***Please Note*** you can not create threads directly in this section. This section is made up of threads that have been moved here from other areas of the site
Results 1 to 10 of 10

Thread: Another take on oil

  1. #1
    07875 304772
    Join Date
    Sep 2003
    Location
    South Leicestershire
    Posts
    12,649

    Another take on oil

    This is an interesting post from a guy over on the Super Tenere forum...

    An interesting read



    'Actually, for internal combustion engines with pressurized oil circulation and filters synthetic blend is superior to synthetic.

    I used to be a "full synthetic in everything" kind of guy. Way back in the day I even used and sold Amsoil. But about a decade ago I bought a piston airplane. Keeping the airplane engine running well is more important in that than my Ford F350 diesel, Lexus IS, Yamaha Super Tenere, John Deere and Kubota tractors, Kubota Zero Turn, generators, air compressors, etc. So when I went looking for a full synthetic piston airplane engine specific oil and could not find one I was curious as to why not?

    I found an excellent article written by an Exxon oil engineer that answered the question. While synthetics have superior anti-corrosion, shear strength, resistance to break-down at high temperatures etc. they do have three negatives.

    First, they are more expensive.

    Second, full synthetic oils do not have the natural solvency of mineral oil.

    Third, full synthetic oils do not suspend particles as well as mineral oil.

    So in an application where there is no pressurized circulation from a pump and a filter - say in a rear end / differential full synthetic is superior.

    But when there is a pump and the oil circulates and eventually passes through a filter a synthetic blend is superior because it can suspend particles (combustion by-products like carbon, wear items like small metal particles, even dirt, etc.) and carry them suspended in the oil until it passes through the filter medium and is caught.

    Full synthetic oils do not do as good a job suspending particles so the abrasive particles end up dropping out and gunking up the lower areas where oil is present rather than being filtered.

    Mineral oil (non-synthetic base stock) also is a more effective solvent than synthetic.

    So given the choice between non-synthetic, synthetic blend, and full synthetic the best choice for engines with a filter is synthetic blend as it combines the benefits from both types of oil.

    No manufacture makes a full synthetic piston airplane engine specific oil because the airplane engines are not water cooled so they have more combustion by-products than water-cooled / temperature regulated engines. They also burn fuel with lead so there is lead residue in the combustion blow-by that gets into the oil.

    One manufacture did make a full synthetic piston airplane engine oil for a time - Phillips - but they ended up buying some airplane engines after valves stuck because the lead particles were not broken down by the solvency of mineral oil or carried to the filter and filtered out by the particle suspension capability of mineral oil. So the lead particles stayed in the oil and built up on the valve stems and caused valves to stick. So they stopped making the oil.

    I use Exxon Elite which is a synthetic blend and I use Rotella Synthetic Blend in my diesel trucks and tractors and other synthetic blends in motorcycle, etc.

    Not many people know that when there is a filter present it is better to use synthetic blend so I thought that might be useful information to people here. It is a bit counter-intuitive because we tend to think more is better.

    Full synthetic is better than straight mineral oil in any engine that sits because they tend to have more issues with rust on metal surfaces and full synthetic is far superior in corrosion protection than non-synthetic. But synthetic blend is just as effective at protecting against rust as full synthetic.

    Synthetic blend is a bit less expensive than full synthetic but you can't use the extended drain intervals to extremes that some people use with full synthetic because the base stock mineral oil has additive packages that wear out with heat and pressure faster than full synthetic oil loses it's lubrication properties.

    At any rate, just passing on what I have learned from the airplane experience. If you want a clean engine with minimal wear and no corrosion then synthetic blend is the superior choice over non-synthetic or full synthetic.

    In the rear end / differential / transfer case / gearboxes etc. still go full synthetic for the best protection when there is no filter. '


  2. #2
    Subscriber Click here to find out how to Subscribe
    Join Date
    May 2010
    Location
    Falkirk, Scotland
    Posts
    1,839
    Interesting read, but why do the manufacturers spec full synthetics for their motorcycles ???

  3. #3
    Subscriber Click here to find out how to Subscribe
    Join Date
    Jul 2014
    Location
    Gloucestershire UK
    Posts
    1,664
    My KTM 390 Duke specifies semi-synthetic oil and this must be why

  4. #4
    07875 304772
    Join Date
    Sep 2003
    Location
    South Leicestershire
    Posts
    12,649
    Makes me content I'm using Hein Fericke 10/40 semi synthetic in the S10

  5. #5
    07875 304772
    Join Date
    Sep 2003
    Location
    South Leicestershire
    Posts
    12,649
    Makes me content I'm using Hein Gericke 10/40 semi synthetic in the S10

  6. #6
    Subscriber Click here to find out how to Subscribe
    Join Date
    Jan 2013
    Location
    Gibraltar
    Posts
    2,382
    Very interesting read. Thanks for posting.

  7. #7
    Subscriber Click here to find out how to Subscribe
    Join Date
    Nov 2006
    Location
    Uttoxeter, England
    Posts
    1,784
    Aha - the cheapskates were right all along!

  8. #8
    Subscriber Click here to find out how to Subscribe
    Join Date
    Jul 2009
    Location
    not allways where i should be
    Posts
    339
    depends who`s paying the wages and giving freebies out.
    Quote Originally Posted by mcinlb View Post
    Interesting read, but why do the manufacturers spec full synthetics for their motorcycles ???

  9. #9
    It gets worse straight grade oils suspend particles better than multigrade
    KEA

  10. #10
    Subscriber Click here to find out how to Subscribe
    Join Date
    Jul 2009
    Location
    Aberdeen
    Posts
    9,979

    Click here to find out how to remove these ads

    Next week.......Nitrogen in tyres.....is it all hot air ?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Anyone attending a Ride Out or Event organised through the UKGSer Forums does so at their own risk.
UKGSer.com or anyone organising an event posted here will not be held responsible in any way for damage or personal injury sustained while attending any such events.

Members attending any such event do so at their own risk.

The text, images, graphics, sound files, animation files, video files, and their arrangement on this Website are all subject to copyright and other intellectual property protection. These objects may not be copied for commercial use or distribution, nor may these objects be modified or reposted to other sites without prior written permission.

Disclaimer: Use or depiction of the BMW logo or trademark throughout this web site is for illustrative and editorial purposes only, and to the benefit of the trademark owner, with no intention of infringement of the trademark.

The UKGSer Forums may include adult content for which it cannot be held responsible. Your use of this website constitutes acceptance of the UKGSER network privacy policy

"Its about being a grown up hooligan - and if that means a dark visor, remus open pipe and a bit of speeding out of town then all well and good"