Best 4 Cycle Motor Oil?

Discussion in 'General Questions' started by stringer, Jul 20, 2008.

  1. stringer

    stringer Banned

    I was just picking up some things from the dennis kirk website and looked at oil. My EHO35 sits unused, waiting for various MB parts so it is a still a virgin.

    Anyway they have some very interesting, and expensive oil that I have not seen locally. I want to get whats best for my new engine, and since it only uses 100ml of oil, cost is not an issue.

    I have tried search and could not find any info. I have the subaru EHO35 pdf manual up, and it only says "Use class SF (API classification) or
    higher grade oil" Looking at their temperature chart, I'll need a single grade #40, or a multigrade 10W-40.

    They have a TON of 4 cycle oil there. Any idea which is the best? I wasn't sure if I should be looking at a dino, blend, or full synthetic here as the manual makes no reference in this regard.

  2. darwin

    darwin Well-Known Member

    For your break in period use a conventional oil it has waxes in it to help seal up the motor. After that you can use any high grade syn oil that you choose. Oil opinions are like buttholes everyone has one. Personally I like hybrid oils because you get the best of both oils.
  3. stringer

    stringer Banned

    Thats very good info, thanx!

    I will use a conventional oil to start. They have some exotic looking conventional oil too. I might try a bottle of PJ1 or something.
  4. Skyliner70cc

    Skyliner70cc Active Member

    10w-40 isn't a very good oil. It requires a lot of viscosity index improvers which can cause ring deposits.

    I would personally use a HDEO oil. It has greater amount of antiwear additives than a non-HDEO oil and a greater capacity to suspend particles which is important in an engine that has no oil filter.

    I would use Mobil 1 Delvac 5w-40, Shell Rotella T 5w-40, or Amsoil European 5w-40. Rotella T is the cheaper and not a "true" synthetic like Mobil 1 or Amsoil.
  5. mark2yahu

    mark2yahu Member


    I picked up some Mobil synthetic 0w-30. Yes, zero weight :) It's doing a good job in my Subaru engine.
  6. Skyliner70cc

    Skyliner70cc Active Member

    That's a great oil and should serve you well in protecting your engine. Just keep an eye out on oil consumption. Mobil 1 oils tend to be on the lower end of the viscosity range that the oil grade allows. For example, their 0W-30 weight is barely a 0w-30 and some consider it a heavy 0w-20 but it is within the API spec range for a 0w-30 but not by much.

    Believe it or not, I use a special 0w30 in one of my diesel cars. It costs $13.00/quart but was designed for 10% better fuel economy without sacrificing engine protection. The extra 4mpg I got was worth the extra cost over the 10,000 mile oil change interval (oil is actually rated for 25,000 miles with oil analsyis).

    Good luck with your ride.
  7. StevePA

    StevePA New Member

    There are 2 main schools of thought on engine break in. Search the web for 'engine break in procedures' and you will find them (Take it easy vs. get some pressure in there). It seems that no matter which way you decide to go the #1 rule is no synthetics until you have it broken in.
  8. stringer

    stringer Banned

    thanks guys i decided to get some PJ1 Silverfire conventional 4-stroke 10W-40 for starters. its should be pretty good stuff (i hope)

    i really like the idea of getting 10 oil changes per quart of oil lol. i will be changing my oil after every single use.
  9. sparky

    sparky Active Member

    (1) Why use straight 30W over 10w-30??

    (2) The rule about always using dino during break-in to seal the rings, then switching to synthetic later is definitely true.

    (3) The "rule" about not being able to switch from synthetic back to conventional oil is actually a myth. You may switch freely between the two, but that's just silly 'cause it's a waste of money.

    (4) I've always heard that synthetic oil needs to be "broken-in" itself.... that you don't see the extra lubricant benefits of synthetics until after 3,000 to 4,000 miles of use in a vehicle. At that point, you'd change oil filters and top off the oil, as opposed to removing the synthetic oil which is perfectly fine. This is why you can go for 10k to 25k miles without changing oil, but you *best* be changing that oil filter and topping it off.

    The whole dilemma (as far as I can see) with synthetics in MBs, is that these 4-strokes don't have oil filters. So you're forced to remove the synthetic oil at a very short interval no matter what. If we can't see benefits from synthetic oil until after it has been heated up (where the chemicals "break down") in the engine after hours of use... why even bother using synthetics in MBs to begin with??

    EDIT: My point is that your choice of oil filter is far more important than your choice of oil. But we don't have oil filters, so you're best off using a high powered magnet at the drain plug, like fetor has done.
    Last edited: Jul 21, 2008
  10. Skyliner70cc

    Skyliner70cc Active Member

    The jury is split on whether conventional or synthetic is best for engine break in. Numerous vehicles come with synthetic oil out of the factory. My last two new cars were spec'd for a synthetic oil for factory fill.

    I guess it comes down to what kind of synthetic is used. Castrol Syntec is a Group III oil which is not a true synthetic such as a Group IV (PAO basestocks) or Group V (ester base) oil

    Group III base stocks are considered synthetic motor oil ONLY in the United States. Group III based lubricants are not allowed to be marketed as "synthetic" in any market outside of the USA. It was a judge who allowed Castrol to label its Group III oils as synthetic.

    So, if you use a Group III oil which says synthetic on the bottle, its perfectly ok to use in an engine break in. Group IV or V...that's where the true debate is.
    Last edited: Jul 21, 2008
  11. mark2yahu

    mark2yahu Member

    I read somewhere that oil change intervals are longer than the well-known 3000 miles. 25,000 miles is news to me :)
  12. HoughMade

    HoughMade Guest

    Here's my someone said earlier- everyone's got one....

    I have been around and worked on small engines for 25 years. I have never seen an engine failure which I could ever say was, in any way, related to using the wrong oil- either weight, type or brand. I have seen plenty of engine failure from oil starvation, but that was because the oil was allowed to get low. Honestly, if you use a decent quality oil of the weight recommended, it seems you would be fine- change it when you are supposed to and check the level at every use and you will get long life.

    My one caviat is that most of the engines I have used over my life have operated at a maximum of 3600 rpm. My little Honda is supposed to rev to 7800, so that will make a difference. I would still doubt, however, if brand matters as long as the weight is right and it us kept clean and full.
  13. stringer

    stringer Banned

    Tons of great info here. I have learned alot.

    thanks to all!
  14. sparky

    sparky Active Member

  15. Skyliner70cc

    Skyliner70cc Active Member

    Oil change intervals on my VW are every 10,000 miles in the USA and with an onboard oil sensor only available in european models can be up to 25,000 miles with a specific type of VW approved oil. Many folks are doing 25k OCI (oil change intervals) with their vehicles if UOA (used oil analysis) supports it (oil analysis at a lab)

    Oil changes intervals on my wife's Jeep Liberty CRD are 12,500 miles for her driving style and 6500 miles for stop/go city driving predominant style. (BITOG for those in the know) is a great website to learn all about motoroils and ask questions about anything oil related in their forums. You may be lucky enough to chat online with a plastic surgeon who does his own oil changes on his million dollar Ferrari (and his other vehicles which are $$) to a lawnskeeper who wants to know what is the best oil for his lawnmower. I hang out there as much as I do here but I'm much less of a smart *** knowitall there as I am here.
  16. Nuttsy

    Nuttsy Member

    I don't hear the fat lady yet

    You ain't getting off that easy. I've seen oil questions go on for YEARS! Where someone will search the thread and chime in after the trail's gone cold.LOL
  17. mark2yahu

    mark2yahu Member

    So True

    That is the mechanical gospel truth!
    I've always gone by that...never let the oil get low, never over-rev the engine, change the oil on a regular basis. Personally, when I see that the oil's gotten really black and it's been 3000 miles, I change it. Who cares if it's designed to last 25,000 miles. There are particles in the oil, and soot. That's abrasive. I take good care of my vehicles, car or motorized bike.
  18. spad4me

    spad4me Member

    In my experience the best 4 cycle oil for autos motorcycles and any 4 cycle engine is royal purple of the proper viscosity, and changed frequently.
  19. mark2yahu

    mark2yahu Member

    Spad4me, you're third person to mention Royal Purple oil. Where do you get it from?
  20. sparky

    sparky Active Member

    What sense does it make to use SAE30 over 10w30?? ... particularly in a tropical climate like Florida?