For the guys who think they get more power with 91 octane fuel

[CheechDogg.0n37s]

Aside from the octane issue, there is potentially another reason to buy more octane than required. Last year when I was running Delta Sonic fuel (because it was the cheapest around) I noticed less than a smooth idle after a few months of use. About four tanks of Mobil 91 with the advertised 2X detergent package, the idle returned to glass-like smoothness.

I've since gone back to Sunoco 87 which, so far, seems to run well.

Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 80144 miles

That is one of the biggest reasons why I use 91 on my truck .... you can just tell when a vehicle is just not happy with the low grade fuel, my truck on 89 felt grump lol ... the idling , acceleration everything about it just didn't feel at 100% ... now with 91 it's just smooth as butter ...

 

[CheechDogg.0n37s]

Lol @HEMIMANN ... no lie homie ...

 

[HEMIMANN]

That is one of the biggest reasons why I use 91 on my truck .... you can just tell when a vehicle is just not happy with the low grade fuel, my truck on 89 felt grump lol ... the idling , acceleration everything about it just didn't feel at 100% ... now with 91 it's just smooth as butter ...

Did you have any different alcohol content between 89 & 91?
Have you ever tried 87?

Up here, state law required minimum 10% ethanol in all octane grades for automotive engines. Some people sneak over to the 91 octane no alcohol pump which is only allowed for small engines or collector vehicles, but I'm not gonna do that.

 

[CheechDogg.0n37s]

Did you have any different alcohol content between 89 & 91?
Have you ever tried 87?

Up here, state law required minimum 10% ethanol in all octane grades for automotive engines. Some people sneak over to the 91 octane no alcohol pump which is only allowed for small engines or collector vehicles, but I'm not gonna do that.

Chevron's 91 out here has no "booze" lol ..

89 and 87 have it, you can sometimes find a few Chevrons that carry 89 with no "booze" too, but 87 always has it ..

And I will never put 87 in my truck lol ... I tried the 89 for a whole year remember? Up until this past November 11th, I switched back to 91 and no way I will go back to 89 and no way I will even entertain the 87 lol ...

 

[White six four]

We still can't get Top Tier Fuel around here because of the claimed just-in-time pandemic chemical shortage. It's abusrd.

And now with winter blend gas back so is the check engine light in the wife's mitsubishi that they have a tsb out for the p0420 code to run top tier gas in it when it gets colder. It will come on and go out as it pleases til around May again. She buys the cheapest 87 she can find and it doesn't bother her it's on. Her car her move.

Now that camping season is done and I'm barely driving my truck it gets 91 since thats the only fuel around home that doesn't have ethanol in it. I've tried 87 89 and 91. I don't notice a difference maybe it runs a little better on 91 but could just be because of no ethanol in it. Now a head wind on the other hand I can definitely tell effects the get up and go and mpg.

 

[CheechDogg.0n37s]

And now with winter blend gas back so is the check engine light in the wife's mitsubishi that they have a tsb out for the p0420 code to run top tier gas in it when it gets colder. It will come on and go out as it pleases til around May again. She buys the cheapest 87 she can find and it doesn't bother her it's on. Her car her move.

Now that camping season is done and I'm barely driving my truck it gets 91 since thats the only fuel around home that doesn't have ethanol in it. I've tried 87 89 and 91. I don't notice a difference maybe it runs a little better on 91 but could just be because of no ethanol in it. Now a head wind on the other hand I can definitely tell effects the get up and go and mpg.

The average person which honestly it's more like 90% of all Ram owners or other makers for that matter, will never feel the difference between 87, 89 and 91 ... they just don't know what to look or hear for ...

But us that understand what too look for, what to hear for and how a truck actually responds with different octanes, we can tell right away ... I know I can ....

Like your wife, she doesn't care if the light is on with the 87 lol ....that's the mentality of those 90% out there ...it's only a few of us that honestly really do care what we feed our trucks ...

 

[HEMIMANN]

And now with winter blend gas back so is the check engine light in the wife's mitsubishi that they have a tsb out for the p0420 code to run top tier gas in it when it gets colder. It will come on and go out as it pleases til around May again. She buys the cheapest 87 she can find and it doesn't bother her it's on. Her car her move.

Now that camping season is done and I'm barely driving my truck it gets 91 since thats the only fuel around home that doesn't have ethanol in it. I've tried 87 89 and 91. I don't notice a difference maybe it runs a little better on 91 but could just be because of no ethanol in it. Now a head wind on the other hand I can definitely tell effects the get up and go and mpg.

Not sure why Mitsubishi thinks Top Tier Fuel will change engine combustion based on gasoline volatility? The Reid Vapor Pressure always changes every spring and fall when gasolines are refined with higher pressure (winter evaporation) for easier starting, and vice versa in summer for less VOC evaporation into the air from fuel pumps.

Top tier is ONLY the amount and type of detergent additives in the gas. Top Tier is more than API mandated minimum. Purpose is to keep injector nozzles and intake valves (on port injected engines) cleaner.

Anyway, does Wisconsin allow non-alcohol gas in vehicles? Minnesota legislature is bought-off by the agribusiness lobby. ALL gasoline MUST have 10% alcohol regardless of octane (exception for small engines). Same with diesel fuel and bio-additive.

I'd wager some Japanese engine makers aren't very fluent in U.S. gasolines.

 

[HEMIMANN]

btw, I can definitely tell the difference between 87 & 89 octane (both with 10% ethanol, of course). Little to no sputtering and roughness with 89 compared to 87. Knock would have to be loud for me to hear it - my hearing isn't great anymore.

Was just curious about 89 vs. 91. Without the OEM recommendation for 91, I'd assumed they don't advance spark timing advance any further to make use of 91's anti-knock capability.

 

[Wild one]

The average person which honestly it's more like 90% of all Ram owners or other makers for that matter, will never feel the difference between 87, 89 and 91 ... they just don't know what to look or hear for ...

But us that understand what too look for, what to hear for and how a truck actually responds with different octanes, we can tell right away ... I know I can ....

Like your wife, she doesn't care if the light is on with the 87 lol ....that's the mentality of those 90% out there ...it's only a few of us that honestly really do care what we feed our trucks ...

Correct me if i'm wrong but doesn't California require all their fuels to be oxygenated,that would explain a bit on why you notice a differance between 87/89 and 91

 

[CheechDogg.0n37s]

Correct me if i'm wrong but doesn't California require all their fuels to be oxygenated,that would explain a bit on why you notice a differance between 87/89 and 91

It's called alkylation and just about all fuel that is produced in the US is alkylate .... But yes, California is the only state that "requires" all gas grades "octanes" to have this in order to pass emissions ...

So this could very well be why I notice a huge difference betwee 87,89 and 91 ...But the times I have gone to Arizona, their Chevron 91 out there is also non-ethanol only the 87-89 has 10%

I have tried Shell and Mobil but only in my Corolla and you can also feel the difference with them ...

Other states can choose when to run alkylate fuel which is what the winter and summer blends are ... Not too many people know about alkylation, they just know about the different season blends ...

 

[HEMIMANN]

Thought alkylation was the chemical process to increase octane without alcohol?

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[CheechDogg.0n37s]

Thought alkylation was the chemical process to increase octane without alcohol?

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It is, makes the fuel cleaner, which in turn raises the octane level ...

 

[CheechDogg.0n37s]

Thought alkylation was the chemical process to increase octane without alcohol?

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You have to remember, Newsom want's all gas to have ethanol in California lol ... the CARB laws here are insanely stupid ... Alkylation allows low tier gas companies to compete here in California .... by using Alkylate fuel just about ever damn gas company here in California can be top tier ... they add their own additives, cleaners, detergents just like im sure other gas companies in other states and countries do , but here in California they will shut down a gas station without hesitation if they are found to be shady ..

Here in Riverside you constantly see them shutting down gas stations for being non-compliant ...

So Alkylation fuel is so much cleaner with octanes up in the 110s ... from what I understand, if you mix ethanol with that high octane gas, you end up with 87

Got this from an article a friend who owns some gas stations in Georgia sent me a while back :

Below is the actual article from a few years ago

Ethanol and Octane For Beginners

Ethanol is often talked about as a high-octane fuel. But not everyone has a clear understanding of octane and how it affects the performance of their cars. So let's start right at the beginning : what is octane? The official definition of octane is: the measure of a fuel's ability to resist...

mnbiofuels.org

In terms of its octane rating, ethanol has a rating of 113. As mentioned above, fuels with a higher octane rating reduce engine knocking and perform better. Also, almost all gasoline in the US contains 10 percent ethanol. When you mix 10 percent 113 octane ethanol with 85 octane gasoline it increases the octane two points to the normal 87 octane most consumers use. So the higher the ethanol content, the higher the octane. The octane rating for E15 (15% ethanol) is 88 octane and E85 (85% ethanol) is 108 octane.

 

[White six four]

Anyway, does Wisconsin allow non-alcohol gas in vehicles? Minnesota legislature is bought-off by the agribusiness lobby. ALL gasoline MUST have 10% alcohol regardless of octane (exception for small engines). Same with diesel fuel and bio-additive.

I'm pretty sure they do. Most gas stations by me, the Eau Claire area, have 87 and 89 with 10% and 91 with no ethanol. I've seen a few kwik trips that on the 91 it says something like for recreational vehicles, collector cars, etc but not all of the kwik trips say that for their 91. Today I put in 91 octane at a Cenex and all the 91 pump said was no ethanol.

 

[Wild one]

Alkylate is high in octane but has low volatility and can be added to motor gasoline and aviation gasoline to increase octane while meeting stringent volatility specifications.

 

[CheechDogg.0n37s]

So my theory on gas companies here in California is this ..

Joe down the street talked me into getting into the gas station business, he tells me he can get raw gas with 110 octane levels pretty cheap, but honestly it's still expensive as hell lol ...

He gets a connection with one of the local refineries to buy tankers of gas but only 110 or higher octane, he agrees to buy say 5 tankers per week, well those 5 tankers are going to allow him to mix his detergents, cleaners, ethanol %s and he now can sell 87, 89, 91 and even 92, 93 and 94 for much cheaper than than Chevron, Shell, Mobil and all the "top tier" gas stations around town ...

As long as the fuel he is selling is Alkylate, when the come and do the inspections, the tanks are clean, in compliance and he can mix any grade of gas he pleases as long as it is sold as advertised ...

This is why a lot of small gas stations around town make a killing selling gas

 

[CheechDogg.0n37s]

Alkylate is high in octane but has low volatility and can be added to motor gasoline and aviation gasoline to increase octane while meeting stringent volatility specifications.

Correct and California is the only State that requires all gasoline to be Alkylate , I posted the article a few days ago on another thread

 

[HEMIMANN]

Not sure why adding 113 octane ethanol to 110 octane non-ethanol alkylated gasoline yields an 87 octane blend. Pretty clear that ethanol was used as a cheap, taxpayer-subsidized octane booster that also reduces fuel economy due to less thermal energy per unit volume.

Higher octane fuel only performs better in engines that have high enough cylinder pressure to burn it. Whether be by compression ratio, turbocharger, supercharger, intercooler, or other means. Otherwise, a higher octane fuel without enough spark advance does not burn completely - producing more engine deposits.

Low octane pure gasoline is especially important for small gasoline engines with low compression ratios, such as Briggs & Stratton's (6:1 compression ratio, flathead, extremely sensitive to incomplete combustion buildup).

I worked for a major engine manufacturer, Onan. Also used Ford & GM Industrial engines. Then Cummins for diesels.

 

[CheechDogg.0n37s]

I sometimes sit and think about the strict fuel and CARB rules here in California and I say, even though the rules, laws, regulations and all that bs are so strict, it actually does benefit "Us" in the long run when it comes down to helping maintain our vehicles clean and running ...

We have the choice of running ethanol free gas in the form of 91-94 even though they should only sell 91 as the highest octane, but many Counties allow the sale of 92,93 and 94 for recreational purposes but I hardly see stations getting shutdown for selling 92 and higher for daily drivers lol ..

I love that the fact that I can buy 91 for my truck especially from Chevron, my truck is probably always going to be running clean as long as I maintain other areas of the engine and not neglect certain ones that the average truck/car owner seems to neglect ...

So that is why I run 91, it is clean fuel, high octane, no ethanol, top tier gas station and since 1990 when I first started driving I have always used 91 in every single one of my cars/trucks and never once have I had issues with the engines on any one of them ...

Only time I had issues with the engines in trucks that I drove where the company trucks/vans for dish network when we were strictly told to only use 87 in them lol ... and let me tell you, those vans/trucks were always in the shop with busted pistons, cam shafts, full blow engines catching fire at times lol ... no thank you .... 91 has worked for me for the last 25+ years that I have owned my own vehicles ... I have had small issues here and there like my corolla needing a new starter, alternator, clutch and the regular tune ups, but nothing engine wise ...

 

[Wild one]

Correct and California is the only State that requires all gasoline to be Alkylate , I posted the article a few days ago on another thread

Correct me again,but if they're adding alkylate to fuel,which has a lower voialatilily rate then gasoline ,that would mean there's less actual BTU's per pound of fuel then a pound of fuel with-out it.Which leads me to think there's more alkylate added to the lower octane fuels,consequently they would have a lower production of energy in comparision,to the higher octane fuels with a smaller percentage of it.Which would explain why you notice a differance in power,less BTU's means less power production. So if that's the case ethanol really has nothing to do with it,at least in California.