Octane Boost: is it working?

He could. I'm sure a search function works too, since YOU are the one that isn't believing.

Here you go... took me less than a minute to find and I was incorrect, it was 15%, not 17%:
mpg with 91 vs 87, in your prius c | Page 3 | PriusChat

 

We need to realize that we are speculating because we do not have even simple basic analysis of the gasolines at XRAYDOUG's station. At least XRAYDOUG took the initiative to measure MPG performance. We would also need Octane, %ethanol, and density as a minimum.

The possibilities range from: for all we know, the dealer put Premium in the Regular tank and XRADOUG's meassurements are in error. Or, on the other hand, maybe the dealer did give XRAYDOUG some juicy 0% ethanol Premium and the refinery is formulating the Premium with more juicy energy content (which is one option). So maybe XRAYDOUG is actually seeing something as he is reporting.

I might expect up to 7% variation in Oregon. Maybe up to 10% variation if comparing E0 to E10.

In my area I am expecting 0% variation because I am in a reformulated gasoline region with mandated E10 (and also because I've been measuring denisty and %ethanol so I can clearly see I got no juicy Premium fun here).

 

Did you click the link? He has experienced this for more than one tank of gas. He has also included the Octane and %ethanol... two of the minimum requirements that you requested. If it were just one tank, I'd say whatever, but the fact that he's consistent at 87 and then consistently higher at 91 speaks for itself.

 

What is so "premium" about gas with a higher octane content?

Personally?
I think it's throwing money away, but usually burning premium gas only represents a 7-10 percent waste in money unless you're also in the "alky-haul is bad" movement, which means that you could be throwing away 10-15 percent of your money......but you're only throwing it away. It won't actually hurt the car in most cases.
I'm not so sure about the "Marvel Mystery Fuel additives" that they sell, but they probably won't hurt the car either.

OK.....
So if we presume that the trial-sized Priuses are knocking down 50-MPG tank-to-tank then we should see something like 53-55 MPG consistently for the same vehicles to justify the additional expense.
The adult-sized Priuses are usually pulling close enough to 50MPG to make the math work the same way, and there's one simple way to prove that there's no real-world MPG increase in using a higher octane fuel:
Look in the manual.

If Toyota could pull their CAFE ratings up by as much as 2-percent by just putting some info in the manual and a sticker that says "Premium Fuel Required" then they would have done it years ago.
Instead of just insulting people that drive trucks, the greens would be insulting drivers that put "low grade" fuel in their cars.


"There's a sucker born every minute..."
(Widely but erroneously attributed to P.T. Barnum.)

 

So you've done the experiment? As of right now, the only person I've seen that has done it and shown data is Xraydoug... I'd be interested in your data if you have it.

 

I actually tried a tank of "premium" back when I was in my hypermiler kick, and since the closest station to my office is a Mom and Pop place that claims that their gas is E0, I tried several tanks there as well.

No difference detected.

There is no 10 to 15 percent fuel efficiency difference with higher octane fuel in almost all cars.
Period.
Anybody that claims otherwise is either not very educated about automobiles, or is being influenced by faulty experimentation.

I can't prove that the Moon landings weren't staged either.

 

ETC this is the whole point, in general we could get better MPG.
Toyota cannot take credit for it, because EPA does the CAFE tests on Premium E0.
Then Congress says OK that's the base CAFE calc, but we want to add E10 as a mandate, and EPA says we want to mandate other parts of the gasoline recipes, so max MPG to some extent gets watered down by national policies. Of course the policies are for our for own good, we hope.

 

They were staged, at first... but that's a different argument.

I guess he doesn't know how to do simple math and his work, using multiple tanks of gas, means squat as evidence when there is nobody else doing the experiment.

I'm not saying he's right or wrong across the board, but in Oregon, in his car, it seems to be working. For him it is worth the added expense to get more MPGs. So far it seems that the only people negating his claims are the one's not doing the experiment (except you said you have tried it.)

For centuries the historians thought the world was flat and this was taken as fact, until it wasn't. But even when people came out with proof that the world wasn't flat, this data was false and he was lying and didn't know anything about the world.

 

Duplicate post deleted.

The key word is "seems".

For whatever reason, his results are a statistical "fluke".

My guess is a lot of users here have tried it and just don't feel that chiming in is worth their trouble.
I have tried a few tanks of premium in EVERY car I've ever owned and have noticed ZERO difference in any car that recommends regular.

The last one I did notice a difference with was a Nissan Maxima that showed a remarkable increase in power and fuel economy on higher octane fuel. Then I read the manual more closely and it said that while regular was OK, "premium" would be better. That was an early '80's model, I think.

And just to be very clear and specific: I have tried consecutive tanks of "premium" fuel in both my C and my Fusion and noticed NO difference.

 

I haven't tried Premium in our Prius, but have a strong hunch that there'd be little if any difference. The only exception would be Chevron's highest octane, which (up here at least) is spec'd to have no ethanol. But apples/apples, nuhu.

 

Well, he has mentioned he will continue his experiment, so we will see what comes of it.

 

I have no doubt that the results won't change much.
Whatever is different about his "situation" likely will continue to be different.

 

I just wish I had his difference.

 

I HAVE done Regular versus Premium in both a Gen 2 and a v, and I can say there is no difference. The person claiming he got a difference has a c, which I have never tested. But rest assured, if you give me a c, I stand ready to test it as well.

The c engine has no parts in common with the Liftback, v or PHV. 70% of the parts are different between the c and Gen 2. Without testing, it could be true. (I personally doubt it, but it could be true)

 

I can dig the flat-Earth argument, but people in every automotive and motorcycle based forum that I have ever been associated with have been grinding away on this topic for years.
I still maintain that there are enough goofy people in the government to mandate higher octane levels for "regular" gas for no other reason than saving the planet...IF there were a statistically relevant difference in fuel efficiency.

I had a 95 Protege (DX 5-speed) a while back, which is still the second-best car that I've ever owned out of dozens.
I got 40-ish MPG on the highway consistently over 255,000 miles, and I had exactly 1 visit to the garage with this car over that period (cracked exhaust manifold.)
The thing is?
If I put "regular" gas in the car, it would knock and ping.
I tried everything, but finally had to just suck it up and buy mid-grade to premium fuel for the car when I was below 5,000'.
The only reason I did this for the Protege, and still do it for the V-Rod is to prevent pre-detonation.

Maybe somebody from the API or with a M.S.Ch degree can explain to me why some people think that they're getting or they actually are getting more than 5-percent better fuel efficiency with "premium" gas.

Me?
I'm skeptical about that....just like some people are skeptical about the Moon landing...Elvis...President Kennedy...911.....

ah....."YMMV"

 

Oregon mandates e10 on both. If Costco is selling me something else I wouln't know.

I think that premium gives me about 15% more mpg. It cost about 4% more.

I have done my best to give an accurate account of my mpg using the two fuels. It can be tricky with a hybrid because I can hypermile it up over 80 mpg for tank average. I have tried to do similar driving for both fuels. Almost all my driving is in 25-35 speed zones.

Im not sure how to make a link. But the title Is 91 vs 87 octane in a prius c. It is listed under fuel economy section for prius c
mpg with 91 vs 87, in your prius c | PriusChat

 

^^^I wonder what Costco (or any station owner) is told about the gasoline batches they get?
In other words, do they just get the big tank filled up with zero documentation other than volume?
Or do they get volume and weight? Maybe ethanol % tried for? Maybe octane check?

 

Where I work, we get octane, gross volume, net volume (I believe that is actual vs. temperature corrected), ethanol content, and a few other things. If I remember, I'll write down the info.


Not a Dalek

 

Thank You Breadman!
So is the ethanol always 10%, or varies? I actually recently measured 7% on a Pennsylvania Premium, whereas I got 9% ethanol Premium in my RFG area. This was my first attempt at measuring ethanol so I could be low 1%....need to improve my ethanol technique.

I'd love to get weight and volume, that's what I really want. I do that myself too.

 

Octane boosters have no use in engines with 9:1 compression ratios. Neither generally does high test though some ingredients used to boost octane antiknock will increase BTu per pound combustion power but they are in greater quantity than a bottle of octane booster. High test aries a lot so don't count on better mpg or power. Refining is a result of inputs of many sourves of crude, some better than others.
One is toluene, which has higher heat of combustion; another is ethanol, which has lower heat of combustion that will lower mpg - ands power. There are specific compounds, like tetraethyl lead that increase octane ratings and used for decades but now outlawed so be sure to read the labels very carefully. Ones with tetraethyl lead (Pb) are found on the shelves but they carefully say acceptable only in old engines; even that is illegal.
For a Prius, any octane booster is a complete waste UNLESS you have added 85 octane or old gas. Then it might be useful but your power will suffer from old gas. Olsmean more than 3 months old.
BTW toluene requires special precautions in handling.