Custom tune 89 vs 93

[jbr]

Since summer blend gas is finally back at the gas stations, I was thinking of bumping up my custom tune to 93 octane from 89 (all gas in my area has 10% ethanol).

I wanted to run a few tanks of gas through of 93 octane to get the 89 octane out of system. After a day of running the 93 octane on the 89 custom tune the truck was not responding well to the 93 octane. Gas is bought at Mobil. I only ran the 93 for one tank of gas and returned back to 89. Truck is back to normal.

A few questions.
1) Is it normal for the truck to respond abnormal when the custom tune is set lower than the octane gas? 89 custom tune and 93 gas. I know the other way around is not recommended.
2) Do most run the 93 custom tune? Why or why not.
3) Is there dramatic differences between the 89 vs 93 custom tunes with a stock truck?

Is their just a slight increase in Hp and torque using the 93 octane?

My truck is my daily driver. No towing, no racing

 

[HuskerRam]

I found the 93 custom tune didn't feel or respond as well as the canned tune; however, I thought the 87/89 custom tune was just as good. I didn't like the way the transmission felt/shifted with the higher tune. i've been running the lower tune for awhile now and am pretty happy. If you have 93 in now and are running the 89 tune, you shouldn't see a difference in performance since the PCM won't compensate for it.

I'm in the same boat (truck) you are...mostly stock with no towing. It's my DD, too.

 

[nightrunner066]

I found the 93 custom tune didn't feel or respond as well as the canned tune; however, I thought the 87/89 custom tune was just as good. I didn't like the way the transmission felt/shifted with the higher tune. i've been running the lower tune for awhile now and am pretty happy. If you have 93 in now and are running the 89 tune, you shouldn't see a difference in performance since the PCM won't compensate for it.

I'm in the same boat (truck) you are...mostly stock with no towing. It's my DD, too.

who's tune do you have?


I would ask the tuner to revise the 93 custom tune.

 

[HuskerRam]

I've got HF's tune. Admittedly, I still need to provide him some logs.

 

[jbr]

I am not displeased with my custom tune. I just curious if other people have compared the differences between their 89 vs 93 custom tunes. I know each truck responds differently based upon mods, environment, etc. I figured it would cost $6-10 each fill up running 93 vs. 89, not bad for more smiles with a more aggressive tune.

 

[jbr]

Bump

 

[DavidRam]

I feel a noticeable difference going from the 89 to just 91 HF tune. I would love to run a 93, but Cali doesn't offer that gas...

 

[jbr]

I feel a noticeable difference going from the 89 to just 91 HF tune. I would love to run a 93, but Cali doesn't offer that gas...

Performance, pick up, mpg? I put 93 gas in a few days ago to run the 89 out before I try the 93 tune.

 

[DavidRam]

Performance, pick up, mpg? I put 93 gas in a few days ago to run the 89 out before I try the 93 tune.

Performance, more responsive and pulls a little harder... I have never checked the mpg on my truck.

 

[jbr]

Performance, more responsive and pulls a little harder... I have never checked the mpg on my truck.

Thanks for the info.