Gasoline Octane

Discussion in 'Starting a Lawn Care Business' started by soilman, Oct 24, 2005.

  1. soilman

    soilman LawnSite Member
    Posts: 106

    I just realized my Echo trimmer manual and blower manual say to use mid-grade gasoline, or higher, 89 Octane (R+M)/2. I have always been buying regular grade, 87 octane fuel, for all my small engines, and have been using this in my trimmer for a couple of years now, and have been using it for a few days now, in my new blower. I haven't heard any knocking or pinging. Not sure why I didn't read the gasoline requirement section of the owners manual before buying gasoline. I guess I just assumed all small engines are low-compression, and run fine on regular gasoline. My tecumseh engine -- the manual says NOT to use anything higher than regular grade, as it may damage the engine.

    Hmmm. I have 5 gallons of regular gasoline. I don't want to throw it out and buy mid-grade. That is nearly $15 worth of gas!

    Every other manual for every similar small engine, seems to say use regular grade. Why does Echo say use mid-grade?
     
  2. soilman

    soilman LawnSite Member
    Posts: 106

  3. soilman

    soilman LawnSite Member
    Posts: 106

    Sorry, I put this in the wrong forum. Should have put it in the mechanic and Repair Forum.

    Don't know what is wrong with me.
     
  4. Billz

    Billz LawnSite Member
    Posts: 181

    I've been running 87 in all my echos for years... never had a problem. I have a 6 year old trimmer, a 6 year old edger, and a 3 year old blower, and they are still working fine. They are only backups now, but start every time I need them.
     
  5. grass_cuttin_fool

    grass_cuttin_fool LawnSite Gold Member
    Posts: 3,504

    I have used the 87 octane for years but this year I went to the mid grade (89). I run mainly Stihl products and they recommend 89. With the price of gas its only 10 cents more for the mid grade per gallon. I figured if it saved me 1 break down or headache it was more than worth it
     
  6. soilman

    soilman LawnSite Member
    Posts: 106

    I know that Mobil gas advertisement say that they have a very good detergent additive package in all their grades. but there is no Mobil station near me. I am sure other brands have a good additive package in their regular. I wonder if there is some gas additive you can use. It seems crazy to buy 87 for my Tecumseh and Briggs engines, with them both recommending 87, and for the Poulan and the McCulloch, and 89 for just the Echos. I'd have to go to the gas station with 2 gas cans, and estimate how much each engine will use. It is complicated enough keeping a quart can filled with oil-gas mixture, ready for my two 1:40 2-stroke engines, and another can (a gallon can) for the 1:50 engines.
     
  7. Steppenwolf

    Steppenwolf LawnSite Senior Member
    Posts: 403

     
  8. TLS

    TLS LawnSite Fanatic
    Posts: 7,937

    I believe this still goes back to the amount of alcohol in gas. Premium fuels have less alcohol. Back in the day, regular unleaded could possibly have a high amount of alcohol in it.

    This has nothing to do with anit-knock in the two strokes.....simply not enough compression to be concerned with that.
     
  9. soilman

    soilman LawnSite Member
    Posts: 106

    No no. Follow the link i included in my second message.

    I think the key word there is "may." May cause heavy buildup of varinsh an dgum on piston surface and ring grooves; may shorten the life of the engine. If the regular grade gas truly has less detergents and anti-oxidants. But it may not. Esp if you get a gasoline with a known good additive package in all grades. I'm going to see if i can find info about this.
     
  10. mowtech

    mowtech LawnSite Senior Member
    Posts: 252

    I believe Echo is wrong. Higher Octane gasolines do not contain more detergents than regular gasoline. Go to any of the gasoline brand's web sites and you will see they make no such claim. See the following site of the Federal Trade Commision on octane:

    http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

    Look particularly at the answer to the question "Will higher octane gasoline clean your engine better?"
     

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