Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 4 of 4
  1. #1

    Default Best gas for outboard

    I have been thining of what is the best gas for my outboard. The tag says to use gas with 89 octane rating. Mixed at 50/1 Locally I can get 3 grades of fuel. Reg. 87 mid grade 89 premium 92 to 93. My question comes up from checking out the way fuels sell. The fast seller is 87. The next is the premium. The slowest seller at a station is the mid grade 89 octane. I have always heard that fuel will loose octane sitting. If the mid grade moves the slowest than how much loss has there been? My thoughts are would you be better off mixing the 87 & 92 octane so that you would have a fresher fuel? Cost would average out about the same. What are others oppions?

  2. #2
    Moderator JB's Avatar
    Join Date
    Mar 2001
    Location
    The Hideout, Whitt, TX, USA
    Posts
    45,903

    Default Re: Best gas for outboard

    What make, model and year is your outboard, GR?Many of those labels refer to the technology of the time they were built. Gas has changed a lot in recent years.Almost all modern 2 stroke outboards run best on 87 octane unleaded. Most modern EFI 4 strokes can benefit from higher octane. If you have concerns about the gas aging, add Stabil to each tank.(239)

  3. #3

    Default Re: Best gas for outboard

    I have a 1972 Mercury 140 Horse inline 6 cyl. I even wondered about running premium, but had thoughts of it carboning up.

  4. #4
    Fleet Admiral Texasmark's Avatar
    Join Date
    Dec 2005
    Location
    N. Texas, USA
    Posts
    9,408

    Default Re: Best gas for outboard

    My '02 owners manual says use a minimum of fresh 87 octane (R+M/2). I thought about running premium also, but I asked several filling station operators how much premium they sell and they said not much. Now you'd think there wouldn't be much evaporation of the more violatile particles that make up the higher octane fuel, in a quasi sealed tank buried in the ground at 55 degrees, but who knows. So I run the gas that moves the fastest....87.Mark
    If you are new to boating or have a new boat, a knowledgeable friend could show you how to operate your boat and save you a lot of grief, maybe some money, and maybe your life.

Similar Threads

  1. How to convert I/O To Outboard? IS this a good deal for Outboard
    By sebas54 in forum Boat Restoration, Building, and Hull Repair
    Replies: 11
    Last Post: September 14th, 2009, 10:46 AM
  2. HELP need couple pages from outboard suzuki outboard repair
    By 04blacksrt4 in forum Yamaha & Suzuki Outboards
    Replies: 0
    Last Post: June 20th, 2009, 09:55 AM
  3. convert outboard to inboard/outboard
    By penguin in forum Boat Topics and Questions (not engine topics)
    Replies: 7
    Last Post: June 15th, 2004, 07:19 PM
  4. Outboard Down or Up when trailering? small boat & outboard
    By Mike M. in forum Boat Topics and Questions (not engine topics)
    Replies: 24
    Last Post: June 24th, 2002, 06:58 AM
  5. vintage Outboard Motors Corp. outboard
    By Merway in forum Other Outboard Brands
    Replies: 3
    Last Post: June 12th, 2002, 03:06 AM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic