Here's a basic question for something I'm still trying to figure out.

What are the benefits of tuning for 93 octane? Is it worth it?

 

Basic answer, run slightly more timing on it.

More of a cushion when it comes down to pre detonation. kind of the reason when you don't want to get on it when you run 87 ,higher chance of knock. The higher the octane the higher compression you can run or less likely of the combustion going off at the wrong time.All depends on how much advanced timing or performance your looking for.

 

You can squeeze some extra performance out of 93. Chance you'll run into knock if stranded in a 91 state, but most states on the east half of the country have 93.

I think a tune is worth it to optimize bolt-ons. Also nice to dyno the car to see what you're putting down vs. stock. You can have different maps for performance or eco if that's a concern, but you'll never touch eco if you have it. I'm sure you could ask your tuner for a 91 map too.

Edit: At least for ECUtek, you get launch control as a feature.

 

93 tune for sure, I only run Shell 93. If it's readily available I'd go with that. 93 will produce better numbers than 91. Like others said, you can get a map for whatever you want. I have 5 maps: Stock, Tuned 93, Tuned 93 with flame/pops, valet, and security/anti-theft. You could easily have multiple maps for various fuel types.

 

Odds are high I'll never swap maps, just pick the best one and stick with it. No flame or burble map.

There's 91 octane at maybe half of the stations around here, but everyone sells 93. Access to 93 octane isn't an issue.

Planning on a tune this Spring 2021. Bought the EcuTek ProECU cable and key a few weeks ago.

 

Any reason you... shell out more for Shell gas?

@Rochester I was recently reading a post from over 3 years ago where you were debating on tuning. Glad you finally went in.

 

Yeah, I talk a lot. Takes me forever to make a move with any particular modification.

 

Octane itself isn't a power adder. Octane is knock prevention. In reality you want to run as low of octane as you can before knocking. If you don't knock on 91 then you won't gain more power on the same tune with 93. If you get a safe tune on 93 you won't see power increases with "race gas" on that same tune. Running more octane than needed actually hurts power.

 

Agreed. All valid comments, thanks. But it's not so much that I'm asking about the tech, I'm rolling over the cost-benefit on the likelihood of always pumping 93 octane after the tune. The basic "Is it worth it?" question. So far the answer seems yes.

Let me ask this another way. For anyone who switches their maps between 91 and 93, do you honestly notice the difference?

 

I know a guy that moved to TX from Cali and said he notices a difference, so take that for what it's worth. You can research the topic and see others will also say go with 93 if you can and have dyno numbers for both. Yes, octane doesn't directly add power but a tune will let you adjust timing to make more power. I would think your fill up cost difference would be less than $3. Go big or go home! Premium gas for a premium man, etc...

 

Quick question:
Are you going to get tuned on winter gas or wait until the switch over to summer gas?

From what I have read, winter gas has less energy density somewhere around 1.7%
https://www.caranddriver.com/news/a1...ine-explained/

 

Whatever gas that's available in May. If stations have switched over by then, well there it is.

And apparently that means 93 octane.

 

Do you ever use fuel additives? If you need a small boost in octane you could give this a try:
https://www.summitracing.com/parts/l...IaAqWuEALw_wcB
I really like using this stuff every once in a while to make sure the injectors stay clear and all that good stuff. Says right on the bottle that this is basically a small octane boost as well. I can tell as well because when I use it, the exhaust gets a little more rowdy and feels like it pulls just a little harder. Plus I know several people that also use it and like it too. It's meant to be good for your engine and just has that as a benefit.

 

I always add some Boostane when I fill up to make sure that my crappy Exxon 93 is good enough. I don't have access to any other 93 where I live.

 

I always fill up at Costco if I can. They normally just have 91, but are top tier, so I'll take what I can get.
I would like to fill up on 93 just once to see if I can tell a difference.