i have seen 91. but its stupid. imo.

 

Price wise and if 91 delivers close to the same performance as the 93 it could be well worth it. At my local filling station I'm going to be the same additional cents per gallon jumping from 87 to 91 as I would from 91 to 93. If things work in a linear fashion the 91 becomes the best cost/value.

 

Iv'e had installed for 2 weeks now...I have the 91 setting...In my
mind huge difference...Higher RPM and way stiffer shifts...My opinion
definetly worth it...

 

Here, you have the choice of 87, 89, or 93.

 

I guess I should quantify my statement a bit as close to home I have 87, 89, 91, 93 and '94 octane fuels available. So I guess I'm OK with whatever I need to run. I also wouldn't be opposed to mixing two fuels at the pump as it's something I need to do for my Chevelle on a regular basis or make a 30 mile trip to purchase unleaded 100 Octane.

 

Honest question.
You guys reckon one 93 is the same as the next, or is there a difference in Amoco vs Shell, or whoever vs whoever?
I've got 93 and 91 both available right up on the corner across the street from each other, and have found no significant advantage with the 93 which is more expensive, in the Jeep with AEM CAI, Flashpaq, & Volant exhaust or the Lexus IS350 with HKS Hi Power exhause (with and without HKS Silencer Inserts) & F-Sport intake.
I do have some other brands available across the interstate, but I don't often go that way, so I run what I run.
As well as I sometimes gas up over 40 miles away, and I can't vouch for their 93 at one of the stations, but the 91 at the more popular place runs great.

 

I don't think one is that much different than the other. I would however pick one or the other and primarily stick with it. Also, the one that's pumping the most fuel would be my choice as well as the fresher the better.