Atkinson cycle and low octane fuels

I thigh this was interesting

"A by-product of this is that Atkinson cycle engines actually run best on lower-octane fuels. The slower flame propegation of high-octane fuel is detrimental to such an engine, and Prius owners who have made the mistake of running premium fuel in their cars have been rewarded with misfires, check engine and hybrid system warning indicators"

http://www.hybridcars.com/forums/showthread.php?98715-Hybrid-Gasoline-Engine-Atkinson-Cycle

 

Oh god, you just pissed a lot of people around here off.

 

thigh?
OP right now -->

 

haven't heard anyone talk of those issues and there are quite a few running it, myself included.

also, the many that are running the OV tune are running premium as well.

 

that was not my intention

 

does OVTune eliminate the Atkinson Cycle?

 

Its not a true Atkinson Cycle its "psuedo" and there is no "on / off" so no it isn't disabled in any way.

Edit: Quote on the same thread
"Although the engine cycle is called an Atkinson Cycle, it is not an Atkinson engine IMO. The Akinson engine per se is more defined by it's awkward linkage which proved to be impractical but did give actual variable suction and compression strokes. The Toyota engine arrives at the cycle through the back door so to speak by pushing some of the charge back into the inlet manifold as previously stated."

 

I know that. We call it the Atkinson Cycle. Why doens't OVTune turn it off? It's just valve timing adjustments.

 

OVTune:

"Atkinson mode is controlled by camshaft angle. The camshafts are controlled electronically and the angle changes relative to RPM and load. So there isn't a "atkinson on, atkinson off" type of setup it is continually changing depending upon what RPM you are at and what the calculated engine load is.
Atkinson mode is still fully functional on this tune (it's used in areas at low and mid load, mainly low RPM)"

 

So why can't they turn that off?

 

From what I understand, it's too integrated.
I might be oversimplifying it; you'd have to ask the man.

 

I can say with the tune you aren’t FEELing the underpowered elements the AC brings on stock. Power is there and linear FWIW

 

What

 

I understood what he said. AC is Atkinson Cycle.

 

People complain about the power in these Tacos and immediately assume it’s the Atkinson robbing the truck of its power. What is the bigger issue is how the truck delivers throttle / fuel and then it’s tendancy to smother the engine rich. I no longer feel Atkinson is solely to blame

 

I didn't catch that. I was thinking Air Conditioning or something else

Thanks

 

Torque management and the throttle sensitivity plays a huge role in how much power actually gets delivered. Most new vehicles in the past 5+ years have a ton of TM to save stress on the powertrain (and meet minimum fuel mileage requirements). Just turning down/disabling TM on most vehicles makes it feel so much more responsive.

 

Mine runs so much better on premium. Wont ever fill up without it again.

 

Mine runs much better with a shot of Nitrus, doesn't mean it's good for it.

 

If it runs smoother, has more power, and better mpg's. Id say its worth it