Yamaha F250 premium fuel info

[96TL]

Me and Dale were talking about why the F250 requires premium fuel to run, and what would happen if you ran regular. I gave Yamaha a call to find out some more info. I'll post it here for those interested.

The rep I spoke with said it actually does not need premium fuel (93). It needs a minimum of 89, which is mid-grade, and usually the lowest grade found at marinas (which is true in my area). Its a high compression motor, tuned specifically to 89, and anything lower than 89 will retard the timing and MAY cause pinging or knocking and excessive carbon build-up. The F250 has a knock sensor, and will change the mapping to prevent engine damage, but you will lose some HP in the process. He didn’t know how much. Regardless, they still do not recommend running 87 at all. Just not worth the risk.

I dont think its really a big deal. Most high performance car engines today demand premium fuel as well (mine does). That’s what the motor was tuned for. The F250 is (was) Yamaha’s flagship motor. I’m sure they wanted to squeeze every drop of HP out of it as possible. I would probably save just $20.00 or so per tank if I went to 87 anyway. I only fill up 3 times per season. Not a big deal.

Also, if you're missing your owner's manual, you can view them online here.

http://www.yamaha-motor.com/outboard/se ... s=outboard

Dom

 

[grouperjim]

Thanks for the info. But my question from another post is still the same. If 87 equals less than 250hp, 89 equals 250hp, then what does 93 octane equal-----more HP or waste of $$?

jim

 

[Principal Reeler]

IMHP...whatever extra performance you sqeezed out of the 93 Octane wouldn't be worth the xtra monies it costs you over the 89.

Mac

 

[Megabyte]

Also, if you're missing your owner's manual, you can view them online here.

http://www.yamaha-motor.com/outboard/se ... s=outboard

Great link Dom. Thanks!

 

[PDP]

IMHP...whatever extra performance you sqeezed out of the 93 Octane wouldn't be worth the xtra monies it costs you over the 89.

Mac

93 should have zero additional performance gain. It would allow (93 octane gas) to be compressed more before pre-detonating or "pinging". Not necessary here because whatever the compression of the F250, it is appropriate for 89 (according to 96TL's conversation with Yami).

Like putting 93 into my wife's minivan. It just doesn't add performance because the engine does not need it to avoid pre-detonation.

Many "premium" high octane fuels have detergents or additives that can help your engine reduce carbon build up, but that is a separate issue (and also a reason Yami wants us to run Ring Free).

 

[grouperjim]

Thanks. I think I will add a little 93 now and then just to maintain the octane level of the existig fuel in the tank and to take advantage of any detergents/additives.

jim