Larry - Remember that there are only a handful of cars on the road today that use the Atkinson Cycle technology.
The information you are reading is only applicable to a limited degree due to the differences between Atkinson / Otto Cycles..

As time goes on - There will be more information that is applicable to the technology we have in these cars.

I've found some fault with the information you quoted from the consumer guide but for the most part it is correct when applied to Otto-Cycle technology in standard street driven automobiles.

Thanks!

 

People who put anything but the recommended octane are only fooling themselves. I find it hilarious when people claim to get better milage on higher octane. Fools. If anything it will be worse.

 

So if I read this right you are saying;

Anyone who claims to get better fuel economy on higher Octane fuel is a LIAR.

and that these people are FOOLS..

and that by putting in a higher than specified octane the fuel economy will be WORSE..

So nice to know that you are so open minded to newly implemented technologies (Atkinson Cycle) and are so openly offering your opinions.

Certainly you must certainly have your own "Atikinson Cycle specific" emperical evidence collected to support your statements...

We look forward to reading and observing this evidence.

Thank you..

 

Randy & Brian,
Interesting info on the advantage/or not of using Premium gas in the TCH. But for me, it just comes down to simple math. Regular is running about $2/gal and Premium is about $2.30/gal in my area. That is a 15% difference. Will I get a 15% increase in MPG by using Premium gas ? I get about 36 MPG in the TCH now on Regular. Is it reasonable to expect to get 41.4 on Premium if I drive the same exact way. I doubt that very much. So sticking with regular is the choice for me.

 

TK - I certainly agree that the economics (financial) are not there to support the potential increase in fuel economy.

Thanks!!

 

So, what should you use if you live in CO and regular is 85 and mid-grade is 87?

I did a little Googling and found this article:

http://www.koaa.com/news/view.asp?ID=251

I suppose I should get 87 next time. I have a pretty short commute these days so I'm not driving a whole lot and wouldn't be affected by the price difference between 85 and 87.

 

TK: I think it can be easily agreed on that despite any change in engine performance derived from higher octane fuels, non will translate into a MPG increase commensurate with the cost increase.

Performance (power) increases in the engine do not guarantee better MPG in a regular car let alone a hybrid.

In short, even if your TCH did increase it's MPG with 91 octane, you would lower your MP$ (Miles per dollar), thus spending more money to drive the same distance.

We are all richer having benefited from a fabulous discussion thou!

--Brian

 

It is basically a good idea never to use an octane level rated below the manufactures specs. My TCH came with an 87 rating so i would never use anything lower. In fact, we can not buy anything lower than 87 where I live.

--Brian

 

Randy, I also believe that the use of higher octane fuel is a waste of money. And I just hate to spend the extra 20 cents per gallon....just rubs me the wrong way..I even didn't buy a car once, because it called for premium. In the case of the TCH, I don't believe that the extra 20 cents per gallon will translate to any actual money saved overall...I am quite happy with my mpg, current tank at 41+mpg..

With that said, I have a question for you regarding the higher compression of the Atkinson type engine in the TCH....Somewhere on the toyota website (can't find it right now) I read that the compresion ratio is in fact much higher than the standard 4 cyl Camry engine, but one of the valves in each cyl is held open longer during the compresion cylce...I assume this reduces the effective compression to a more normal number??? Thereby reducing the need for the higher octane?

 

ROTFFLMAO!!!!!