Octane Question

[03NHVW]

OK, this probably has been discussed before so I'm guessing the answer is right there in front of me, but here goes;
Can different octanes of gas be mixed?
My VDub actually runs best on 91.
My most convenient stations sell 91 and 93, both for the same $$$.
What if I mixed Station B's 93 and 89 octane for an average of 91? and a cheaper overall tank? Is that useable or do they not mix?

Also, I know that the savings are hardly worth the time it would take to make two separate transactions, but still I've been considering it.
Thanks!

[busypaws]

yes mix away. I suspect that the 93 octane for the same price of the 91 octane is because the 93 has ethanol and the 91 is pure gas. Lots of other threads here discussing pros/cons of 10% ethanol mixture vs. pure gas. Search away.

[03NHVW]

Thanks for replying busypaws.
If I'm not mistaken (and I could be), I believe neither is pure gas.

I don't know if you're familiar but the 91 station is Irving and the 93 is Mobil (if it makes a difference). My feeling is that since the car only "needs" 91 I typically hit the Irving, but I like to get gas in the morning and that station is on the opposite side of the highway, causing me a few minutes of idle time while I wait for traffic to pass while I'm pulling in/out. In their favor, their employees are nicer though.

[mcrews]

yep you can mix.

[MPGranger]

It is my understanding that gas stations have two master gas tanks, even though they offer three grades. So the middle gas grade is actually a mix of the lower master and the higher master already.

Also Mobil is a Top Tier Gasoline station. Top Tier is a nonGovernment regulated fuel additive initiative, they claim there gas additives are better than generic gas. I haven't seen any independent testing, to say yea or nay on the subject; but that is why the top tier gas stations will typically be more expensive than normal.

[Old Tele man]

...more "Top Tier" info here: Top Tier Gasoline