Premium Gas

^ That may or may not be true in Austrailia, but in the U.S. "advanced engine cleaners" are well regulated. We have a voluntary compliance here to attain a "Top Tier" rating, and this is endorsed by some of our larger OEMs (GM, Honda, Volksvagen, BMW, and Toyota.)
What Is Premium Gas? - Business Insider
Something not explained by the article I've linked below, there's a difference between "Premium Fuel Recommended" and "Premium Fuel Required."
The Prius is neither.

Generally speaking, there is no more energy in "premium" gas than regular, although IIRC Bob Wilson has done testing that disputes this, but only by an economically insignificant margin.
My personal opinion is that they use a little more ethanol (an octane booster) in "premium" gas than they do in regular gas, which makes some sense except that ethanol is a less energy dense fuel, which should make "premium" fuel a little less energy dense than regular gas.

I'll just continue to change my filters and fluids regularly. IMHO this will contribute to a "cleaner engine" more effectively than a sticker on a petrol pump that "says" that it's "better" for my motor.

YMMV!

 

That may or may not be true in Austrailia, but in the U.S. "advanced engine cleaners" are well regulated. We have a voluntary compliance here to attain a "Top Tier" rating, and this is endorsed by some of our larger OEMs (GM, Honda, Volksvagen, BMW, and Toyota.)
What Is Premium Gas? - Business Insider
Something not explained by the article I've linked above, there's a difference between "Premium Fuel Recommended" and "Premium Fuel Required."
The Prius is neither.

Generally speaking, there is no more energy in "premium" gas than regular, although IIRC Bob Wilson (who weighed in while I was typing this) has done testing that disputes this, but only by an economically insignificant margin.
My personal opinion is that they use a little more ethanol (an octane booster) in "premium" gas than they do in regular gas, which makes some sense except that ethanol is a less energy dense fuel, which should make "premium" fuel a little less energy dense than regular gas.

I'll just continue to change my filters and fluids regularly. IMHO this will contribute to a "cleaner engine" more effectively than a sticker on a petrol pump that "says" that it's "better" for my motor.

YMMV!

 

Yes many have run E0...the main impact is thought to be that E0 is 3% more energy content so you might see 1-2 MPG better on E0. However, normally you pay a lot more for E0, so its not the economic optimum.

Some Prius owners report more than 1-2 MPG better on E0, and that could be either (1) measurement error, or (2) at some stations, maybe the E0 gasoline itself has a little more energy content, so they could be seeing a double benefit. As we like to say here on PriusChat: YMMV (your mileage may vary)

 

It's a shame the number of cars that require premium fuel. I made sure our last two use regular.

 

That may be true but it has NOTHING to do with the octane rating of the fuel. NOTHING.

The fuel you are using might have a different formulation than the "regular" grade of the same brand.......but it might not too.
Octane in and of itself does nothing; it doesn't clean; it doesn't burn better (quite the opposite in fact) and it doesn't do anything else either.......in an engine that doesnt' need it.

It is a marketing "technique" (read that lie) that ties a better formulation with the grade that costs more so you will feel better about paying more.

It is entirely possible that you could get the same effect by using the lower octane version of the same brand of fuel.........and maybe putting in can of Techron every 3K miles or so and still save money.

Delusions sometimes make us happier but they are delusions none the less.

 

1: Well I never claimed it has anything to do with the octane rating, though a previous poster has pointed out that the less you need to retard your ignition point the more energy is available to drive the wheels and it keeps the engine cleaner by improving combustion.

2: My delusions are built on tested experience with vehicles other than the Prius, and inspecting parts on the Prius such as the inlet manifold, and valves and the spark plugs at 100,000 kms and 200,000 kms. Though I never worked as a mechanic after I finished my apprenticeship, I have had 50 years of mechanical experience with cars and trucks. I know when an engine is cleaner with one fuel than another.

 

And there is the delusion.
It's an opinion, based on incomplete information.
What exactly are you comparing it AGAINST ??

In order to really KNOW that you would have to have two identical engines running in identical conditions with the only difference being the gas in use.

Like I said, you have no way of knowing if that "sparkling clean" engine wouldn't have looked exactly the same way if it had been burning a lower octane version of the same fuel.

 

Toyota does not recommend regular gas, they state use 87 octane or higher.
And depending on which country you live in some oil changes need to be done at 5,000 miles.

 

Yes they DO.
It is worded that way because a higher octane will not cause any trouble; LOWER octane can and will.

By your fractured logic, no car maker anywhere in the world "recommends" regular grade fuel because almost all of them are worded that way.

 

I though you have stated in the past that higher octane fuel can harm the ICE?

 

Your memory is failing you.
I never said nor implied any such thing.
It might not run as good with higher octane but no damage will result.

 

Memory failure is very possible

 

The most stubborn of all falsehoods are those that were once true.

50 years ago gasoline had no mandated engine cleaners and used Tetraethyllead (TEL) as an octane booster.

When present in fuel, TEL is also the main cause of spark plug fouling. - Tetraethyllead - Wikipedia, the free encyclopedia
On the US highways, TEL begun to be phased out in 1973 (40 years ago) but was not banned until 1996, (18 years ago) so a great deal about old folks like me (58 years) know about gasoline is wrong. (I am very used to this, I began programming computers in 1969, so everything I know professionally is wrong every few years) Worldwide, the ban was in 2011.

The U.S. Environmental Protection Agency introduced the minimum gasoline detergent standard in 1995. - Top Tier Detergent Gasoline - Wikipedia, the free encyclopedia
So until 19 years ago, your gas could contain no detergents, and it was frequent to have more detergents in premium than in regular. Top Tier Gasoline, which must apply to all grades, was unveiled in 2004 (10 years ago) and specifies a higher concentration of detergents.

So today, name brand gas has adequate detergents in all grades, and without TEL is cleaner to begin with than gas from 50 years ago.

 

Clean is good, octane is good for a failing octane sensor. Never know when it may be failing, so as a car gets older, it is safe insurance to use Premium fuel.

 

I have never heard of a car with an octane sensor, googling octane sensor only results in other people asking if octane sensors exist.

I is possible you mean Oxygen sensors, your Prius has two. but more likely that you mean Knock sensor. It is the same in 2004 to 2014 Prius.

 

Yes - knock sensor (octane sensor).

 

Should your knock sensor fail, it does not detect octane, you will be able to read a code on the OBDII bus. No need to waste money 'just in case'.

 

Nice try but there is no such thing as an "octane sensor".

It has been a LONG time since I've heard a new totally invalid reason for wasting your money on octane though.