Also, as an engineer with good knowledge of thermodynamics, I can tell you that, while a lower octane gasoline may have a detrimental effect on the engine and its performance, using a higher octane gasoline than recommended not only is uneconomical (i.e. waste of money), but could also lead to a slight increase in fuel consumption and even a slight reduction of performance. It's all about the heat of combustion parameter for different octane gasolines and other physics phenomena which are too technical to go into details here.

Sorry guys and gals for the disappointment but, in this case, bigger is not better.

 

Can you run e85 without a tune on our cars I have an 08 g37 sport coupe with 61k thank you for your time Lucas

 

I would very carefully verify whether Infiniti allows using E-85 in G-37.
Using E85 can impact seals on cars that were not designed for it.

 

always 93 either Shell Vpower, Mobil or BP

 

Whatever super-unleaded is near me when I run out of gas, all gas comes from the same refineries.

 

93 octane is normal Premium in my area. I always use 93 octane.

2-3 times per year, I fill up with 2-3 tanks back to back of Shell V-Power for the cleansing effect. Since Shell isn't convenient for me, I normally get Gate or Mobil gas.

 

I used to use 93 with all my cars that were tuned for it. Now every station has 91 and I have no idea why. We have always had 93 for as long as I can remember. Weird.

 

Second this. Loaners only get 87 from me, and I'll never buy a service loaner due to that reason. 93 from big box club stores, think Costco and Sam's. Might be a bit dirtier than say Shell, but I stay on my oil religiously as that's where the dirt in the gas ends up. FWIW i've been buying premium at Sam's for under $2 for a while now, been amazing AND I get 5% cash back on it all year long.

 

2012 G37, I use Shell VPower 99.9% of time. Every once in awhile I will fill with Exxon, both are Top Tier. I also use Techron Complete Fuel System Cleaner ever so often, just in case, which is on sale at O'Reilly's until 11/29/16. Paying around $250 more a year for the VPower vs Reg., about .68 a day. I keep my cars 10/15 years, no brainer for me.