Full-synthetic best for summer?

Discussion in '4-Stroke Engines' started by iwasgandhi, Jun 15, 2014.

  1. iwasgandhi

    iwasgandhi New Member

    I recently purchased a new Honda GX35 4-stroke (35cc) to motorize my bicycle, but with very hot summer days ahead I'm wondering if it would be advisable to use full-synthetic SAE 5W-30. I want the best for my engine, and I'm concerned that a 4 hour ride, and sometimes an all-day ride, when it's over 90 degrees (F) out, may require some added protection -- something over and above non-synthetic oil. Honda seems to be quiet on the issue. What do serious gear heads think?:D

  2. bmg50cal

    bmg50cal New Member

    Better synthetics (don't go cheap) are superior to conventional oils in most regards.

    I would never run 5W-30 in the GX35 in the summer, fall, spring or even the winter where I live; the only time I would use it if I were running the motor in temps below 0 Degree F. 10W-30 is what it should use most of the time, but SAE 30 would be okay for summer use.

    I took this image from the GX35 manual, I suggest reading it. :whistling:

    GX35 Oil.jpg
  3. grinningremlin

    grinningremlin Active Member

    You want to break in on conventional and then move to synth.Takes forever to break in starting with synth.
  4. iwasgandhi

    iwasgandhi New Member

    Thanks for the above replies to my question. It makes sense to use either SAE 10W-40 or SAE 30 for a Honda GX35 in the hot summer. But why is it necessary to break in a mini 4-stroke by using conventional oil and then later switching to synthetic? For example, is there any danger to the engine by starting out with full synth? And, if it is, in fact, necessary to start out with conventional, then how many hours of use (or how many miles) should one use conventional before switching over to synth? And should one switch gradually, by using a manufactured blend of synth/conventional? Thanks. :D
  5. bmg50cal

    bmg50cal New Member

    The logic behind breaking in with a conventional oil is that the engine will break in faster. Conventional oil is not as slick and it will allow the engine to smooth out the rough spots faster i.e. removing material faster than a synthetic oil would. There is no problem with switching back and forth from a conventional oil to a synthetic; there is no need to gradually switch between them.

    I'm all for using the "best" synthetic oils after break-in; doing so should help an engine to last longer. The rest depends on the quality of the engine, how hard it gets used and maintenance schedules.

    I'm breaking in a Honda GX35 using a blend. I changed the oil after the first 1/2 gallon of fuel I ran through and the oil was already fairly well tainted. I'll change it again after I finish the next half gallon and switch over to the best synthetic I can find locally.
  6. darwin

    darwin Well-Known Member

    My opinion here. Dino oil has waxes in it and will help to seal the motor against leaks/wear. After that I'm a firm believer in syn oil, it does reduce wear according to most experts. A compromise is a syn/dino blend like Valvoline max blend which I use a lot in my cars, scoot and bike. Costs more but your change interval should increase, say 5k from 3k for dino oil.