Is 93 Octane Really 93 Octane?

djspawn00 · January 6, 2008

With gas costing $3.50 a gallon in new york and my method of gauging my mileage of every tank I'm starting to believe more and more that many gas stations aren't really selling me the premium gas that I'm paying for. My scientific method may not be perfect but I try the best I can to keep things consistant. I'm just wondering if there is anyway to check the actual octane rating of the gas I'm buying and if anyone knows who's in charge of regulating this on Long Island and in NYC.

mburnickas · January 6, 2008

With gas costing $3.50 a gallon in new york and my method of gauging my mileage of every tank I'm starting to believe more and more that many gas stations aren't really selling me the premium gas that I'm paying for. My scientific method may not be perfect but I try the best I can to keep things consistant. I'm just wondering if there is anyway to check the actual octane rating of the gas I'm buying and if anyone knows who's in charge of regulating this on Long Island and in NYC.

Why are you using 93? I use FP+ or 131 in gas. It is unreal on the increase of MPG...

djspawn00 · January 8, 2008

With gas costing $3.50 a gallon in new york and my method of gauging my mileage of every tank I'm starting to believe more and more that many gas stations aren't really selling me the premium gas that I'm paying for. My scientific method may not be perfect but I try the best I can to keep things consistant. I'm just wondering if there is anyway to check the actual octane rating of the gas I'm buying and if anyone knows who's in charge of regulating this on Long Island and in NYC.

Why are you using 93? I use FP+ or 131 in gas. It is unreal on the increase of MPG...

fp+? 131? cmon you know I'm not good with the forum shorthand.

larful · January 9, 2008

With gas costing $3.50 a gallon in new york and my method of gauging my mileage of every tank I'm starting to believe more and more that many gas stations aren't really selling me the premium gas that I'm paying for. My scientific method may not be perfect but I try the best I can to keep things consistant. I'm just wondering if there is anyway to check the actual octane rating of the gas I'm buying and if anyone knows who's in charge of regulating this on Long Island and in NYC.

Why are you using 93? I use FP+ or 131 in gas. It is unreal on the increase of MPG...

fp+? 131? cmon you know I'm not good with the forum shorthand.

LOL What the hell is 131 is that Jet Fuel and how could the 131 save you on MPG When Im sure it costs more then 3.50 a gallon

jet_a_jockey · January 11, 2008

With gas costing $3.50 a gallon in new york and my method of gauging my mileage of every tank I'm starting to believe more and more that many gas stations aren't really selling me the premium gas that I'm paying for. My scientific method may not be perfect but I try the best I can to keep things consistant. I'm just wondering if there is anyway to check the actual octane rating of the gas I'm buying and if anyone knows who's in charge of regulating this on Long Island and in NYC.

Why are you using 93? I use FP+ or 131 in gas. It is unreal on the increase of MPG...

fp+? 131? cmon you know I'm not good with the forum shorthand.

LOL What the hell is 131 is that Jet Fuel and how could the 131 save you on MPG When Im sure it costs more then 3.50 a gallon

I can tell you the way it works here. Gas stations get fuel loads from whatever tanker company they have a contract with. Some are multi-compartment tanks, but most i've seen are single compartment. The multi-compartment tanks can have varying octanes or fuel types in them, so that a driver can deliver multiple fuel types/octanes in a trip. Anyhow, the driver is given a load by his dispatch, lets say, 93 octane. He loads it at the plant, and while at the plant the fuel is tested. then he takes it to the gas station. Once there he goes through a series of checks to make sure he's unloading in the proper tank etc. Theres no benefit for the driver to drop a load in the wrong tank (i.e. 87 into the 93), unless he had some kind of underhanded deal worked out with a gas station owner. Even then, there are quality control procedures that are in place in which the fuels are tested. I can't say for sure how often or whatever since I don't work at a gas station, but I do know they are in place. It would be safe to assume that the parent company of a gas station checks up on their stores from time to time.

I've heard people say 'oh i dont go there because they have water in the gas'. That is for the most part a myth. While it is true that water from moisture does collect in tanks over time, most tanks have a sump system that removes any water out of the tank. Also, the tanker truck that brings the fuel, when they receive it from the plant, it is filtered going into their truck. On many tank systems the fuel is then again filtered before it is pumped out. To add to that, they use a method of pumping that actually pulls from the top of the fuel, and any water contamination that may be in there is going to be at the very bottom, usually in a small space that does not ever get sucked up (unusable).

I believe that most people experience the changes in octane due to one reason. Time.

Unleaded gas loses its octane quickly, as opposed to leaded gasoline. The storage time on unleaded is much lower, i think the octane significantly degrades at around 6 months of storage but don't quote me on that.

So if you want consistency in your octane, the best thing is to go to stations you are familiar with and you know that they go through alot of fuel.

As far as gas mileage increases vs octane ratings goes. Thats for the most part a myth also. The only benefit of higher octane gas is that a more advanced timing curve can be applied by the computer. This benefit is marginal unless you are running a high compression or high performance engine (forced induction especially).

With newer computer controlled cars, if they require a high octane gas, it is best to use it. If you end up putting 87 in a car that requires 93, the result can be engine preignition, which is when the fuel combusts from heat rather than spark. I believe this is due to the lower flash point of lower octane fuel. Anyhow, the cars computer normally can deal with this, and will !Removed! the timing to avoid the dreaded "spark knock". The result of constantly using low grade gas in an engine that requires higher grade is a loss of performance from the timing changes, and possible long term damage/wear from preignition.