I'm tuned for 91 but it runs way better on 87?

[Physh1]

Ok, I got a tune from you guys a few months back...03 Tahoe w 5.3

Optimized for 91, efan pin activated, cai, cat-back, reduced TM, etc...

I have been running 91 in it & things have been fine. My friend borrowed my truck & filled the truck up with 19 gallons of 87 (not knowing it needed 91). I get in the truck today & the thing hauls ass was more than I have ever felt.

So I have a tune for 91 but with a tank full of 87 it runs better & has more power. What's going on?

Cameron

 

[thehoe92]

just recently I noticed the same thing
I was VERY surprised when I put 87 in and one day started the hoe up and it was haulin ass

 

[Brandon X]

So if im tuned for 91 I can still put in 87 and won't get spark knock?

 

[blueflamed03]

you can put 87 in it, but the computer may pull timing to keep the knock sensors from going off....less timing/less power

 

[Colorado Hoe II]

Lower Octane fuel will burn with more power than a higher octane fuel. Higher Octane fuel will have less pre-ignition in a higher compression situation.

 

[JennaBear]

Ok, I got a tune from you guys a few months back...03 Tahoe w 5.3

Optimized for 91, efan pin activated, cai, cat-back, reduced TM, etc...

I have been running 91 in it & things have been fine. My friend borrowed my truck & filled the truck up with 19 gallons of 87 (not knowing it needed 91). I get in the truck today & the thing hauls ass was more than I have ever felt.

So I have a tune for 91 but with a tank full of 87 it runs better & has more power. What's going on?

Cameron

With a traditional tune we have to make assumptions based on modifications. Those assumptions are not always perfect, but apply to most. Colder weather may also be playing a factor.

 

[Physh1]

With a traditional tune we have to make assumptions based on modifications. Those assumptions are not always perfect, but apply to most. Colder weather may also be playing a factor.

So if I did the cable tune deal we could fine tune my setup? I've been eying the AutoCal...

Cameron

 

[JennaBear]

Yep, cable tunes allow us to fine tune to your specific vehicle.

 

[BOSS]

you can put 87 in it, but the computer may pull timing to keep the knock sensors from going off....less timing/less power

ya but they're saying more power Capt'n

 

[Physh1]

Sounds good...I'll keep running 87 since it runs better until I can pick up an AutoCal.

Thanks!