Prior to the current fuel price craziness, I was buying E-30 fuel for about $1.30 less than regular fuel. An octane booster adds about 20 cents per gallon to the cost of fuel. Is an octane booster a cheap way to counter the lesser MPG that you get with ethanol fuels? I don’t notice much difference in MPG between E-30 and regular fuel. I notice that the octane booster bottle doesn’t give much information about how much they are supposed to help boost octane.
Octane boosters?????
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I haven't spent money on octane booster in over 20 years, so things may have changed. But, I always read the back of the bottle and it would say something along the lines of "Raises octane by up to 3 points for up to 20 gallons of gasoline". I read this as saying it would raise a tank full of 92 octane to 95 octane, but apparently what they are calling a "point" is 1/10 of a point of octane, so that bottle was raising my octane from 92 points all the way up to 92.3 octane. I quickly realized that it was a gimmick and wasn't doing my tired 302 and 20R any good, so I haven't purchased it since. But as I said, this was years ago, perhaps things have changed as far as octane boosters go.
No.
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The fleet mechanic at my old job would give us 103+ octane booster to run in the ram vans that required better fuel than the 87 the district supplied. I didn't notice any improvement same sh!t poor fuel economy and the vans always ran lousy. Probably didn't help they were mostly city driven. I use in my personal vehicles Chevron with techron or the red bottle of stp twice a yr.
^This
I've not had anything that needed higher octane for nearly 20 years after I sold my SVT Contour that had a T28 bolted to it. It had two tunes, one for 91 and one for 93 AKI fuel.
What does octane rating have to do with MPG?
If you drive a mopar requires 89 or another car requiring premium both power and efficiency go down.
Very few cars are designed for it and the economy drop usually isn’t much.
I understand that.
This question is what I was commenting on.
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I’m no bean counter but yes one would think or to believe, if an engine was designed for higher octane and lower octane is being used the computer will make necessary adjustments in fuel trim along with other re-mapping to prevent knock and so on. End result would be an engine not running as efficiently as it could be and mileage being reduced.
Can I ask why so many post on here go combative?
Can I ask why so many post on here go combative?
Ethanol itself is an octane booster. And consider how much of it is needed to boost the octane from 85 to 87, about 10%.
So how much octane boost do you expect from a 16oz bottle of octane booster dumped into a 10-gallon tank? Shouldn't expect much.
So how much octane boost do you expect from a 16oz bottle of octane booster dumped into a 10-gallon tank? Shouldn't expect much.
The octane ratings we see on gas pumps (87, 89, 93, 94) result from mixing a station's base fuel with some of their top fuel, no?
Is the high octane level of top fuel created by a single ingredient?
If so, get some of that. Easy.
Is the high octane level of top fuel created by a single ingredient?
If so, get some of that. Easy.
Shel_B
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Not all cars have computers that adjust for knock, or octane level. You are, however, correct in your assessment about a computer-controlled system making adjustments and quite likely reducing power.
Octane boosters used by the petroleum industry have included tetraethyl lead, MTBE, and ethanol, in roughly that order. (As far as I can determine ethanol was used in corn-belt states instead of MTBE, before the phase-out of MTBE).
I remember seeing commercials that touted "gasohol" back in the 1970s. I think for ADM. And as a kid there were some of those educational short segments on Saturday morning, including one talking about how corn was turned into automotive fuel.
Ethanol as a fuel has been well known for years. The GM engineer who worked on the introduction of tetraethyl lead (and who was hospitalized as a result) actually believed that ethanol would be the better choice. The reason why lead was chosen was complicated, but had to do with it being a gasoline additive as well as the influence of oil companies that worked with GM.
The answer goes back to this day in 1921, when General Motors engineer named Thomas Midgley Jr. told his boss Charles Kettering that he’d discovered a new additive which worked to reduce the “knocking” in car engines. That additive: tetraethyl lead, also called TEL or lead tetraethyl, a highly toxic compound that was discovered in 1854. His discovery continues to have impact that reaches far beyond car owners.
Kettering himself had designed the self-starter a decade before, wrote James Lincoln Kitman for The Nation in 2000, and the knocking was a problem he couldn’t wait to solve. It made cars less efficient and more intimidating to consumers because of the loud noise. But there were other effective anti-knock agents. Kitman writes that Midgley himself said he tried any substance he could find in the search for an antiknock, “from melted butter and camphor to ethyl acetate and aluminum chloride.” The most compelling option was actually ethanol.
But from the perspective of GM, Kitman wrote, ethanol wasn’t an option. It couldn’t be patented and GM couldn’t control its production. And oil companies like Du Pont "hated it," he wrote, perceiving it to be a threat to their control of the internal combustion engine.
Nearly all modern fuel-injected engines have knock sensors and engine control units that can adjust the timing, even if they're tuned for maximum performance on regular. It's also a lot more advanced with distributorless ignitions. With a rotor, it would just adjust that mechanically. I remember the rotor on my 1995 Integra GS-R. The factory service manual said that the timing could be adjusted by turning the distributor. But mine also had a knock sensor where it could retard the timing if there was knock detected.
Something like this (I think from a Civic service manual):
The only real different might be the point where they'll set it for maximum performance. Most flex-fuel engines are tuned for maximum performance at about 100+ AKI.
Why are you buying an octane booster at all? What does your engine require? A higher octane in an 87 rated engine is a detriment, at least to your wallet. You may want to consider an additive if you keep that stuff in your tank more than 30 days. Alcohol separation is a real thing.
I found it interesting that the Ethyl Corporation (was the major producer of TEL) was/is HQ'd in Richmond, Virginia, along with some cigarette companies. I guess if one don't kill ya, the other will.
With a distributor ignition, what is adjusted mechanically is the base timing. That's done by a service technician when the distributor is first installed, or as part of a tuneup to make sure that the base timing is correct. (I don't know why base timing would ever change outside of a distributor replacement or someone tampering with it..).
Base timing is set with the ECU in a mode where it won't alter the timing. This is often done by disconnecting a jumper or, in the case of my 1998 Nissan Frontier, by disconnecting the throttle position sensor or by using a scantool that supports Nissan specific functions (like Nissan Consult). Then a timing light is used to set the timing by mechanically turning the distributor until the factory specified timing is set.
Once the base timing is set correctly, the ECU can alter the timing as needed for the engine operating conditions. This is done electronically, just as it is in a distributorless ignition.
One old performance trick on a distributor ignition is to advance the base timing beyond factory spec and then run premium fuel for a bit more horsepower.
E-30 is most likely around 91ish octane already. Every 5% ethanol content roughly adds a point of octane to a point. Over the counter octane boosters don't do much and are mostly a waste of money.
