I remember reading in here, somewhere, a thread about what brand of gas to use and how much octane is necessary.

A few mentioned that they used Sunoco Premium 94, but I don't recall where they were located.

We have Sunoco stations here in Florida, but the rating on their premium is 93 octane.

HOWEVER....

They do sell 100 octane "racing fuel," at about $4.43 per gallon. Doin' a little math, I figured out that if I put in 12 gallons of 93 octane and 2 gallons of 100 octane, that I would get 14 gallons of 94 octane.

I did it, and my car loves it. :-)

Actually, the real reason I did it was because it seemed like my car had been knocking after my last fillup -- which was pretty good gas (BP) and of 93 octane.

After feeding my I30 some 94 octane joy juice, the knock stopped.

Did I get a batch of bad BP gas?

What are the chances that an unscrupulous dealer dumped some lower grade petrol into the premium tanks???

Many years ago (1987 to be exact), I had a dinky Toyota Tercel that was supposed to run on regular. I had the car for nearly 150,000 miles and it ALWAYS knocked on regular!

The moral of the story is "Use whatever gas makes your car happy."

 

Your car is designed to run on 91 octane, using anything higher is a waste of money unless your boosted.

If you have excessive knock and ping you probably have a build up of carbon deposits. Have your intake and fuel injection cleaned by a professional. A malfunctioning EGR system can also cause ping.

 

And don't be afraid to replace your spark plugs, fuel filter and air filter if required.

 

All of the above has been done.

The octane ranges we have here are 87, 89, and 93 -- there is no 91. Obviously, 89 is too low, so I have to use 93 octane.

Like I said, I suspect a bad batch since I never had any problems with premium before and my car runs just fine on it.

People spend thousands of dollars on their cars to get them to run faster, and a lot of owners will tell you that their cars flat out run better on 93 octane than 91 octane.

So, what's the cost savings between the two? Like 90 cents a tankful?

Maybe I should try creating a batch of 91 octane by combining 9 gallons of 93 octane with 9 gallons of 87 octane...to see if you are correct; i..e, that my car can run on the octane that the manufacturer specifies.

On the other hand, after my experience with the Tercel, I tend to disbelieve what car companies recommend.

 

I agree. But before paying big bucks for a professional to clean the intake and fuel injectors, I would try a bottle of Techron in your tank. That is frequently all that is needed to clean the system.

As for 100 Octane Racing Fuel. This is not the same octane rating as the 93 (R+M)/2 octane you buy at your local gas station -- so you can't average 100 and 93 and get anything meaningful. The 100 Octane is Research Octane (RON) and is a different measure. This racing fuel probably has an (R+M)/2 octane rating of from 94 to 95. For more information, see my postings on this thread:
http://forums.maxima.org/showthread.php?t=396716

 

The phrase "placebo effect" comes to mind.

 

I wouldnt be shocked at all to hear a dealer was putting regular in the premium tank.

 

I would be. Most states (not the Federal Govt) test gas stations from time to time. They check to be certain that the pumps are accurately measuring the fuel and that the fuel meets the specifications posted on the pump. If not, the station is fined. I believe each state has a range that they consider allowable, so (for example) a tested 90.7 octane may be acceptable as a 91 octane posting. These tests are not very frequent, but the do happen and there are penalties for failure. There is no penalty for "giving away octane" or volume (1.025 gallons for a measured gallon would be volume give-away).

 

yes but the key phrase is from time to time, if they just had somone in who checked the pumps and the next day the truck pulls up, i could see the owner having them fill up both tanks with 87 or one with 87 and one with 89, but no 91 or 93.

 

Most stations only have 2 tanks in the ground. One for premium and one for regular. The mid is mixed by the pump. Here in my area, we have 87, 89, and 93. To get 89, the pump pumps 2 gallons (or units) of 87 to 1 of 93. Anyway, most stations wouldn't be able to dictate what went into the tanks because the gas companies put the gas in, service the pumps, etc and the owner simply sells the gas. That's not to say that there aren't some out there that are out to screw you because there are.

And the States generally check the accuracy of octane and amount every so often (its not annually, I can tell you that!). But you are dead on when you say that they sometimes don't give you what you pay for. I have had several examples (and more in the past couple of years since gas has gotten more expensive for some reason) of pumps dispensing less gas than they read.

Generally, you can tell by the smell of the gasoline if it is premium, at least I've always been able to. Premium smells "sweeter" than does regular, which has a sulfury smell to me. That's what I've noticed over my tenure of buying gasoline, at least.

And, I've gotten gas with water in it a couple of times. Its not the best thing in the world and generally acts as if it is missing if its not got a lot of water in it. If its got a lot, it will simply die. It will generally only knock if the gas is a lower octane than recommended or if the car is not running properly to begin with. Either one can be thought of as "bad gas" since each will cause the car not to run properly.

Oh well, my thoughts.

 

Check this thread about octane at the pump. Not very reassuring. I'm sure it happens in many other states....

premium octane

 

The city official charged with keeping pumps inline in Cranston RI went on vacation for two years and never checked one. A Couple of the stations thought it strange but never said anything cuz they thought the were making out... Uh uh, Nope... News channel found that 95% of the stations were giving gas away hahahaha... serves them right greedy punks....

 

Thanks for the article. I feel vindicated!

I guess I wasn't crazy after all when I started this thread and wrote that I got a batch of bad gas that caused my engine to knock.

 

Yes, there are crooks in all businesses. You should not be surprised. This is one reason that many people have cut back buying from the small business person -- more likely to be able to cheat you. The big firms like Wal-Mart know that if they cheat you, it could damage their reputation in a very wide area of the country. They know that in the long-term cheating the customer is bad for business. More small business people need to also wise-up.

 

yeah..... yeah.. and this one time at bandcamp

 

"FSSB?" What's that? A "Front Strut Sushi Bar?"