Super Unleaded

KARNUT · February 17, 2017

offensive!? I thought we were discussing. Go figure, after I paid you a compliment.

I said "rabbit trail" not rabbit hole. Rabbit trail is a debatesive term for following a discussion wherever it leads. I decided to follow the pro octane rabbit trail and offer an alternative proposition to spending more than folks need to to get the result they want. I wasn't aware that it was offensive to help others save money.

07Softail · February 17, 2017

Ok. Decided to go down this rabbit trail.

Premium is going to run 30-50 cents more tha regular in most areas. I can buy a case of 12 bottles of octane booster for $22.56, or roughly $1.90 a bottle that will treat 20 gallons of gas and raise it to 91 octane for about 9.5 cents per gallon.

9.5 cents vs 30-50 cents. And why would I want to buy premium? For those solidly in the "better to use high octane" camp, seems like a more cost effective approach. Kinda shocked no one else took the time to run the numbers.

Bullshit snake oil is all OB is! LOL

RT

Cowpie · February 17, 2017

Depends on brand and what it is. Some are indeed snake oil. There are reputable brands, primarily in the commercial market that actually do the job. One can actually make the stuff themselves if they have a mind to do so....

100 oz of Xylene / Xylol. 1 oz mineral spirits. 1 oz light lubricating oil like ATF. Mix it up and fill 8 - 16 oz bottles for use. 16 oz treats 20 gallons of fuel, making it 91 octane if starting with 87 octane gasoline. Mix it to 10 gallons and the octane rating of the fuel is 104. Lead was the old standby to raise octane, but Xylol is one of several primary components that are used commercially to bring octane up in Premium gasoline now, but it requires a small amount of lubricant to protect seals and such in the fuel system. Benzene is another that can be used for improving octane, but has had some minor environmental issues. Check the MSDS of the product and see what they are using for their primary component to improve octane.

Based on cost of that stuff, a home brew mix would run roughly $1.50+ for 16 0z. I can buy the same mix already done up and packaged for about $1.90 a bottle, so I have no desire to turn my garage into a chemical lab.

Dnt · February 18, 2017

I ran several tanks of regular 87 octane and had no pinging on the factory tune. Aftermarket tune on 91 octane produced a slight ping at light throttle in V4. Aftermarket tune updated and all is well now. I am not sure these guys concentrate a lot of their efforts on the V4 mode.

sdeeter19555 · February 18, 2017

I need to fill up and see what the mileage is, but as I figured; looks real close. I wasn't really doing it for mileage anyhow, but to minimize the surging I get at low engine speeds.

254.7÷17.143

=14.8573761885

That includes heavy DC and Baltimore rush hour (left Indian Head at 5pm), and probably 35 miles of hauling stuff around the back roads here at home. I also want to add that I had about 1000 pounds in the bed and other than fluids and a MF 12909 the truck is stock.

So on winter fuel, in rush hour traffic, loaded with 1000 pounds, and running 87, I was able to net nearly 15mpg...and that's a 2500hd.

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sdeeter19555 · March 29, 2017

Just as another update on 87, drove from Bloomington, IN to Reading, PA today...averaged 16mpg at 70mph on cruise. Driving back and forth to the job site (speed limit 50mph), averaged 17mpg. This is all hand calculated, multiple tanks. That was with about 1000 pounds in the bed...field gear and equipment.

As far as mileage, it makes no difference between the two. As far as running, truck definitely feels better on 91 or better.

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powerhaulic · March 29, 2017

neither comment relivent with your truck being a 2500 and a lower compression 6.0l

I need to fill up and see what the mileage is, but as I figured; looks real close. I wasn't really doing it for mileage anyhow, but to minimize the surging I get at low engine speeds.

254.7÷17.143
=14.8573761885

That includes heavy DC and Baltimore rush hour (left Indian Head at 5pm), and probably 35 miles of hauling stuff around the back roads here at home. I also want to add that I had about 1000 pounds in the bed and other than fluids and a MF 12909 the truck is stock.

So on winter fuel, in rush hour traffic, loaded with 1000 pounds, and running 87, I was able to net nearly 15mpg...and that's a 2500hd.

Sent from my SAMSUNG-SM-G900A using Tapatalk

Just as another update on 87, drove from Bloomington, IN to Reading, PA today...averaged 16mpg at 70mph on cruise. Driving back and forth to the job site (speed limit 50mph), averaged 17mpg. This is all hand calculated, multiple tanks. That was with about 1000 pounds in the bed...field gear and equipment.

As far as mileage, it makes no difference between the two. As far as running, truck definitely feels better on 91 or better.

Sent from my SAMSUNG-SM-G900A using Tapatalk

sdeeter19555 · March 29, 2017

neither comment relivent with your truck being a 2500 and a lower compression 6.0l

Sorry that I offered any tangible input to a conversation.

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Cowpie · March 29, 2017

I would say it is relevant. The 2500 is already almost 1000 lb heavier starting out. He had additional weight of approximately 1000 lb on board. Would be interesting to see comparison mpg from 5.3 with extra 2000 lb on board. Regular and premium results.

FreeAmerican · April 10, 2017

The Mrs and I took the camper out for the official start of our camping season. So I ran my truck down to right below and 1/8th of a tank and filled it up with 93 octane ethanol free gas. Normally I get around 10-11 mpg. towing around here. I got a solid 12.5 this trip. It also shifted to higher gears sooner and just felt more responsive.

Driving around after unhooking felt much more responsive. I normally run E10 93 day to day. The difference between the ethanol and non ethanol is enough to notice.

duquephart · April 10, 2017

Sounds like the sweet spot is 89 for a stock 5.3.

Donstar · April 10, 2017

Sounds like the sweet spot is 89 for a stock 5.3.

I agree! This topic has a history on this forum and I concluded long ago that I'll run 89 in my truck. I have the 4.3 V6 and have run 89 for the past year and a half.

Cowpie · April 10, 2017

89 in some places can be cost effective to use. A couple of points in octane can make a difference sometimes. Many places, 89 is only a dime a gallon more than regular. Premium, for me, is a hard sell. Just too much cost for what it delivers. Only if the vehicle required it would I use it. None of mine do.

GRN69CHV · April 11, 2017

Reference for mine is with a Hypertech Tune. Have tuned it for both the Premium Fuel Tune and the Regular Fuel Tune. First did the premium fuel (91 octane) tune, on 91 octane I could hear a slight bit of pinging at WOT in the upper rpms. Ran it like this taking it easy for few tanks of 91 fuel, last fill up was 93 octane, did not notice any pinging on the 93. Reprogrammed it to the regular fuel (87 octane) tune which is where it has been for about a year now. Have tried fuel from several different stations, bottom line, it doesn't like 87 octane, so I either run 89 octane if I can get it. Been buying most of my gas at the Costco near me (around here anymore you have few choices, there's a Sunoco few miles away that's in the other direction I travel, WAWA convenience stores or the Costco) they only have 87 or 93 octane. Motor will get by on 87 octane just fine for normal driving even with the tune installed as long as you drive with a light foot, but it does run better with premium fuel in the tank if you want to go WOT.

Posted the above back in February. As of last week I reset the ECM back to stock. Started noticing slight pinging on 87 octane, even under light throttle. My take on this is - a motor than will run with a factory tune on 87-89 octane is going to outperform a motor that is constantly into the knock sensor on 87-89 octane. Filled mine (had about 1/4 tank) with 87 end of last week. Now down to slightly less than 1/2 tank, will probably top it off with 93 tomorrow. Bottom line, yes motor will run on 87 octane, no it's not a good idea if the motor will see any load. FWIW, AFM has been deactivated, which IMO is the first thing an owner should do.

L86 All Terrain · April 14, 2017

The L83 like the L86 has a relitively high compression ratio too. 91+ is only going to make it's life easier. It's not needed, even my dealer told me not to waste money on premium for my 6.2L and to just run regular. They even filled the first tank with regular. I syphoned it out and run premium lol. 5$ a fill wont bankrupt me. 2 fills a month 24 fills X $5 = $120 - 150 more at the end of the year. Whoopidy doo. If you tow i would run at least mid grade at all times.