Why 85-Octane Gasoline Sucks And Why It’s Still Sold At All

[Bob Riebe]

https://www.enginelabs.com/news/why-85-octane-gasoline-sucks-and-why-its-still-sold-at-all/?utm_source=rss&utm_medium=rss&utm_campaign=why-85-octane-gasoline-sucks-and-why-its-still-sold-at-all

Worth a read.

[Lloyd Smale]

alcohol in fuel can in fact reduce detonation. The trick to is you have to get enough real fuel in the motor because compared to gas alcohol doesnt burn well. What alcohol does better then any octain booster is cool your pistons and that prevents hot spots that cause detonation.  For years we ran alcohol injection to be able to run more static compression (ie turbos superchargers) Flex fuel vehicle have big enough fuel pumps injectors and lines to support more fuel flow. Thats why your flex fuel car sucks for gas milage running 85. But a car tuned for it that has a fuel system to support it can actually make BIG power. Guys do it to modern factory supercharged and turbo cars all the time. Back in the day we had to find av gas or race gas. Todays guys run E85 but lots of it. Makes you wonder about emissions with it too. A gallon of E85 will produce less emissions then a gallon of 93 but is that true when you have to burn two gallons of e85 to go the same distance as one gallon of 93.

[RaySendero]

I use 89 octane ethanol free gas in my mower, chain saw and weed eater.
I use std 87 octane with ethanol in my vehicle.

If I fill up with the 89 it will get 4 mpg more.
Yes it is suppose to run on 87 Octane - It doesn't knock or pre ignite on 87.
I can't tell any difference other than the MPGs.

Some say there may be some carbon build-up attributing to this lower gas mileage???
Not sure its even there or how, if so, that would enable an effect octane vs MPG.
Only got 68,000 miles and it didn't slowly occur, I noticed MPG drop very first time I filled with 89 E-Free gas.
Do plan on using cleaners in oil and gas for a week before I do next oil change in case there is some internal carbon but not expecting that to help.

What do y'all think?

[Dee]

I like Seafoam. I occasionally put it in the gas tanks of my pickup, and SUV, mowers, weedeater, leafblower, and chainsaw.

[Drilling Man]

  I have a fuel injected motorcycle, I ran a mpg test to see the difference between no E vs. E fuel.

  I figured there would be a difference, but I wanted to see how much.  Well, the results showed no difference, none!  I don't know why, but that's how it came out and I was carful to make the runs as close as possible.

  DM

[Dee]

I ran regular gas with no alcohol until I moved to West Texas in January. My vehicles "seemed" to run a little better, and mileage was a little better. I also remember paying a little extra for it also.
Haven't found it here in this little town.

[mcbammer]

I ran regular gas with no alcohol until I moved to West Texas in January. My vehicles "seemed" to run a little better, and mileage was a little better. I also remember paying a little extra for it also.
Haven't found it here in this little town.

  A little ?   you' ll   pay a dollar more  a gal.  here  .  Lots of boaters use it so its  not hard to find .

[Dee]

I couldn't remember the price difference, but gas was considerably cheaper before The Hiden Biden Regime took over.

[oldandslow]

I ran regular gas with no alcohol until I moved to West Texas in January. My vehicles "seemed" to run a little better, and mileage was a little better. I also remember paying a little extra for it also.
Haven't found it here in this little town.

A gallon of gasoline contains 116,090 btu's, a gallon of ethanol contains 77,000. Of course  they ran a little better and got a little better mileage. Diesel contains 137,381 so that is why they are the mileage champs. I believe you are also at a higher elevation now and that is another factor in power as long as it is a naturally aspirated engine.

[Lloyd Smale]

when i put my car, snowblower mower outboards ect away for the season i put some seafoam and stabil in the gas and run then for a couple hours.

I like Seafoam. I occasionally put it in the gas tanks of my pickup, and SUV, mowers, weedeater, leafblower, and chainsaw.

[oldandslow]

My two mowers just get put up for the winter. It seems to work OK as I bought one of them in '07 and it has never had a problem. My other small stuff is battery powered now except for a small chainsaw and a leaf blower. Both are seldom used and I just run them dry after each use. My diesel tractor doesn't get anything either and I bought it in '10. All our gas is 87 octane, 10% ethanol around here and I can't ever remember seeing any 85 octane here.