tranceemotionz

I was just curious to know what exact fuel grade i should be putting in my car.... 91 z28 stock? sorry for the stupid question.

ScottyRS

iTrader: (2)

My '92 owner's manual says TPI cars use 91+ octane.

master486

How about an 87 5.0 TPI? I've been using 87 (as a struggling college student I can't afford too much).

Mkos1980

iTrader: (8)

my 89 manual states 87* for all engines including TPI

freestylzz

SOme of us use C16.

fire350tpi

my car loves premium(93), its what i try to use

rik89gta

87 works just fine for my L98

chevy boi

i switch from 87 and 91 when i fill up and i also fill up at half tank, its not so painfull on my wallet

ntomsheck

iTrader: (1)

Normally premium is only 10-20 cents more per gallon so even if you have a 20 gallon tank it only takes 2-4 more dollars to fill it up. My tank size is only 12 gallons from E-F so it only costs 1.20-2.40 more to fill it up with premium as opposed to regular. Just thought I'd point that out.

sicc87

yuuupp my L98 loves premium.. although premium here in CA is 91 octane..

G-Ride14

CA gas sucks

91greenbird

iTrader: (4)

i use 93 but my timing is set 4 degrees more in advance then stock.

3rdgenZ

iTrader: (1)

reg will do fine. the only draw back is performance loss.

dave-92gta

iTrader: (1)

i grab the best i can get, which is 91 here in canada...does fine, but i think your suposed to put 91, because it has a higher conpresion ration... i think its like 9.3, so its best to put 91 or 93 for you american drivers, its cleenest, and by the way, 91 or 93 does not give more power, its makes ther engine run cleaner, and in a sence makes it stronger, but not faster.

Demon355

iTrader: (1)

I've ran ultra 94 in my 305 a few times, didn't really notice anything. But for the most part I just ran 87. For my new 355 I think I'll use 91 or at least medium grade.

LT1FUN

My L98 gets vastly better milage using Sunoco 94 as opposed to regular octane or even premium 91.

I'm not imagining it either. I've seen what an average 2mpg increase using 94 octane (so long as I'm driving responsibly).

Also, since I advanced the timing on the car aswell, the 94 does a good job at preventing detonation. 92 is alright aswell, but anything less, and I get engine knock, so I don't really have a choice in the matter

MAD_IROC-Z_85

Here in Quebec gas is cheap, 91 is the top in octane, I have to run on Lucas Octane booster 1 bottle in an half tank or put 50/50 of super whit 100LL(plane fuel), but the plane fuel is about 1.92$/liter!!!

So please don’t tell me it cost tow much to put premium gas in your V8!!

Come on!!!

At least, relaxe on gaz pedal!!

Mkos1980

iTrader: (8)

I'd love to see some dyno graphs of people claiming they feel more power with higher octane. If your stock timing is at 6* the octane in the manual whether is be 87 or 91 should be sufficiant. I think most of it is a head game. Car Craft did a report one issue with a stang and the higher the octane the less power it made , unless they cranked the timing up. I think it was 0* with 87 made like 300 HP and then they used 94 octane and made 288. They had to move the timing up a few degrees to like 8 to achieve the 300 again.

3rdgenZ

iTrader: (1)

octane is just the rating of fast the fuel burns.
so in a high comp motor running low octane can cause spark knock, which in a efi motor the knock sen. reads and retards the timeing making less power.
now a stock L98 is not a high comp motor at 9-9.5 to one. so there is little diff between the two. how "clean" your motor is depends on wheither you use Shell or 711 gas. most high-end gas manuf. put detrugence in the gas which will clean your motor.

the idea is to go as low as possible with your octane and still be in the limits of your comp. in other words without making knock.

MAD_IROC-Z_85

I ear that you can get some point octane by mixing different brand of fuel because :

Fuel Octane = (Research Octane+Motor octane)/2 , then exemple: sunoco can have 96(R.O.)+92(M.O.)=94 real octane



And a

What is the Highest Octane fuel avaible at the pump in your contry and what is the price!! ??

Here Super(91) is now at 1.28$/litre today

Thanks

dave-92gta

iTrader: (1)

i live in winnipeg canada, its $1.28/litre. question then, if i use 91 octane, what timing should i use to get the most preformance out of a stock L98?

MAD_IROC-Z_85

If your motor does'nt knock on high load at and on WOT your maybe able to give em a little more

Try it in third gear at 50km(about 1500rpm) you should be able to do a WOT whitout any knoking, if you ear some , well release pedal and retard your timming a little bit

91 octane should be enough for you'r engine some time carbon accumulation and other does'nt help but,...

And for your timing it depend on your gear, transmission, torque, but the stock timing for your car is about 4-6 at idle, but you can jump to 8-10 by doing some road test it should give you more power!!

I hope my english is not to bad, I just do my best!!! ( but I don't care )

Nixon1

It's amazing how many people just don't know what octane is all about...

Run the lowest possible without detonation. You will make more power, and the motor will run cleaner. YES, CLEANER. Higher octane is more resistant to spontaneous detonation, but as a side-effect, is also slower-burning. Meaning, running higher octane than your motor requires, can result in an incomplete combustion because the fuel just hasn't had enough time in the chamber to fully burn. This results in carbon buildup on the pistons and valves, which can lead to other issues down the road, including creating a "dependence" on that octane in extreme cases, because the buildup has effectively increased the compression ratio on the cylinder.

If you want to run higher octane, you need to advance your ignition timing. Why? It sparks earlier obviously, and you're giving the combustion event more time before the cycle ends.

My motor will run on 87 octane all day, but I choose to run it on 93 and advance the ignition timing to 15 degrees base (stock is 10.) Makes more power this way, and it can only handle another degree before it starts to ping so it's in the perfect zone.

3rdgenZ

iTrader: (1)

[quote=Nixon1;3020844]It's amazing how many people just don't know what octane is all about...


nobody here is disputing your statements, so why would you make such a bold statement?

Nixon1

[QUOTE=3rdgenZ;3021094]
Dont take it all personally now.

Im just saying, in my experience, the amount of people who know about cars but are ignorant about octane is amazingly high.

tranceemotionz

Ive been using 93 about 99 percent of the time since ive had my l98 (since feb. of this year) and recently took a trip and got about 180 on a tank. I use the i think its 87 octane?, and got around 250 miles on that tank so thats why i asked the octane question.

MAD_IROC-Z_85

You may see a little difference in consuption but I mostly think that is much more the way you have driven those 180 WOT milles

qube

I'm not sure what scale they use in the US (RON or MON?)

UK gas is rated at 95 Octane (RON) / 85 (MON) and typically costs £0.97/Ltr or $7/Gallon!

You can buy 102 Octane (RON) gas but it costs a fortune:

BP Ultimate UK - 102 octane

MAD_IROC-Z_85

It is a standard :

95 (RON) + 85 (MON)
__________________ = 90 octane!!!
2

Look at :

Octane Information Calculator

qube

Ah, cheers for that, the scale used is called PON.

I'm running it at the stock 6 degrees, looks like I should be able to run it a little higher.

Matthew

Tremo

I use 91 in my 88 LB9. Never a hint of pinging.

85IrocZ-28

I run the cheap stuff in my TPI, 85 octane. No major mods, just flowmaster and K&N to breathe a little better. I do live at a fairly high elevation though, Utah. It seems to run just fine. There is no difference if I run premium, so I stick with the 85 octane.

IROZINCO

iTrader: (1)

Same as above - i'm in Colorado - i have an 87 350TPI with about 130k on it - 85 is regular here - 91 is top of the line - i run 85 with no problems at all.

Ted Rooney

The computer controls the gas the manual says computer is set for 87 octain so put in 91 will not make a diff on power jest cleaner engine

Heatzone25

Owner's manual states 91+ octane, however, car will run on lower octane at slightly reduced performance. That is straight from the manual. Also, that is part of the reason our cars have a knock sensor.