Out1aw

iTrader: (1)

I did the calculations today and found that every fill-up would only cost me $5 more if I ran 93 octane fuel as compared to 87 that I run now. I also know that LS1 f-bodys are supposed to only run 93 octane to run correctly. So my question is: Is it worth the switch (hp and mpg wise) to 93 octane?

Thanks

04Denali

When I first got my truck and Before I put my supercharger on I ran a couple of tanks of 87 octane than I tried 91 octane is was about 5.00 more to fill up and got better gas mileage. It worked out to be a savings of 2.00 dollars a tank full

TouchOfEvil04

iTrader: (13)

I run 93 but my truck is tuned for it...

Quik

iTrader: (7)

honestly just run 89 unless your tuned for 93 and have mods.

bluecajun5.3

iTrader: (31)

93oct 24/7 right here.

CHEVY6000VHO

iTrader: (2)

I tend to differ with you on that 100%. My LQ9 6.0L is supposed to run without problems on 87 oct fuel. Of course with stock PCM tune. I don't think so.
I ran 3 different types of brands. Shell, Chevron, and Exxon. All 87 and 89 oct fuels from them made my truck clatter under mid to upper rpm acceleration. I placed 93oct fuel from all of them and no more clatter. It did this from day one.
After I had Nelson's 93 oct tune I got use to putting 93 oct fuel in with no clatter either.
A few months ago I had Allen Nelson take my tune out and put the stock one back in. I had it removed for warranty issues with brakes and a GM rep taking a look at it.
Anyways, I went a head and tried placing 87 and 89 back in it. Clatter came back just like it did when I bought it. It now has 24,000k and I'm back to 93 oct fuel again with the stock tune.
Mine just may have a slight bit more advancement in the program. I'm not sure.
The 4.8 & 5.3L engines may take to 87 oct with no problems due to the lower compression. I just know mine does not like 87 or 89oct fuels. Even from the better brand gas stations. I only use chevron and Shell primarily. I've tried different station locations as well with the same results. I thought maybe a few of them had bad gas, but not all the different ones I tried I would hope.
I guess my engine is spoiled!

Jim

Quik

iTrader: (7)

doesnt your truck state preminum only but can be had to run on lower if necessary? i know cause i have the same motor well same as it was stock as yours at one time that came from a SSS. you run 10.1 they run 9.5 and its plenty for 89. you have higher CR which needs more octane

merk7408

Just as a reference lets say you average 15 mpg with 87 octane at $2.90 a gallon. If you had a 25 gallon tank you would spend $72.50 to fill it up and ideally you would get 375 miles from the tank. Now lets say you switch to 93 octane and pay $3.10 a gallon, then you'd spend $77.50, which as you said is a $5 difference. Now lets say you get 16mpg, then you would ideally get 400 miles from the tank, and 425 at 17mpg. Now for the fun math, lets say you drove 1,000 miles at 15 mpg, you would spend $193.33 in gas (87). At 16 mpg you would spend $193.75 for gas (93), and at 17 mpg you would spend $182.35 (93). So if you are running 93 octane and only see 1 mpg difference, every 1000 miles you would be spending .42 more, but at 2 mpg difference you would save $10.98. Hope this helps a little.

Colby 04

holy **** you have a lot of free time on your hands

CHEVY6000VHO

iTrader: (2)

Yeah your right. The service department lied to me. They told me it would run fine on 87oct fuel.
This tells me they were wrong:
http://www.powerblocktv.com/crate/crate.html#12

Jim