Gas Octane

93 before and after the supercharger install.
Usually Shell.

 

+1. I calculated it once, I think I was saving nearly $1 per fill up using 91.

 

Where is 85 octane on the poll for those of us at altitude in colorado??...It's equivalent to 87 at lower altitudes

 

If your truck has knock sensors as most modern ones do it retards the timing when it detects it to stop detonation or pinging. Higher octane will allow it to use more timing before the sensor says whoa there pardner.
So more timing will get you a bit more power.

We are stuck with only 91 here as many states.

 

I run 93.
Like other have said, the engine just feels happier with higher octane gas.
That, and when gas was 3-4 dollars a gallon I would actually save money over the long haul using 93 as opposed to 87.

 

Ah, so that's how it works: lower octane for higher altitude (believe me, I'm no engineer). I wondered about that.

 

That is correct, sir.

 

Where I live we either have 87 with no ethanol or 91 with it. I get better mileage (usually 3-4 mpg over a tank) using the 87. And like one here said "It seems happier" using the non-ethanol. Have found this with both my Tacoma and the wife's Honda Pilot.

 

I noticed the same milage between 89 and 91 personally. However, I do notice the engine is more responsive with the higher octane.

 

Detonation, not pre-ignition.

 

There is nothing to notice. It is a calculation. If you do the math you’ll find that you save money (or not). During the gas crunch last summer I saved about a buck per tank. Not much considering a fill up was about $80. However, why run 87 when you can run 91 for a buck less?

 

I tried running 93 octane for two tanks and didn't really see a difference, at least not for paying a $0.20 premium every time I fill up. So I run 87.

 

where do you buy 93 octane? Can we even buy this in CA at a pump station

 

93 is all we have in VA, 87, 89, and 93

 

In NH most stations sell 87, 89, and 93. Some sell 91 as well.

 

Same here. I don't even remember seeing 91.

HOWEVER, we only have 10% ethanol gas here. I've searched and searched, asked on multiple forums, but it seems that's all that we have in SC.

 

Same here, I was never able to find any stations that did not have 10% ethanol.

 

Well I will try a tank of 91 (we get that here in TX) especially if it does not have any ethanol in it. Just not having any ethanol is a huge plus. Ethanol does not have the same energy density as does gas. It is also corrosive. Ethanol also hurts fuel mileage. I can see the argument about timing retardation if knock is detected but neither of my V6 engines have ever knocked on acceleration or towing that I could detect. It won't cost a lot to try it anyway.