i usually use plus in my car because i know its sopposedly better for your car but i never notice a difference between plus and regular. the car has 130k on it and everything works really good. clean spark plugs and the oil too. so i figured if i wanna keep it that way i should stick with plus. but ive changed it every now and then to regular when i really dont have any money. what do u guys use? do u think it makes a difference in how long your car will last?

 

Your car will probably have a knock sensor, meaning you can run any grade of fuel without hurting the engine at all!
I suggest running the grade where the car drives as smooth as possible for your taste!

 

low octane regular.

because you DONT get any more power out of premium.. or anything else for that matter (other then a lighter wallet)


your car is designed to run on regular.. im not going to retype the whole speel again, but trust me, you arnt gaining anything, or losing anything, do a search.

 

An engine designed to run on 87 octane fuel (which all of ours are to my knowledge, save the TTA) will run better on 87 octane fuel. Period. Unless you've advanced the ignition timing *way* beyond stock specification. Better fuel economy and more power from a complete burn.

A good example of when to use premium fuels, other than in cars designed to run on them, is my '86, for instance. 5 lbs of boost, no changes to ignition timing. Running 91 octane as a saftey net against detonation under boost.

 

If your local Sunoco or other station still sells 86 for a penny less, buy it.

87.3 is the lowest it gets. They can't make it any lower. It flow from the tap at 87.3
But Sunoco plays that marketing trick.
Cheap people still get the same gas cheap, then other that fall for the mind game pay a penny or two more for the same thing.


But in all honesty. I use to get the best mileage when I ran ultra94 but I did lots of E-way driving.

 

I usally ran 89.Should I switch to 87?

 

yes.

 

I have awalys used 91 since the day i bought my car and for the extra 5 cents a gallon at costco im not too concerned and my car has awlays ran great and gotten good mpg

 

http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

I used to believe the whole "more octane means more power" too back when I was 16 and stupid. If you don't ping with 87, that's the BEST to use.

 

whatever is the cheapest I can find when I get to 200miles a tank.

 

I use premium, there is no difference in the gas cost, in winter time it starts right up.

 

What is the difference between winter gas and the gas they use in the summer. SIne they switched i have benn getting worse gas milage at first i thoght it was me but then my G/F started saying the same thing that her milage is way down.

 

Google my man....Google. http://zhome.com/ZCMnL/PICS/winterGas/winterGas.html

 

The third generation F-car V6 engines don't have a knock sensor, only the V8's. Since a lot of you guys have high mileage engines, start with 87 regular as described in the owners manual, and work your way up to whatever octane you need to prevent engine knock. Remember octane is just a measure of the fuels ability to delay exploding in the combustion chamber. Low octane gas explodes more quickly, and high octane explodes more slowly. High octane will do nothing to increase power in an engine whose timing, and compression ratio are not set to take advantage of it.

 

Yes we do have knock sensors because i replaced mine on my 3.1.

 

Are you sure they didn't add it on later years? My '87 2.8L doesn't have one. I've replaced all the sensors on my car over the last few months, and I don't have any unused connectors on the harness or unidentified sensors. GM calls it a detonation sensor, the GM service manual for '87 doesn't show it either, only on the V8 engines.

 

Mass Airflow, no knock sensor.
Speed Density, knock sensor.
Simple.

 

Thank You! That does make it simple. (I have no experience with the speed density system or newer cars.)

To get back on topic...

I use 87 octane.

 

I use 93, or 100. Does anyone really want to argue that I should be running 87 or lower?

 

cool, thanx. i hear so many rumors and all u know? i know the plus didnt help my performance at all, i just figured it ran better so its probably cleaner u know? those web sites are pretty helpful. i'll stick with regular. and about the knocking, mine sounds like it has a tapping lifter when i first start it on cold mornings. sometimes a squeeky belt 2. but it goes away. anyone else heard of this?

 

My stock '87 MAF engine has a knock sensor.

 

You're gonna have to prove that with pictures....

 

Probably a tapping lifter. Usually the first sign of an aging hydraulic lifter is a start-up tap while the lifter is pumping up.

 

my 88 has a spot for a knock sensor, lol.

(3.4)

 

I usually use 89. I feel like it may run cleaner or something.. Maybe I should switch to 87...

 

You are right, I don't have a knock sensor. Went out to check and realized I was confusing this car engine with a 4.3 I rebuilt not long ago.

 

I use premo, the regular gas in Maine sucks so bad it is the crap from the bottem of the tank. It looks like **** some times and smells wrank some times, not like gas like bad gas.
At least premo gas is consistant.
I run premo plus a 1pint bottle of methanol to 8-10gal's, it cost's more but keeps the detonation down on the interstate and going up hills at high speeds.
91 or premo costs more but some older cars get better gas mileage with it, not all. The only way to know for sure is to test it on your car.

 

Here in Las Vegas most of the gass in the stations comes into town thru a pipeline from California. Thats diesel, gasoline, jetfuel, and anything else. Some of the stations get the cheapest gas that is a blend of the buffer zones brought up to the octane rating.

I quit using 87 octane because it smelled like diesel.

 

Werd. My 3.4 already ahs higher compression than the 3.1/2.8, and I never know when I'm gonna use the juice, so i usually put in 93, but only if the bottle is in the car, otherwise it's 87.

 

I've been told that 89 is a "cleaner" gas... and that people should run that normally, then every 6 tanks, use 93... dunno about that... a mechanic that specializes in rebuilding motors told me he does this with all his cars... and one thing to note: he's gotta be the worst rebuilder ever... at least he fixed his mistakes for free...

 

Bahhh, last sunday I full the tank up with regular gas......now every time I start the car, it smells like gasoline....for me there is no difference between the regular and premium or supreme or whatever you want to call the expensiest one.....I am gonna come back to the premium gas.....

 

I've heard that it is not a good thing to switch between fuel grades... that if you start with 87 to stay with 87 and if you started with the premium to stay with the premium. I was hoping to find out from someone what the actual manufacturer suggested fuel grade is... is it 87, anyone know for sure?

 

87 owner's manual says 87 octane... 89-91 for one of the V8s, but I couldn't tell you which one.

I was taught that the difference between grades was the burn rate... Higher the octane, the slower the burn rate. Which is why Doward above, project89, and others with power adders generally run higher octane gas, to prevent detonation with increased combustion temps and pressures. Since the price differences between octanes here in NY is so ridiculous, I'm going to be tuning my MegaSquirt to use 87 (10 cent difference between grades starting around $3.70 per gallon as I post this) with the increase in compression due to the FWD head swap.

 

I put in 5 gallons of 91 in my car after I swapped out the fuel pump. The reason? 91 octane at our local gas station is non-oxygenated. All killer no filler. I didn't want to screw up my car as soon as it started for the first time in a while by introducing bad gas into the system right away.

 

I run 93, for some reason my MPG is significantly better.

 

i run 89 octane E-10 for the street, 93 on the dyno and at the track because i run a few more degrees in PE and in Launch mode.



Maverick H1L is correct, higher octane gas has a slower burn rate. It's for cars with high compression, boost or nitrous or any time where preignition would become an issue. The myths around gas grades have been around forever, use what the manual says to use.. or if you have a built engine use common sense.

 

I use non-Ethanol regular grade fuel.