OTS v custom tune; your impressions

[apx632]

Excellent, this is the kind of info I was looking for.
Ive driven the car a lot over the last week, really the first serious miles since the weekend of the tune.
I paid attention to the timing for all for cylinders and the OAR on my AC3.
I saw major negative corrections on Stage 2 tune. Bad gas was indicated.
I downtuned to Stage 1 and it ran about the same but was much less negatively corrected.
Mileage is not what it should be though, I got only 26 on a 100 mile round trip.
Im thinking the gas is seriously bad and Ill try one tank at my preferred station and then if no better I will go with a custom right away.

I am very much a creature of habit. I generally only fill up at 1 of 3 stations in the entire city of Houston. Which I do mostly so that I know where to avoid if for any reason I get a bad tank of fuel, which has happened to me before. I never ran beyond stage 1 on the cobb because really for 175 bucks having a custom e-tune done by adam was so stupidly cheap you can't pass it up IMO. What is your OAR reading right now during this tank of fuel?

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[Brodirt]

I am very much a creature of habit. I generally only fill up at 1 of 3 stations in the entire city of Houston. Which I do mostly so that I know where to avoid if for any reason I get a bad tank of fuel, which has happened to me before. I never ran beyond stage 1 on the cobb because really for 175 bucks having a custom e-tune done by adam was so stupidly cheap you can't pass it up IMO. What is your OAR reading right now during this tank of fuel?

I didnt track the last tank since it was before I tuned and came from my reliable Sunoco station.
I filled up at a neighborhood Exxon the morning after I tuned, probably about 11 gal on top of the 4 from Sunoco (93 octane from both), and took a long 125+ mile round trip and wasnt running the AC3.
The mileage was not great so I was concerned.
I set the AC3 up and over the couple of days of driving on this tank it was 0 to .3, but I suspect the good gas is saving the day from being even worse.
Im getting big negative corrections too, that's why I went down to Stage 1 to see what the effect would be. Was -6 at a few moments in Stage 2, down to between -1 and -2 on S1.
When I get back in the car Thursday Ill go back to my reliable station and track with a fresh tank.

 

[apx632]

I didnt track the last tank since it was before I tuned and came from my reliable Sunoco station.
I filled up at a neighborhood Exxon the morning after I tuned, probably about 11 gal on top of the 4 from Sunoco (93 octane from both), and took a long 125+ mile round trip and wasnt running the AC3.
The mileage was not great so I was concerned.
I set the AC3 up and over the couple of days of driving on this tank it was 0 to .3, but I suspect the good gas is saving the day from being even worse.
Im getting big negative corrections too, that's why I went down to Stage 1 to see what the effect would be. Was -6 at a few moments in Stage 2, down to between -1 and -2 on S1.
When I get back in the car Thursday Ill go back to my reliable station and track with a fresh tank.

That is a very odd reading. -1.00 is 100% ideal of what you want your OAR to be. I've never actually heard of OAR going above that. Usually if it is below that is what usually is a bad tank. Sunoco for me is a no no when it comes to 93, as most local stations have the worst quality 93 fuel available. Which i always found odd because their e85 typically was always pretty darn good. Hopefully everything is good with your set up and the car was simply getting use to the new tune settings.

 

[Hellman109]

That's the big issue with OTS tunes, if your fuel(91/93) is't up to par you'll see lots of negative corrections and there's really not much you can do about it.(maybe trying another station, running 93 on a 91 tune, adding one gallon of e85, ext) Any good pro tuner will be able to work with your car/fuel/goals and provide a better tune for your car. I've had great experiences with both PD and Stratified, both were very professional and produced exceptional results...not so much with Adam. YMMV

Adam gets you to check your OAR before running any pull and to let it learn after any tune change. Bad fuel is bad fuel, if you have a protune then you probably dont have a device that tells you that your OAR is going bad.

Any pro tune can only tune to the fuel in your tank at the time, they should know if its bad, but unless you have them with you when you fill up each time, they cant adjust the tune. Adam gives you a "crap fuel tune" as well, so if you get crap fuel you can change to that map on the fly and be save... pro tune not so much, Lund don't do that either.

I live in a country with reliably good fuel though, so haven't had to deal with it, I can get 98 (US 93 oct) basically everywhere without issue, even on long interstate drives, so haven't had to deal with bad fuel ever luckily.

Also, for the negative corrections, is that at WOT or otherwise?

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