Octane-How do you know?

[XtraRevsSurely]

When you go to a gas station and select your octane (here is 87/89/93) and there is only 1 pump, are you truely getting what you select?

Many stations have 1 pump for each octane rating so I feel more confident I'm getting what I want. When all 3 ratings use the same pump am I just paying more for the same stuff? It seems like if gas stations were going to be shady that would be the first place. Unless there is often regulation!

Are there different storeage tanks for Regluar-Mid-Premium at stations? I thought about this because it seems that when fuel is delivered by tanker trucks it all comes in the same tanker. Unless there are separate deliveries for each grade.

I've always used 93 octane in my car because that's what is recommended for the 2zz-ge. Blindly, I assume I'm getting what I pay for.

[MR2Jedi]

Yes, they have 3 tanks in the ground and you're getting what ever button you pushed. I use '95 octane in my MR2. If it wasn't at least '93, it would knock like crazy.

[TrailDust]

There's also the aspect of government oversight, albeit dependent on the state you live in I suppose. In California, pumps at stations are inspected each year and authenticated that they function properly. To even accidentally dispense product in a manner not prescribed is a major issue and not something a gas station owner takes lightly. Short of it is (in California at least) you can have an extremely high degree of confidence that the gas being dispensed to you is not only the correct grade but that the pump is dispensing the proper amount of product into your tank versus what the pump says it's dispensing into your tank.

[projektvertx]

[QUOTE=MR2Jedi;3763074]Yes, they have 3 tanks in the ground and you're getting what ever button you pushed.QUOTE]

Dead on the money sir.

Next time you're at the station, note that there are multiple nozzles for the tanker to unload at. Unless the tanker mixes up and the owner of the station truly doesn't care, I doubt you're getting the wrong product. Realistically though, you have no way of verifying it at the pump, other than blind faith, and assuming that the station doesn't tamper with the pump between inspections.

[FromBMWtoEcho]

From my understanding there are only two tanks in the ground. One for 87 octane and one for 91 octane and the mixing for medium grade is done at the pump.