I've owned the car for a couple years my2002 ap1, but I've never considered using a higher octane up to now. I typically stick with shell vpower which is 91 max. I can get 94 for an added cost at a different station. Is there any benefit to 94 vs. 91 ?. Anyone feel a difference with higher octane fuels. I don't get any pinging with 91 under any conditions. Thanks for any replies.

 

With a retune you could see more power.
Unlikely to make any difference with out changes.

 

I used 91 when I first got the car, decided to give ultra 94 a try and didn't really notice a difference but when I went back to 91 I noticed the difference, I'm back to ultra 94.

 

Thanks for the replies.

They generally say you need to run 94 for a few tanks to notice the difference, any change on fuel economy with Ultra 94 as they use ethanol .

 

THe 94 is more knock resistant... so when it is hotter out (or anything else that increases knock likelihood) the 94 will maintain your stock power where the 91 might cause the car to pull some timing. but under normal/cool conditions there will not be a difference.

 

I've always used the higher grade... the price difference between 91 and 93/94 is usually less than $0.10, that's less than a $1 per tankful.

 

First - you need to make sure the "94" octane is AKI [shown as ((R+M)/2) on the pump], and not 94 Research Octane Number (RON). 94 RON is equivalent to around 89-90 AKI, and is not sufficient for the S2000. The S2000 requires a minimum of 97 RON (91 AKI).

Your profile shows you live in London Ontario - if that's correct...
I'm not sure if Canada uses the AKI or RON method for octane rating. If it's RON, you need to use 97 RON. If Canada uses AKI rating, 94 AKI won't hurt, and you will probably notice a slight improvement in certain circumstances. The S2000 can use up to around 97-98 AKI without any problems. Above that, an increase in octane will not be beneficial. Like with anything else, the law of diminishing returns applies. An AKI value above 91 provides a little insurance. Anything much over 93 AKI becomes a waste in $$$ - unless you're running FI, of course.

 

If 94 octane (or AKI as slipstream444 points out) is achieved by adding more ethanol than 91, then you'll almost undoubtedly get slightly lower gas mileage. While ethanol has a higher octane rating, it has lower power density than gasoline, resulting in worse mileage.

 

Yeah our 94 is ethanol enhanced , so fuel economy will be worse. I just put in my first tank today. See how it goes. Thanks for the replies.