What Grade of Gasoline do you use

[doublejager2000]

look at this its perfect to explain.and save you a few bucks http://theserviceadvisor.com/octane.htm
Most cars are designed to burn regular unleaded fuels with an octane rating of 87. If the vehicle needs a higher octane rating of 89-93, there is documentation in the owner’s manual, as well as possibly under the fuel gauge and by the fuel fill hole. Usually you will see this rating for high performance engines only.
WHAT IF I PREFER TO USE GASOLINE WITH HIGHER OCTANE RATINGS?
You can, but there are no real benefits, other than the gasoline manufacturers making more money off of you. When you use a fuel with a higher octane rating than your vehicle requires, you can send this unburned fuel into the emissions system. It can also collect in the catalytic converter. When you over stress any system, it can malfunction or not do what it was designed to do properly. In the early 90's, an early warning symptom was a rotten egg smell from the tailpipe. Easy fix, go back to using regular 87 octane gasoline. The rude odor usually disappears after several tanks of gasoline.

[doublejager2000]

found this too>>>>
The only time you might need to switch to a higher octane level is if your car engine knocks when you use the recommended fuel. This happens to a small percentage of cars.
Unless your engine is knocking, buying higher octane gasoline is a waste of money, too. Premium gas costs 15 to 20 cents per gallon more than regular. That can add up to $100 or more a year in extra costs. Studies indicate that altogether, drivers may be spending hundreds of millions of dollars each year for higher octane gas than they need.
http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

[Roger Oakley]

I run, what we call Unleaded, I think you guys call it Regular?
And now the price difference. A gallon of Unleaded over is about £4.30 GBP which works out to be about $8.20 USD a gallon.

Roger

[tunatussle]

Beth & Rod, Do you have to deal with ethenol in your gas yet? We are on E-10.

[Deck Guy]

Most people must have slept through this part of chemistry class.

Higher octane fuels are actually less explosive, which is why they don't pre-ignite in your cylinders under higher compression. They allow higher compression without pre-ignition or spark-knock. They are not more pure or cleaner. If you do not have issues with pre-ignition using 87 octane, it's like burning dollar bills if you're feeding your engine premium. Wouldn't you think the engineers who designed the engines would make their recommendations for the fuel that ran most efficiently?

Airplane gas or Avgas, (not jet fuel) is 100 octane, but Low Lead. You can buy it at any airport for around $3.00 a gallon, but don't call me when you burn your pistons up! Jet fuel is basically kerosene.

BTW, I burn 87 in my equipment ant 93 in my truck (Supercharged=high compression). I do get spark knock with any lower octane.

[PA Dutchman]

Nice to know that about jet fuel...kerosene....ITS obscene how they use "fuel" costs as a reason to charge for for stuff. Like trash companies, I'm sure they pay 'consumer price' for their fuel station at their HQ.

Just read something yesterday about another 12cents being added to our fuel tax at the pump...for "mass transit"...if your riding the bus, taking a train dailly you are not filling up a car, probably don't own a car.

actually I voted on this and from now on....I'm taking larry's advice. cheapest pump I find.

[PLD]

Originally Posted by Deck Guy

Airplane gas or Avgas, (not jet fuel) is 100 octane, but Low Lead. You can buy it at any airport for around $3.00 a gallon, but don't call me when you burn your pistons up! Jet fuel is basically kerosene.

Correction:
AvGas is high octane, low vapor point gasoline. It can be burned in your gas powered car, but can cause a fire or explode in your burner. AvGas does contain lead, so it is illegal use on road and can reap havock on your catalytic converter.

Jet Fuel or Jet-A is highly refined kerosene blend. It can be burned in your burner, but not in your car.

[Doug Dahlke]

I use 87 octane in the truck and my power washer. 18 HP Kohler Command 2 cylinder engine. I use kerosene in the burner. I've heard about the fuel pump issues but that is how it was set up when I got it so I continue to use it. The machine still has low hours on it. If there is a problem I'll make the switch to diesel.

[plainpainter]

Larry Davis commented that higher octane fuels are less explosive - he is right, lower octane fuels have more chemical potential energy than higher octane fuels. If you put a high octane fuel in an engine with a relatively low compression ratio - you will get carbon deposits. You need a certain amount of heat in a cylinder to burn off deposits. You can see this for yourself - look at your plugs with the lower octane fuels - it should be golden brown at premium burning. If you switch to a higher octane - the spark plug will turn black - this indicates cooler conditions in the chamber. Always run the lowest octane fuel you can before conditions of ping happen. Your engine will give you better performance. Higher compression ratios are supplying the heat - so your fuel doesnt need to be as explosive, a,k,a, higher octane.

[MMI Enterprises]

Guess someone did the poll and is why this thread came up again. I'll comment...

Higher octane adds no power for normal/lower compression engines. If anything the regular has more potential than higher octane. When you get into higher compression ratios the higher octane can result in more torque and horsepower though due to extended burn it offers. Make no mistake the extra power comes really from the higher compression such engines offers. Running as low a octane that your stock/low compression engine will tolerate without knock and ping is ideal to acheive most bang for your buck.