Is 93 octane ok to run in my HPDI?

[HAWKHPDI]

Only ethanol free fuel I could find was 93 octane, I usually run 91 when I am at home. I put about 8 gallons of 93 in the tank to top it off before my tournament tomorrow. I hope it will be ok, the manual just says 87 as a minimum if I can remember correcctly.

[Grant2]

I don't see a problem with that should be fine.

[BassManGuy]

Think about what octane reading means, the higher the rating, the hotter it burns. If your heads are not setup for higher octane, it will not be able to tolerate the hotter temps the higher octane creates, and you know the end result. I would say stick with 87 and use an additive like Startron or Stabil and definitely Ring Free Plus for the ethanol.

93 octane though, I would definitely be careful. I would watch this topic and see what the pro's say, they would know best.

The manual says 87, I would stay with it.

[Rich Z]

No problem running 93 octane on occasion. I would not run it routinely in a stock motor as it will leave more carbon deposits. Higher octane does NOT burn hotter; it burns slower, more stable and cooler and its best suited for higher compression modified heads.

[BassManGuy]

I thought I read that higher octane burns hotter in another thread. Just read it again, and it said it burns slower not hotter. I'm sorry for giving the wrong info. Thanks Rich, for clarifying.

[HAWKHPDI]

Well I only ran a few gallons in it, but I do always run 91 octance do to it not having ethanol in it. I ran her hard today as I was in a tournament and she ran like a top.

[Gotfive]

I had the same question, so I called Yamaha. They said owners manual says use a minimum of 87 octane. Most of the pure gas in this area is 91.