Octane Useage History / (Just got) Unleashed 91Tune

[Wesmertz]

I bought my truck new 1 year ago. Used 87 octane for about the first 8 months thinking that was required. I averaged 20-21mpg. I though the power was amazing compared to the ‘99 Suburban 5.7 I drove prior. I found that the 2.3 would prefer higher octane so I began filling up with 91 octane. Didn’t immediately notice more power (likely due to the computer adjusting over the course of 2 tanks). I started getting closer to 22-23mpg on 91 octane after a couple tanks. Drove this way for a few more months until current time. Part way through that my wife lovingly filled my tank while I was inside grabbing snacks. Came out to find that she bough 85 octane. Decided to just burn through it. MPG dropped to 17-18 mpg. Got back to 91 and it returned to 22-23mpg. Definitely a noticeable power increase from 85-91. A couple weeks ago I got the Unleashed 91 Performance tune “power pack”. Holy shit. It’s crazy the difference in power. I waited about a week to install the better spark plugs it came with. When I pulled the factory plugs they were very much so blackened. I still haven’t installed the Rat Stat thermostat. MPG is bad because I am not over the excitement stage which causes me to play with the throttle too much. Though I am still getting 20-21 with my happy foot.

Questions:

- What caused my black factory plugs? Running 87 too long, Running 85 for a tank, or Running the tune with factory plugs?

- Should I be in a hurry to get the Rat Stat Thermastat installed?

-Expected MPG with Unleashed 91 Performance tune driving gently?

- How tough is the 2.3? With it tuned can it handle higher rpms without blowing/breaking?

- How much payload would prompt me to upload the towing tune?

- Anybody have a dyno graph with the Unleashed 91 Performance tune?

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[JasonTremor]

I bought my truck new 1 year ago. Used 87 octane for about the first 8 months thinking that was required. I averaged 20-21mpg. I though the power was amazing compared to the ‘99 Suburban 5.7 I drove prior. I found that the 2.3 would prefer higher octane so I began filling up with 91 octane. Didn’t immediately notice more power (likely due to the computer adjusting over the course of 2 tanks). I started getting closer to 22-23mpg on 91 octane after a couple tanks. Drove this way for a few more months until current time. Part way through that my wife lovingly filled my tank while I was inside grabbing snacks. Came out to find that she bough 85 octane. Decided to just burn through it. MPG dropped to 17-18 mpg. Got back to 91 and it returned to 22-23mpg. Definitely a noticeable power increase from 85-91. A couple weeks ago I got the Unleashed 91 Performance tune “power pack”. Holy shit. It’s crazy the difference in power. I waited about a week to install the better spark plugs it came with. When I pulled the factory plugs they were very much so blackened. I still haven’t installed the Rat Stat thermostat. MPG is bad because I am not over the excitement stage which causes me to play with the throttle too much. Though I am still getting 20-21 with my happy foot.

Questions:

- What caused my black factory plugs? Running 87 too long, Running 85 for a tank, or Running the tune with factory plugs?

- Should I be in a hurry to get the Rat Stat Thermastat installed?

-Expected MPG with Unleashed 91 Performance tune driving gently?

- How tough is the 2.3? With it tuned can it handle higher rpms without blowing/breaking?

- How much payload would prompt me to upload the towing tune?

- Anybody have a dyno graph with the Unleashed 91 Performance tune?

Pictures of old plugs?

 

[Wesmertz]

Pictures of old plugs?

Didn’t take pics. Old plugs are in my cans, but I’ve missed garbage day 2 weeks in a row not so I am not about to try digging. They looked like somewhere between these 2 pics.

 

[Blmpkn]

In 99.5% of situations the factory thermostat is the best thermostat to use.

Different temp thermostats are marketing snake oil at worst and a temporary band aid at best.

Sell the thing.

 

[JasonTremor]

Didn’t take pics. Old plugs are in my cans, but I’ve missed garbage day 2 weeks in a row not so I am not about to try digging. They looked like somewhere between these 2 pics.

Somewhere in between those two would tell me it is either running rich or you use the go pedal to its full advantage a lot or you drive a lot of shorter trips.

Not familiar with the thermostat, but all that matters is what temperature it opens up at and if Unleashed adjusted the tune for that thermostat.

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