More octane choices. Why?

[fantastic]

I doubt it's even e15 & probably just an extra option they could blend to that octane since they offered 91. It's just an extra option while they're at it? Are they're any vehicles that require it? I know my old Northstar said 91 I think & that was a 98' model year.

 

[Nessism1]

Rebel is a convenient store type place. 7-11 on steroids.

 

[tmorris1]

Ethanol Free is usually a blue handle, at least at my station.

Blue is E85 around here

 

[JJay03]

In my area 90 is ethanol free and its red at the pump. E85 is yellow.

 

[Jetronic]

How much difference can there really be when it’s only a point difference? I guess I need to read up on Octane some more.

Here (NC/SC/GA) we generally have 87, 89, 93. I figure a six point jump up from baseline 87 regular to 93 premium is worthwhile (generally +0.50 cents/gal) so I run it in the Cadillac Northstar V8 but the rest of the fleet lives on 87.

octane is a lot like HTHS, if it's high enough there's no benefit in more.. But it could be worthwile to check if you get ignition retard from knock through an obd scan tool and decide from there which octane rating is worth it.

 

[Pew]

How much difference can there really be when it’s only a point difference? I guess I need to read up on Octane some more.

Here (NC/SC/GA) we generally have 87, 89, 93. I figure a six point jump up from baseline 87 regular to 93 premium is worthwhile (generally +0.50 cents/gal) so I run it in the Cadillac Northstar V8 but the rest of the fleet lives on 87.

Not scientific, but we were able to run a few more degrees of timing across custom tunes with 93 when compared to 91 (assuming everything else is as similar as possible.) Difference averaged about 10-15hp.

 

[nthach]

octane is a lot like HTHS, if it's high enough there's no benefit in more.. But it could be worthwile to check if you get ignition retard from knock through an obd scan tool and decide from there which octane rating is worth it.

Yea, if the car isn’t tuned to take advantage of the higher octane it’s a wash.

And even with high octane, things aren’t equal. CA 91 being a E10 blend makes less power than “true” premium without EtOH. EtOH has less energy per gallon, so in effect blended gasoline has less BTUs per gallon vs. “straight” OH-free.

 

[k1xv]

The 90 octane fuel is for drivers who want to save 10 cents a gallon off of 91.

These stations do not have a separate storage tank for each octane grade it sells. They have a 87 tank, and a 91 tank. The pump itself blends these two fuels in the necessary proportion to produce the octane fuel selected.

If somebody's car runs fine on 91, they might want to try 90 to save 10 cents,