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Kawasaki 2k5 GPX250 - OIL

Discussion in 'Technical and Troubleshooting Torque' started by pengo, Dec 23, 2010.

  1. No this is not a which oil is the best thread....

    I want to try a different type of oil for my bike to see how it goes, as currently its running off Motul 5100 10W50.

    Anyway after checking the owners manual it says it supports 10W-40/50 & 20W-40/50 which would be suitable for up here in QLD.

    So I went researching and others a bunch of oils and the only one I could source locally was Shell Advance SX2. After speaking to one place that stocks it they said they have 20W-50 of it in stock. To keep things short, I go to the shop and not until I have paid for it do I notice its 15W-20!

    Now my bikes manual doesn't mention 15W at all but the dude at the bike shop says they run it all bikes they work on in their workshop. Reading the back Shell says its for all 4 strokes. So how bad would it be to run this oil in my bike even tho Kawasaki doesn't specifically reference its (ie 15W-40/50)?

    I notice that 20W oil seems to be hard to source with 10W & 15W fairly common.

    Anyway thought I'd ask here to see what everyone rekons.

    Also my bike has over 40k on it and I am lead to believe running 20W oil is better for an old engine than 10W. Would 15W be a good middleground (as far as viscosity is concerned, not too thick not too thin)? Or doesn't wit work like that?


    Disclaimer: I don't know much about bikes so please be kind.
  2. Shell Advance SX2 is 2 stroke oil. You definitely don't want to be filling the sump of a GPX with that. :shock:

    As to the rest of your post, 15W-40/50 is basically just in between a 10w-40 and a 20w/50. The "w" number basically tells you how thick the oil is when cold, the other number it's thickness when hot. There are some oils with a very wide range of viscosity (ie very runny even at very cold temps. but still quite thick when hot), but generally the bigger the difference in the two numbers the more frequently the oil will need to be changed (due to having far more additives).

    Edit: Oh and FWIW I've found 20w-50 to be too thick for temps. below about 10 degrees with my GPX, but if the temps in your area aren't getting below 15 it should be fine.
  3. Why did I say sx2? I meant SX4! Its definately 4 stroke oil lol.

    This is it here: [​IMG]

    Thanks JD, very informative so 15W-50 should be fine then even tho the owners manual doesn't reference 15W only 10 & 20.

    I'll be changing the oil myself every 5,000k as its my primary form of transport and I regularly doing over 500k/week on it.
  4. Yeah 15w-50 should be fine, it'll just mean the engine's harder to start (and not well lubricated) at colder temperatures. But as long as you're not riding in temps. below 5 degrees or so it should be fine.

    If your owners manual has those little bar graphs for the different oils over temp then you can basically just draw in a new one with a start point in between the 10w and 20w oils, and the endpoint equal to the 20w-50. That'll be the 15w-50. :)
  5. Oh sweet, good to know :)

    As far as my question on an engine that has 40,000+km on it.. Thicker or thinner oil is best? Mineral, semi-synthetic or fully synthetic. Or should I just stfu now before I start a religious war? :p

    I'm lead to believe regardless of brand or type of oil (ie syntehtic, mineral) so long as its the right one for your climate and is changed regular it doesn't really matter - is no better/worse. Its the keeping the oil clean and fresh and engine adequately lubricated that is what matters?
  6. -Synthetic oils are more stable, and therefore don't degrade over time (ideal for engines which spend long times sitting).
    -Mineral oils however are cheaper, which means that you can change them more often for the same price and remove all the metallic particles they've accumulated along the way.
    -Semi-Synthetic oils are a bit of a wank given that they usually don't elaborate as to how much "synthetic" component they contain (and even standard mineral oils contain synthetic additives which technically make them "semi-synthetic" oils).

    The grade of oil (ie 10w-40, 20w-50 etc.) depends entirely on what temperatures you ride in. For some parts of the country this means changing oils between summer and winter (which is what I have to do). Edit: A thicker oil can reduce oil consumption on an old engine, but if this means less lubrication then you just get more wear, which leads to even more oil consumption, etc. (I figure oil is cheap and it's easier to just keep topping an old engine up when needed).

    If money's no object use a synthetic oil and change it often. For an old GPX though a good quality mineral or semi-synth oil is more than adequate, especially if you change it often. Just stay well away from cheap, no-name oils, they're usually nothing more than recycled oil that's been (poorly) filtered and made to look like fresh oil. I'd also suggest changing the filter everytime you do the oil since GPX filters are cheap.
  7. Thanks again JD. I was thinking of changing the oil filter every other (second) oil change.

    Well I was thinking of just using the Shell Advance SX4 15W-50 as its cheap enough and should be of good enough quality. I believe its a semi-synthetic (mineral oil + additives).

    So long as I do regular oil changes at the very least I should prolong the life of the GPXs engine. Its just to hold me over while I get comfortable with riding and get off my restrictions. I'll be getting a brand new bike once I feel confident and comfortable enough that I will be safe on a more powerful bike (nothing silly, just a 600-650cc sports tourer bike like a GSX600F).

  8. just an update, finaly did an oil change on the weekend and switched over from motul 5100 to shell advance sx4 15w-50.

    Ininitally there was a weird sensation that the bike was "vibrating" more than when on the motul, tho this has since gone. Can't really fault the oil as nothing bad has happened; no better or worse. I guess its better as it is alot cheaper than motul.

    For the cost of 2L of Motul 5100 I can get 5L of Shell Advance SX4.
  9. So you can change the oil twice as often for the same price :D. Doing so will benefit your engine far more than the fanciest lube.
  10. Maybe I should start an oil thread... here we go again!

    The first number in the oil name means what its relative viscosity (thickness) is at 20'C, or room temperature. This is important because the complex engine systems on modern high performance machinery usually require an oil with lower viscosity on startup.

    The 'W' after the first number means that the oil is suitable for winter use. This is aimed at countries where temperatures get very low, and 'winter use' means down to -18'C. Thats bloody cold by anyones standards.

    The last number means the operating viscosity of the oil at 100'C, or properly warmed-up engine temperature. The higher it is the more protection you get, and the thicker the oil when it is warm.

    So, a 10W-40 oil is an oil which provides good startup protection and only thins out as much as a 40-weight oil would when hot... and is still suitable for winter use! Its miracle stuff, modern oil.

    Cheers - boingk


    Anyway, mate, its good to hear your bike is running well and you're enjoying it. I never use any of the hot-shot high-cost 'perrformance' oils either... I just look for the API rating on the back. SG has high anti-wear additives, so do SH and SJ. This isn't so important if you're running a moder, watercooled bike, but is more for if you're running older air-cooled machinery, or putting your bike under highly stressed conditions (ie racing, trackdays, motorcycle courier).

    On filters, every second change is usually enough. If you look in your owners or service manual this is usually what it outlines. Another tip is to buy multiple filters at once - I buy them for my XR in packs of 3 for $21... they're $15 each otherwise!

    EDIT number two:

    Well, yes and no. Semi-synthetic oils are made by getting a base oil (10, 15 or 20 weight etc) and adding microscopic synthetic polymer strands to it. At room temperature these strands just float around in the oil and it stays at its regular base weight or 10 or 20 or whatever. At engine running temperatures, the polymers bind together and stabilise the oil - thickening it.

    General industry consensus is that around 3 times the satrting baseweight it all you want to stretch an oil with polymer viscosity additives. So while 10W-30 and 15W-40 are both fine, 20W-50 is as well - its larger viscosity gap doesn't matter because it had a higher baseweight oil to start with.

    When you start to see oils like 0W-30, 5W-40 and 10W-50, they're almost always fully synthetic. The reason for this is because a semi-synthetic oil breaks down in your engine due to the high heat and mechanical interaction. The first parts to break down are the long, stringy synethic polymers that are giving you your optimum running viscosity (the '50' in 20W-50). What you end up with is a compomised, mono-weight oil. A 20W-50 might end up as mono-weight 30, for example. Either way, it isn't good.

    All that can be avoided by replacing your oil at the specified change interval.

    Cheers - boingk
  11. You mean just like the viscosity modifiers and stabilisers they've been adding to oils for decades without labelling them as "semi synthetic".

    This is different to a synthetic oil which is produced to a specific hydrocarbon chain length, rather than being distilled out of crude oil. Mineral oils are a mix of hydrocarbon chain length which averages out to the desired value. Over time the lighter compounds will boil off and the oil thickens, which is bad for the engine. If an oil is produced synthetically this won't happen, which is what makes synthetics good for long times between changes (like with military vehicles), or extreme conditions which would cook a mineral oil very quickly (ie racing). For everyone else changing the oil before it goes bad is usually cheaper and easier.
  12. Hey guys, i changed the oil last week and using shell advance sx4 15w-50 (mineral but has some synthetic additives, so is a semi-synthetic but labeled as a mineral oil). So far nothing bad to report. Don't know if its any better than the motul 5100 but at least its cheaper and so far the engine hasn't blown up. With the compression seals stuffed on my bike and so the bike "leaking" oil thru the airbox, its what I'll use until I replace the bike in the near future. I can keep topping it up (will actually just do an oil change once the oil level gets low enough) as its about $30 for 5L, unlike $30 for 1L of Motul! So I can put up with the problem until the bike is replaced and it won't brake the bank.
  13. A slight over simplification. There are several web sites describing how they are formulated: couldn't quickly find the one quoted elsewhere on motor forums (quite detailed and written by oils chemist) so resorted to wikipedia which gives a condensed version.

    "Semi-synthetic oils (also called 'synthetic blends') are blends of mineral oil with no more than 30% synthetic oil", "Group II and Group III type base stocks help to formulate more economic type semi-synthetic lubricants. Group I, II, II+ and III type mineral base oil stocks are widely used in combination with additive packages, performance packages, ester and/or Group IV polyalphaolefins in order to formulate semi-synthetic based lubricants. Group III base oils are sometimes considered as synthetic but they are still classified as highest top level mineral base stocks. A Synthetic or Synthesized material is one that is produced by combining or building individual units into a unified entry."

    "Chevron, Shell, and other petrochemical companies developed processes involving catalytic conversion of feed stocks under pressure in the presence of hydrogen into high quality mineral lubricating oil. In 2005 production of GTL (Gas-to-liquid) Group III base stocks began. Even though they are considered a synthetic product they are still mineral base stocks and counted as the mineral part of all semi-synthetic lubricants. Group III base stocks [with certain amount of mixture of PAOs and esters and Group V] are considered synthetic motor oil ONLY in the United States.[citation needed] Group III based lubricants are not allowed to be marketed as "synthetic" in any market outside of the USA."
  14. Which means they're still susceptible to the same problem of lighter fractions "boiling off" as a mineral oil. My original point was that the term "semi synthetic" is a bit of a wank in the way that it is all too frequently used purely as a marketing term to make an oil seem somehow superior - even though the exact nature of it's "synthetic" content is usually not stipulated.

    Personally I'd trust a quality mineral oil over a cheapo "semi-synthetic" any day.