Jonas

Im getting my 2011 GS A6 SC with the eforce later this week. The tuner told me to arrive with what ever type of fuel I want the car to be tuned for.

In Oklahoma I have access to 91 (100% gas) octane as well as 93 octane. He says you can get another 20-30 HP out of the 93. However I really enjoy road tripping my vette and wonder if it was tuned for the higher octane if I would run into problems as I travel. The tuner said I could tune it for 93 and be able to run it on lower octane but dont try to get into boosted situations when running the lower octane.

Also I have noticed when running the 93 I get about 5 mpg less than the 100% gas. As a lot of my miles are on the highway, this would equal a decent amount of lost fuel mileage.

My question is, is the extra bump in HP worth the downsides of running 93 octane. And if I did, is 93 readily available across the U.S.? Im under the impression comnifornia has very low octane levels and I was planning a trip up the coastal hwy this summer.

The_Raging_Bull

take your 91 and 93 octanes tunes with you, just run the gas all the way down, then switch tunes; and off you go at the new tune for whatever octane. My SCT tuner takes 5 to 10 minutes to switch via the OBD2 port.

Jonas

He is doing a dyno tune. Not using the Edelbrock tune. Forgot to mention that.

The_Raging_Bull

if his tune parameters will fit in the SCT tuner, its a 5 minute switch...

Motorhead-47

Tune it for 91. You really won't miss 20hp on a 500+rwhp car!

Thomasmoto

I'm having the same thing done on my 11GS A6 as well and I travel a lot as well. Get it tuned with the 93 you will be fine.

The_Raging_Bull

mine is tuned at 93, no issues. Plan your trip, download 93 octane station locations on your route.

Unreal

Can't always plan on 93 only though. Many states don't have any. As long as you avoid california and low elevation states that use 91 you should be ok. Higher elevation states like New Mexico, Colorado, Utah that use 91 are fine because they don't need the higher octane.

I would just error on safe and have them tune for 91.

TRINIC5

Your tuner is right, tune the car for the 93 octane and buy 93 when you can get it, even buy a octane booster and keep it in your car, while driving around, if 93 is not available you can buy the 91.
Now while running 91 don't get on the car hard with high boost but if you feel you will need to do so, just add the octane booster and replace it with another for safety sake at all times, but always remember a tune for 93 will be safe for 91 if you're not boosting the car hard or taking it to high rpm at standstill.

NICK YOSKIN

stock piston'd FI C6 should have 14* of timing. if modest boost levels are run 91 or 93 will work fine.

playtoy

I would just run the 91 if its 100% because you'll see better fuel economy with 100% gas over this ethonal blended crap.

Red Sleeper

Thank you!
You just reinforced what I think I have discovered by trial and error. As I experiment with my eforce it is looking like 15* is going to aggressive and 13.5* is very safe. I'm running 14.5* now but this summer I may have to back down a bit. Also, I have discovered that approximately 1* = ~9HP peak but don't hold me to it.

We have 93 octane with and without ethonol around here.

Jonas

Thanks for the input. I like the idea of getting a handheld tuner and loading multiple level tunes on it. It will be the more expensive route to go, but I can buy the handheld tuner, get the shop to load the 91 tune on it, then some time in the future go back with a tank full of 93 and get another tune for that. For now I think Im going to use the 91 tune as it seems to be the lesser of the two evils.

0Cunningham Motorsports

try like 11-12 degrees with about 8-9 lbs on 91