trexbob

iTrader: (1)

Don't some of the 98's have an issue where the knock sensors are overly sensitive, therefore the car may actually be running on the low octane maps regardless of what octane is put in the car? This would explain how some people see no difference in the grades of gas. But how would you test it..... ? Does a knock sensor register on an obd-2 scanner?

scottso

Just so we are all clear - this is a direct quote from the 2000 Camaro owners manual -

"If you have the 5.7L V8 engine (VIN Code G), use premium unleaded gasoline rated at 91 octane or higher for best performance. You may use middle grade or regular unleaded gasolines, but your vehicle’s acceleration may be slightly reduced."

Is my acceleration slightly reduced - according to this yes.

Another quote same manual...

"...don’t worry if you hear a little pinging noise when you’re accelerating or driving up a hill. That’s normal, and you don’t have to buy a higher octane fuel to get rid of pinging. It’s the heavy, constant knock that means you have a problem."

Very straight forward. There is no magic. 87 octane pulls some timing - plain and simple. If you are not knocking - you are not doing damage.

For me - I don't need performance "on the edge". I am perfectly happy not being the first one away from the stoplight most of the time. I have a daily driver.

Still want to call me a cheap ***? OK. But please don't say that it is causing damage to the motor - cause GM says otherwise.

pro2low

iTrader: (3)

i feel bad when i put 92 into my car lol if i doo i go buy some 100 too! im kinda weird when it comes to my car though.

Mr Incredible

I fully understand Meent's meaning. It's pretty much the same as yours. But, I re-repeat, "Yeah...And?"

I have a CRX now for the winter. 40mpg for $875. It beats 10mpg in the V10 F250SuperDuty.

But, SpeedRacer in NC, if you want to drive like an idiot all the time...if it makes you feel like SomeBody special, well fine, go right ahead. Some of us, however, are grownups now and don't feel like they have to be that way all the time.

Castratikon

My question to people that use 87 is do you actually get the same mileage out of 87 as 93? I certainly didn't and it cost more in the end to put 87 in. Even if I wanted to use 87 in mine, theres nothing but disadvantage to me and my car. Less mpg and less power that costs me more in the end. I'm not flaming or anything, I'm just curious if you get the same mileage in your cars using 87 as opposed to 93.

LordOfChaos

iTrader: (3)

i lost about 1mpg using 87 over 93 before i had my tune. so overall it did save me money

cant even consider using 87 now tho :-(

b0pric01

iTrader: (5)

i was considering this. it is winter now but since my car is my dd I have to drive it. Its too cold out and usually too wet out to drive it hard anyhow so I might as well use 87 b/c I am flat broke. I figure I'll just watch the rpms, grandpa shift, and it should be fine. Lets see, its like 20 cents more per gallon and the tank is like, 16 gallons or so. Fill up on 87 saves me 3.20. So at the current rate of fuel pricing, every 13-16 fill ups i get one free! wow, those savings kinda suck. Oh well, it is winter.

scottso

An interesting question. I'm only working on my second tankful with the 2000 I just got. I reset the ODO and do the mental math pretty much every time I fill up. First tank worked out to about 16.5mpg. That is almost all around town - in NJ that means traffic lights and stop signs until you . So that's pretty good for here. The '96 did a little worse.

I will have to find out if super improves it once I establish a baseline.

NDFORSPD

BINGO buddy, hit it on the head, the 91+ will burn CLEANER AND FULLER(thats the true meanin of octane) thereby giving slightly better mpgs vs. the lower grade. So in essense, why would you fill up with a lower octane gas that MIGHT(key word) damage your engine over the longhaul and NOT save any money(comparing money spent at the pump vs. real world mpgs). Makes no sense to me!.......and yes 87 will burn quicker than 91.....just another question, how much does a crate LS1 cost

scottso

Not the way I understand it. Octane is the fuel's resistance to detonating at a given compression. That's why higher octane fuel in an engine that does not require it is no benefit. There is no more energy in 87 than there is in 93, or 100 octane for that matter - it just resists ignition from compression better. It does not burn cleaner - it just has less of a propensity toward exploding under compression - which is knocking or pinging. Putting 93 in an engine designed for 87 could, in theory, cause the fuel not to burn completely because of this resistance - producing (again in theory) less power.

Now with that said - yes it is recommended because of the motor's compression ratio. As stated above, these things considered the mileage factor may just offset the cost. But... because of the computer's ability to pull timing to compensate - in the absence of knock - no harm no foul.

Mr Incredible

It does turn out to be almost a wash, but the 87 worked out a tad better for costs. I got a tiny bit less mpgs from 87 compared to 91.

But 87 isn't going to harm your engine if you put it in and drive like a normal person.

The key phrase being, "Not like a NASCAR wanna-be."

98TADRIVER

iTrader: (36)

i left out one small detail, you cant run it at WOT and expect it to run good, it will ping like a **** and thats not good. I made the mistake of not watching the gas station attendent and he put 87 in my car. It ran fine on the way to philly, since i was in 6th gear the whole time @ 2k rpm. but the next day when i was coming home and jumped on it while merging onto the highway, it was pinging horribly. what a bad sound that metallic rapping is, also known as spark knock.

JJhomer83

My car is not a daily driver for me so I only put in 93. From personal experience with many vehicles while driving them to and from work I get the best bang for the buck with 89 octane.

speedshifterNC

iTrader: (1)

good thing I'm not a moderator or this thread would have been over long ago...too much bs

Websy21

iTrader: (34)

lol, now thats funny, but not really. Pretty much sums it up in a nutshell though

scottso

You coming back to read it though....

Chase22

iTrader: (1)

After about 10 gallons of 87, I got about 17.8 mpg compared to around 18 with 93. But the acceleration did suck. I figure I will just put 93 unless im really low on money.

TheSilverOne

iTrader: (22)

if you can't afford premium fuel then sell the car and get a 4cyl.

Jakester136

My 98 z is still pretty much stock, I run 87 all the time and have no knock or performance loss at all. I do get a few more mpg when i run 94 however..or shell v-power. v-power smells funny when I use it thought. I wonder why???

vettehardt

iTrader: (1)

Octane is the fuels resistance to knock. The higher the number, the more resistance. Every engine is designed to run on a certain octane fuel. Our LS1's were designed for 91-93, but have the advantage of tuning to be able to run lesser octane fuels. High compression motors need the high octane. Stock motors are able to run on 87 without causing signifigant damage. Generally, the higher octane fuels are cleaner (that is why they sell at a Premium price) and will promote better fuel combustion.

Always look to your owners manual to se what the "recomended" octane fuel is for your car. Just because it is redomended, doesn't mean that is all you have to put into the car. My sister has a chrysler sebring designed for 87. She recently switched to 89 due to getting better milage out of it. It was enought to offset the cost differance.

Me? I always run 92-94 in my camaro because that is what the motor was designed for. If i ever have to put 87 into it, I will not be worried about damaging the motor.