Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Oils aint oils

Discussion in 'Technical and Troubleshooting Torque' started by mrblack, Jan 23, 2005.

  1. Does anyone of a technical bent have the definitive answer on synthetic vs mineral oils?

    I have always used full synthetic oils in my bike and car and changed oil in both every 5k. Costs a lot more but whenever I am approaching redline it makes me feel better!

    A mechanic has suggested this is over the top and unneccesary and with oil changes of this frequency there is no benefit to be gained using full synth and I should spend the savings on wine women and song - any opinions - about the oils issue I mean.
  2. I'm undecided...

    but for example - how could a mineral oil of viscosity 30 be any thicker/thinner then a synthetic oil of viscosity 30? since that's what viscosity is right?

    most say that oils gets old/dirty because of the engine not the type of oil, so there's no reason why synthetic would last longer there

    on the other hand, my bike runs and shifts smoother with synthetic oil :)

    nice bike btw!
  3. I first started using synthetic in my original '86 K because it stopped a problem with the starter clutch which used to jam with gunk if oil dirty or getting a bit old.

    Nothing like sitting on a motorbike with the starter whirring like buggery but not engine action! You feel all those 230-odd kgs when you have to push start the damn thing!
  4. Synthetics are generally better at maintaining their viscosity and rating (SE, SF etc) under more duress (temp, and revs etc).

    If the oil manufacturer says their oil will last 10,000k, and the engine manufacturer say to use such and such a rating oil with X viscosity, then changing earlier is a waste of money, they both guarantee that schedule is good enough.

    But hey..if you feel safer... then thats your call, piece of mind means a lot.

    Changing too often is often a bad thing tho, the oil filter is rated in microns, ie the smallest particle it'll block, as it gets used, it will trap particles (duuuh!), which reduce the size of the holes in the filter, it will then block smaller particles, ie make the oil cleaner!
    Filters perform at their optimum when 1/2 way through their life (best balance between cleaning and restricting flow), so changing them early, or changing oil too soon means they never reach their optimum effect.

    If you trust the mechanic, take his advice, cos in fact over servicing does more damage than good!!

  5. In a bike id only ever run fully synthetic. For engines that are so finely tuned and highly strung the extra ability of synthetic oils to stand up to stress is worth it. Remeber the adds with Brocky crapping on about how mineral oil comes from the ground and no matter what will always contain a few impurities? Well he's right. In a car its not so important. They are much lazier motors than bikes.
  6. Go and kiss your mechanic. Sounds like someone with brains/ experience who's NOT onto this money-spinning bullshit that advertising wants to sell us.
    Apart from super hightech/ giga-rev engines (which are getting used that way, too), full-synth is a waste of income.
    Low-revving K100s/car engines are perfectly fine with modern semi-synth oils.
    Listen to your mech and bring him/ her a bottle of good plonk (NO synth here please :) .

    After 30 years of servicing dozens of bikes and cars of family/ friends etc.
    I never had a problem with semi-synth CAR-oils in ANY of them.
    Current SL-spec semi-synth is way beyond the specs specified in your manuals. Any non-relevant (anymore) comments in regards to friction modifiers etc. are just that, non-relevant anymore.
    Personal choice?
    Penrite HPR15 (15W60), perfectly fine in the big-single 650 Pegaso and the V-Strom 1000 (TL-motor). It's NOT a "bike" oil, btw.
    Same stuff goes into the family-people-mover.
    Bikes 5k intervals, cars 7.5k (due to its "scheduled" 15k intervals specified, which I think is too long)
  7. Heh. Do you know where synthetic oil comes from?
  8. autobarn???? :LOL:

    let me guess - something to do with mineral oil?

    Thanks for your advice Pete - do you have any comment on the "filter half life comment from JJ - that was new to me
  9. :D :D

    News here too...not really making sense either. Filters are made to xx-microns specs, designed to do the desired job fairly evenly for a specified period of time. There's not much to nil contamination of heavy particles during that cycle if the engine is healthy.
    5k filters on the bikes (yes, excessive perhaps...) 15k on the cars, 10k on older cars (mineral oils).
    Served me well for all those years, started that on a 50cc Honda Dax in the 70s and rode that little 4T for 62k (topspeed 70kmh with the wind pushing it downhill and a portion of homesickness) in under 2 years...20W50 Valvoline mineral at the time, car-oil), never used a drop of oil between changes, screaming it's heart out at 7000rpm ALL it's life :)
  10. Hey there Mr Black. How did you come by a 4 valve head on an '86 K bike? My '88 only has the 2 valve & I thought the 4 valve started in '89. Just curious thats all :D By the way I only use semi synthetic in mine -dry clutch so you can use whatever you please. I use shell Helix & it seems fine. Drips more out the oil/water pump than actually burning it -as lomg as you don't leave it on the side stand :LOL: :LOL:
  11. The filter comment comes from basic text book mechanics, the stuff I learnt in 1977, and taught in 1995, and used every day in the 19 years I worked as a mechanic, and sinse then occasionally as a "back yarder" (but still licensed tradesman).

    Just look in the manual (BMW Bike, car, lawnmower, wotever) see what oil it says to use, see how often they say to change it, and follow that.

    If you think its not enough, find a reputable mechanic that knows your machine, and get a second opinion.
    For your peace of mind, either reduce the change interval, or get a "better" oil, both is overkill

    If the book says 10k oil change with 10W-40 SF oil changed every 7,500, and your changing the "super whiz bang Celibrity advertised" SL rated oil every 5k, your probably wasting money, redline or not.

    Fast revving, hot running M-bikes (esp air cooled) will ask more of your oil than a (relatively) slow revving, stable temp car motor, bike manufacturers already have that covered by dropping the change interval to the usual 5k for bikes.

    My sooby has 12,500ks scheduled oil/filter changes, using "normal" oil and has never had an issue in the 127,000 ks its done in 5 years.

    Synthetic oil is generally better than standard oils, due to the better refining and processing, is it worth the cost? Your call.
    Interestingly Mazda do not recommend using any synthetic oils, and it will void your warranty if used in a Mazda rotary

    Your call, but don't trust Brocky, he's just telling what he's paid to say.

  12. my current wee beastie is a '90 4V which I have recently acquired - I used to own a 2V '86. i sold it after a few years in the early 90's to get a "faster bike" - ie a CBR100. Alas my one reget in life. Although the Hon was nice it was not my K - :(

    220km/h runs (downslope, tail wind) on dark, very early morning Perth freeways on the K should have been fast enough but I was young and foolish - as opposed to older and stupid now.

    long and short - got another K and fallen in love all over again

    I also use Helix (car and bike)

    Main difference I have notice between models? 90 has fatter tyres which good on road but I used to hammer my 2V on gravel in WA at 80-100 and it was steady as a rock where the 90 is a mite skittish - otherwise great
  13. If there was not much to nil contamination in a cycle (guess you mean service interval) then... why change the filter??? Why even fit them???
    Why does oil go black? wait.... could it be "contamination"

    "fairly evenly " over the life of a filter means it takes into account it's steady filtering and slow blockage, eventually the holes are too small, ie blocked, they started with an allowed oversize, (marginally) not filtering enough, they are optimum at the half used state. It's all compromise.

    It makes sense Pete, but I'm not here to argue, believe what you like, no problem at all :wink:


  14. Looking at the ever increasing service intervals of car-manuf (i.e. Renault/ Citroen-Europe 25k for small service/ oil...50k for big service/ oil+filter) it's a valid point. Bikes? Perhaps a bit different, but by how much? Built-tolerances are so tight nawadays that huge piles of shavings contaminating oil are just about non-exist. Looking at the sump-plug-magnet of my current ride, I haven't seen 10%shavings of what I had on the old SR500 :D

    It always seems to be. Hard to tell the real thing from hype/ advertising/ old-times-leftovers etc

    Yo... :)
  15. Thanks guys - that has been really helpful - however I have decided to trade the K in on an electric scooter so I don't have to deal with this
  16. Smiliar to helmets, oil filters have to pass SAE testing standards to ensure they meet engine manufacturers requirements. SAE J806 is a required test for oil filters, with a newer and optional SAE J1858 being available. These tests measure contaminant holding capacity, size of contaminant particles trapped, and ability to maintain clean oil. The test also ensures that oil passes straight through the filter when pressure is high (oil not yet thinned/warm or filter is blocked) and that a backflow valve is operational. (so that oil doesn't drain back into the engine without being filtered). Most decent/good filters will place their SAE testing capacity results proudly on their packaging.

    AN oil filter is either paper or some sort of synthetic material. Often the paper is also helped with something like cotton etc. Because of the design type, manufacturing, and filter material used, the level of performance between filters can differ. But in all instances, the filters have a scale of hole sizes that the oil passes through to capture different size contaminants. (Think of it as passing through multiple funnels, with the funnel hole getting smaller each time) Typical numbers for paper element filters are 40% at 10 microns, 60% at 20 microns, 93% at 30 microns, and 97% at 40 microns. (the percentage is amount of contaminant captured).
  17. "On the subject of whether or not to use a petroleum or synthetic motorcycle oil my recommendation is to use a premium quality synthetic. There is absolutely no comparison between the two. Synthetic oil has been proven to resist high temperature breakdown and shearing effects at higher engine operating temperatures for a much longer time period than petroleum oil and as a result allows the oil to stay in the specified viscosity grade much longer. Synthetic oil is more uniform in molecular structure and will reduce internal friction and thus provide for lower engine operating temperatures as well as provide for smoother shifting.

    We have measured the cylinder and cylinder head operating temperatures in two identical motorcycles; one running petroleum oil and the other a premium quality synthetic. We measured an average of 15-20 degree F. temperature difference after a very mild ride and short period of idling. At extreme engine operating temperatures and conditions this value can be up to 35-45 degrees F. lower with synthetic oil. We have received reports of this from motorcyclists that have oil temperature gages installed in their crankcase. We received another report of a customer that when he was using petroleum oil in hot summer heat and traffic jams he would have to shut off his air-cooled V-twin engine because it began overheating. After changing to a premium quality synthetic motorcycle oil his engine temperatures dropped significantly and he no longer had that problem on hot summer days in traffic. Again there is no comparison between the two and anybody that tells you otherwise has obviously not reviewed documented test data and facts clearly showing that synthetic oil outperforms petroleum oil in every category."

    Refer: http://www.smartsynthetics.com/articles/motorcycle_oil_technical_facts.htm

    The following is also an interesting read...
  18. Yup looks like another one of them giant screen bustin links....just when you thought your screen res was up the shit too :LOL: