Let's talk fuels

Some of this has been chewed over in this thread:
Premium Gas and MPG | PriusChat

 

1) no

2) no idea

3) yes

4)

 

1. You should be using Reg 87 in almost all cases. The Premium octane does not help. Of course, E0 offers about 3% more energy/MPG in theory but high cost is usually not worth it.

As a very fine point, your area is not EPA reformulated RFG which means you might have more variations in energy content than some of us have in RFG areas. You might find with experimentation some brands or grades might have a little more MPG, but it's hard to predict, measure, and/or figure out. If cost was no object and you were trying set the Prius Chat per tank distance records, may want to try E0..maybe E0 Premium. Here in my area (RFG) we have no E0 at all, and no variations in grades except octane.

2. TopTierGas.com stations add more than enough detergent additives. If you are going to off brand smaller stations you might want to consider a periodic dose of Techron etc. Or go with a few tanks of Top Tier once in a while. Not sure since I just do Top Tier as we have them here.

3. Winter fuel is less energy maybe 2% less MPG (due to added butanes etc) but it's E10 so no change in oxygenated fuel level. That was the old days. Today it's E10 mandated summer/winter/USA-wide almost.

Of course winter MPG is stinky for many reasons in addition to the gaso.

NOTE: above comments for USA, and basically consistent with Toyota Op Guide which is the key referee - nothing here intended to over-ride the USA Op Manual.

 

John's Prius site has data, graphs, logs, etc.
For a Seasonal MPG graph see: John's Stuff - Toyota Prius and more . . . click on ===> Prius data ==> MPG graph (PDF)
.
imo, use E0 instead of E10 if you can. Ethanol is a political thingy.

Enjoy.

 

I see the list of TopTierGas.com brands is a really long list now.
Gotta be something for everyone?

TOP TIER Licensed Retail Brands
76
Aloha Petroleum
Amoco
ARCO
Beacon
BP
Break Time
Cenex
Chevron
CITGO
Conoco
Co-op
Costco
CountryMark
CountryMark Plus
Diamond Shamrock
Entec
Esso
Express
Exxon
Holiday
Kwik Star Stores
Kwik Trip
Mahalo
MFA
Mobil
Ohana Fuels
Petro-Canada
Phillips 66
PUMA
QT
Quik Trip
Road Ranger
Shamrock
Shell
Shell (Puerto Rico)
Shell V-Power
Shell V-Power NiTRO+
Sinclair
Standard
SuperAmerica
SuperFuels
Tempo
Texaco
Tri-Par
Valero

 

Based on my experience here in Germany, anything that is not E10 (10% ethanol) with higher octane, is a waste of money. The car works perfectly fine as it is and for what it is designed for and fuel consumption is in line with my driving style and what others report. And I bought fuel from all sorts of suppliers, known brands, regional, supermarkets and even single point of sale fuel (we have a couple here).

The car now has 60k miles, and I never used any mentioned in 2) and not once I had a repair of sorts.

I think for modern cars designed for E10 fuel, 1) and 2) are a waste of money.

As for 3) I don't know since here there is no way to know if they are selling in winter anything different from what you get in summer. I think it is the same fuel. (Only diesel, they change the formulation to avoiding it freezing in the tank...).

 

moon shine runs greatWhen I taght school, "just say no you can always say yes later"

 

1. Unless the valve timing can go full Otto cycle, I don't see how higher octane fuel can help in a Prius. The EPA test blend for emissions and fuel economy is ethanol free and premium, though.
2. If you are sticking to top tier gas brands, it isn't needed. If it's mostly independent stations, then it might help. I've found that 2 to 5 ounces of KleanStrip paint thinner works just as well as most of the fuel system cleaners.
3. You sometimes will see a drop or jump when the market switches blends, but spring and fall have plenty of other random variables going on. Winter blend may help with cold starts, back in the day, but now I think it is a way refineries can off load excess butane.

 

Yes true lots of butane is available, so if butane cannot be used in winter gasoline, then there is no home for butane at all. I mean how many Bic lighters can they make? As a consumer butane affords cheaper gaso and less waste of petroleum barrels, as long as it is acceptable for the environmental re: smog.

>>>Re: Prius fuels choice, we should be very clear that so far we are discussing USA Fuel recommendations for Prius, and nothing we said above (except some fine points) is any different than Toyota recommendations in the Owners Manual, also Toyota is also apparently a supporter of the Top Tier Gas rating concept. Foreign countries whole new ball game possibly, and we are not over-riding the Toyota Op manual.

 

There is a kind of job called engine calibration engineer, normally the car has been verified and re-calibrated with kinds of local fuels by them before selling in a specific marketing area. Do what the Owners Manual says is very safe.
Higher octane fuel will bring slightly better performance (power & mpg), but may not worth the money. It is safe to swich between 87/89/91 fuel. But it is not recommended to switch forward and backward too often. The ECU's auto-tuning through sensors with different fuels needs some time, you may encounter some bumpy during switching.
And unless you drive your Prius very agressively or in a less developed country with low-quality fuels, fuel system cleaners won't be necessarily needed.

 

1. I flip open the Owners Manual, it says to use regular, that's what I do. AFAIK, only a very few cars actually NEED higher octane, and even they could manage fine on regular; albeit with some downgrade in performance. Basically engines with higher compression, and it would be noted in Owner's Manual.



2. Haven't used any gas additives in about 30 years, suspect they're pointless snake oil.

3. Must be happening, but I don't really notice anything. Any change would be masked by colder weather and what it does.

 

Octane is designed to prevent knock. You gain nothing from using an octane higher than that recommended for your vehicle, despite what the gasoline companies would like you to believe!

 

I use plus fuel with higher octane just to be safe !

 

You should use what is mentioned in the user manual. Anything else is probably a waste of money. More expensive higher octane fuels do not bring anything to cars designed to use a lower octane, like the Prius is.

 

No need. Modern engine controls include knock sensors, which allow all high compression engines but the ones in real high power sports cars to be premium fuel recommended, not required these days.

So if the car doesn't get a fill up often, or got some old gas from an out of the way station, the ECU will dial back the ignition timing to compensate for octane a little below regular. The gas has to be really bad for the system not to be able to handle it.

 

In the USA, around 85% of our sales are Regular, and 95% is E10.
So it's a good thing Prius likes E10 Reg, cause that's mostly what we got here.

The Premium sales are ticking up due to more new cars (not Prius) require Premium for turbo +MPG for CAFE regulations, so that seems to be pushing Premium costs higher. So that extra cost makes it even less attractive.

E10 sales are ticking up due to EPA mandates for max ethanol, so E0 is probably also getting harder to find and more expensive as marketers need to meet their ethanol quotas or pay a fee.