I just purchased an Accord V6 and was told by the sales rep that I shouldn't use high octane fuel in my car. He said that the computers work extra hard when using anything above 89. Is this true or BS?

I don't know... I have heard that by using high octane you lower your horsepower in the new accords and I have also heard that you gain 10hp. If anyone has some reliable proof I would love to see it and read it.

you can use what ever octain gas you want, actually don't go lower then 86.

J30A4 has knock sensor which helps ECU to adjust timing to any octain gas.

....it belted out 217 hp and 195 lbs-ft of torque at the wheels. And this engine is only rated at 240 hp/212 lbs-ft at the flywheel! Of course, we did use premium gas to extract the most possible power and the J30A4 rewarded us with a surplus....

link to entire article-> http://www.vtec.net/articles/view-article?article_id=113992&page_number=4