I figured since there was such a huge cost difference (I needed 8 gallons, and it was $0.20 per gal more), I would ask if my massive investment of $1.60 would do me any good. Anyone see any difference in mpg running 93 octane super?
Tests have been done and there was no benefit unless climbing steep hills at speed. Super Unleaded resists ignition more than Regular Unleaded so it is used in high performance applications. It's not a "more powerful fuel" and it is not any better for your car. Stick with 87 octane. You will not benefit from Super.
I wasn't thinking of going all the way up to 91 or 93, but I was wondering if the 89 might be better than the 87 during these colder months.
It will make your car lighter by $1.20, so there will be a very minor MPG improvement if you pay cash. Other than that, the car is designed for 87 Octane gas in the US. (85 if above 4500 feet) Other countries calculate Octane ratings differently. Octane rating - Wikipedia, the free encyclopedia
There's a station in town that sells non ethanol premium, which might make more of a MPG difference, since the other petrol grades are blended with 5 or 10 percent ethanol. (I think anyway) I haven't tried it. but I wish I could get non-ethanol 87.
Some folks DO find a difference between E0 pure gas and E10 blended gas, but that has nothing to do with Octane Rating. It also usually comes out a wash financially to buy premium to get E0. (in theory, E10 has 3% less energy than E0)
I've looked and looked at the Shell pumps here in Vegas, and I can't find anything on them that seems to indicate an ethanol rating. Not sure what to conclude from that...
"Gas pump labeling when ethanol is added is NOT required in the following states: California, District of Columbia, Indiana, Kansas, Kentucky, Maryland, Michigan, Minnesota, Missouri, Nevada, New Hampshire, New Jersey, Ohio." Ethanol Labeling Laws - State by State Guide.
The problem with using non -ethanol 87 octane gasoline it usually is quite a bit more expensive than 10% Ethanol 87 Octane gas. I know in Longview Washington non ethanol 87 octane gasoline is $3.659 / gallon and regular gas with 10% Ethanol is about $3.209 per gallon. Even if you get 3-4 mpg it will cost you more per mile than the ethanol blended gas.
Well, shoot, Jimbo! How the heck am I supposed to know? Actually, since I pretty much only gas up at two different locations, and I know the staff very well at one of those, I suppose I could ask... not sure the clerks would know, but maybe if I could catch the manager when he's in.
Octane is a measure of resistance to detonation under load. Octane rating - Wikipedia, the free encyclopedia Sustained full load is where detonation is most likely to occur, so yes. Higher octane is better when going up a mountain with full throttle at a low elevation, you will accelerate slightly faster. You will not get better gas mileage according to the same tests of a Gen 1 Prius reported by Bob Wilson, as I recall.
If you accelerate faster in a shorter amount of time wouldn't that mean that you save on gas or get better mpg? I'm confused lol
Perhaps, but that does not mean he can measure it. Mr Wilson lives in Alabama, it not like he has long up hills available. By comparison, you can get valid acceleration numbers in a 1/4 mile.
There's a gulf between the proliferation of higher octane pumps and the cars actually needing the stuff. Pump Fiction - Marketplace
Our formulations are a little different down here (and for the record, I'd never in my life heard of "winter blend" before coming to PriusChat ) and our Ethanol situation is slightly messy. As per Fuel Type - Ethanol's effect on MPG | Page 2 | PriusChat our non-Ethanol standards are 91 RON / 81 MON (meaning 86 in US numbers) for "Regular Unleaded" and 95 RON / 85 MON (meaning 90) for "Premium Unleaded". There is also a higher grade Premium Unleaded at 98 RON. Regular Unleaded with no Ethanol is harder to find these days as there are limits on how much the industry can sell, but a couple of my local service stations have it. I used this exclusively for my first 3400 km (2100 miles). As it happens, I get fuel discount vouchers from my supermarket, but none of the service stations where I can use them have E0 any more. I noticed, however, that if I used them on Premium Unleaded, I would end up with a price similar to what I was paying for Regular Unleaded at my locals. So I decided to switch to Premium and see how it went. I've only driven another 850 miles since then so it is still early days, but my observation so far is that it hasn't made a discernable difference - it appears the various other factors have much greater impact on mileage, so I haven't detected any trend amongst the noise. Ultimately my challenge is my short commute - the ratio of those to other drives is what comes out in my Fuelly figures. I managed to set a new record of 4.4 l/100km (53.5 mpg) on the way in today... but then on the way home which is downhill I had a bad warm-up run and it killed my mileage. Always the way... I need my weekend drives! The regular/premium thing just seems to not enter into it.
Premium is useful in high compression engines because it resists the detonation a lower octane fuel might cause. The C does not have an engine in which it might be useful. It is a waste of money in our C's. For people so enthralled by the lure of saving fuel, thus fuel costs, this is not something to be of question. Embrace the 87 and eschew the 91 or 93. And stay away from ethanol it you have the chance.
This is a bit of a thing for us... as Regular Unleaded RON91 becomes hard to find without Ethanol, moving to Premium RON95 is a way of keeping away from it (which is one reason why I don't use my supermarket dockets to buy the E10 stuff).
