarowitz
clazarow@voicenet.com
clazarowitz@hotmail.com
SLP 1 3/4" headers, 3" cat back (stock cat )MSD ignition. MSD Blaster SS coil. More soon when funds are avail...

rezinn

I do NOT go to texaco or USA or Arco. Mostly '76 89 or 91 octane. I trust those guys and chevron the most.

camaro6spd

how many of you guys that run the 92 and up really need it??

vortech305

i Use exxon or hess are any of these good. I use them cause of their prices. But if their gases gonna harm my motor i think ill go to another any suggestions of gas stations and octane for my new motor in the sig. I have about 9:6:1 compression.

------------------
92' camaro
New 305 block TPI conversion, Flat top pistons,Bore over .30 Forged parts all around,Edelbrock intake,ported plennum,ported corvette alluminum heads, accel cam,52mm throttle bodie, SLP runners Home aid cold air induction, Air foil,ford SVO 19lb injectors,fuel regulator,cloys timing chain, comp alluminum roller rocker arms and pushrods MSD 8.5 mm wires, bosch plattinum plugs, hypertech cap & rotor and coil, Edelbrock TES headers, free flowing catalytic converter and a 3 inch force II flowmaster exhaust system, and a 3 inch cutout,Zoom multi friction clutch, T-5 tranny,billenstien shocks&struts.
Soon to come!!!
Procharger system 12lbs o boost.
New paint job(hawaiin orchid purple)Cast alluminum ZR1 rims w/ 275 tires.
Favorite quote: "where ever u go, there u are"

Other car;
1971 plymouth Duster
Mods:340,edelbrock victor jr. intake, 650 4 barrel holley, heddman headers,40 series dual flowmasters, cold air intake,4:10 gears, just got a new paint job and cragar rims with 315 tires in the back.
:Yeah its not a chevy but damn how many 71' dusters have u seen in the streets.

Aaron87SC

When I gave my baby gasoline it started coughing and turned blue... Then I went to jail...

Grim Reaper

Camaro, I have heavily modified my eprom and I am running a lot of spark advance at this time. How does 17.4:1 and 47* in Highway Mode grab you?

This is all part of my experimentation to obtain max performance and max economy. It's more for protection against detonation. Once I have set a "base", I then plan to experiment with lowering the octane until detontation is detected and then determine how much (if any) retard I need for each lower grade of gas to avoid detonation while maintaining performance and economy.

My goal is to achieve similar performance and economy while being able to run 87.

Bort62

whoa whoa your at 17.4:1 Glen ?


Running 47* in highway mode, at RPM with No accelleration load I assume/full vaccum ?


Impressive.

You Spark curve must fall off VERY rapidly under load however, Right ?


Do you find a performance advantage With the higher compression and Retarded timing ?


At cruise 47* is almost ideal, But what does your advance fall to under load, were theoretically it matters most ?

Send me an Email, this is interesting



------------------
60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

Ragin'87

though I just got the 92.. and havne't done a full tune up, and checked timing and all. I have had enough time to go through many tanks of gas. The previous owner ran 93octane, 18.6mpg, most mileage on the freeway from Austin to Houston. When the tank was empty, and after I had changed from 20w-50(previous owner) to 10w30(no leaks, thank god.) i filled up w/ Exxon 89octane, 19.5mpg avg. one tank of Mobil 87 got me 17.9mpg, as did a tank of Exxon 87. The tank of Mobil was in during an Auto-x, and I've driven her pretty hard the last tank and a half. I have access to an OTC scanner, and I've done the driving computer scan a few time, with each gas grade. All parameters stay in optimum ranges, and I haven't gotten spark retard with any grade..

per my dad's advice.. I use gas in this order..
Exxon
Mobil
Shell
Texaco
Chevron
GET OUT AND PUSH!

this is apparently based on research one of his cousins that works for Shell has done in sampling gas from each company to determine additive content and levels, and "combustion quality". whatever that means.

just my $.02

Anthony

Da91Bird

I use 89 in my 305 TBI, all stock.


You guys might be interested in knowing that there are only a few petrolium companies producing the gasoline. Gas that's sold under the Quiktrip, Racetrac and other names is usually the same gas you might get at Texaco or Exxon, just with a different brand name. Stake out a distribution station some time. You'll see all different kinds of trucks from different companies pulling up and hauling away gas from the same big tank.

brharris27370

This toluene thing. I work at a chemical plant. How much toluene to add for more octane?

------------------
91 Camaro RS 5.0L Black Convertible 700R4. Owned 5 months bought from 1 owner girl. Working on that stock part.
** Added so far **
*GM Wonderbar
*Alston SFC

junkyarddog

87 anything,all this ******* gas is nice and raw,my dog loves it.

mtx28

hehehe

GTA-Force

I use 92 myself, it's the highest I can seem to get without going too far out of my way. :P

BTW, what does 76 gas fall under, and what's this "Amoco" I'm reading about?

Thanks!