Engine OIl Question
 

Hi folks,
With no bike specific oil readily available and my bike begging for a change I have put in some ordinary motor oil. (Castrol GTX3 Protection PLus 15w/40) Should I do another change soonish or will this oil be fine for the standard interval? The info on the back is all in foreign languages, which, being a Britisher, I have no understanding of. My manual says don't use motor oils with low friction additives but this Castrol stuff seems to make no mention of that. Any thoughts?
Matt

Oil, black gold, texas tea.
 

Honda and yamaha are big on no friction additives because they state that it will make your clutch slip. The main thing is to have oil in your motor. Oil is one of the cheapest things you can do for your motor. Change it when you find some oil you can read the label. Nothing worse than riding along worrying about your motor going south. Maybe the oil was specialy formulated for yak cart wheel bearings? I have seen the results of yamaha 600 and 660 motors run low on oil here at the shop where I work. Here in the USA they use the same basic motor to power 4 wheelers. Trust me you don't want to have a oil related failure.

it'll be fine. ignore all the pretty packaging, you're looking for 20/40 for hot weather and possibly 10/30 for colder climates. SE. SF or SG spec. Well, that's what the manual says. Whatever you can get your hands on (within reason) is better than nothing.

try not to mix mineral and semi-synthetic, as they will seperate.

All oils should have the spec on the back, the rest of the writing is marketing and is foreign in anyones language :)

It is very simple to answer - use only oils indicated for motorbike use, if your motorbike has wet clutch ( most of them included ).
Regards,
AnteK, XTZ 660

"use only oils indicated for motorbike use,"

that's what he's saying though, there is no motorbike specific oil available. Buying a can of oil with 'motorbike' written on it is a luxury item in a lot of places.

From what I have read elsewhere the car specific oils to avoid are the thin 0-40, and 5-30 types, as these tend to have the friction modifiers in that can cause clutch slip. I run a Yamaha XT225 serow on 10/40 semi synthetic car oil without problems. I have friends who are using the same oil in a couple of BMW GS650's and a Triumph Tiger and Thunderbird, a neighbour also uses it in his Honda CBR600 and Suzuki GSXR that he races, again without problems. A lot of what is said about using m/cycle specific oil is all part of a markeing strategy. Also the 'car' oil is usually a fair bit cheaper than the stuff 'packaged' as m/cycle oil.

Oh No , not an oil thread !
 

I use Amsoil and Mobil 1 in my vehicles and bikes . Both will mix with mineral oils [and I have done it on several occasions ] without causing damage .I imagine the majority of synthetics will also be ok . Synthetic oil is after all - just oil - without the impurities that are found in refined crude oil .
I know several guys who use automotive Mobil 1 15/50 in their bikes [mostly Nortons] without problems .
Most car type oils and diesel type oils can be used in a bike if they are of the SG /CF type .
The oils to avoid would be the SJ and similar which will have anti friction additives , lower viscosity and other dooberyferkins just to help modern cars be more frugal with fuel .
In a pinch , any oil is better than no oil , but look for the SG [or lower category] and a viscosity of 10/40 or 20/50 and you should be ok .

-----My 2 cents worth , no warranty implied , your mileage may vary , may cause flatulence ------------------------------------------------------

Dodger

Clean engine oil meant for a car is better than not changing it at all. Just change it a bit more frequently.

As far as I understand car and bike oils have gone their separate ways in recent years and that the problem is more than just getting clutch slip when using car oil. Below is an explanation I read on a classic car site (original from marcfuller)

"For the last 10 years API graded passenger car oils have been formulated with increasingly reduced zinc dialkyl dithio phosphate (ZDDP) amounts. Particularly the recent SL/SM grade oils of the last 3 years. The reason that ZDDP is important is that it is about the only high pressure lubricant available capable of providing lubrication between the cam lobe and tappet. The reason that the SL/SM oils can forgo a needed level of ZDDP is that newer cars use roller tappets, rather than the flat tappets in our Elans. The reason for reducing ZDDP is the zinc and phosphate reduce the life span of catalytic converters.
Fortunately, most racing oils and motorcycle oils (BMW motorcycle oil may be an exception), and diesel engine oils have the higher levels of ZDDP that were present when flat tappets were the norm"

It seems that these oils are not compatable with the way bike engine cam gear works and can lead to more rapid cam follower wear. Probably not a problem if you just need something for the short term but if you use it year in year out it may shorten engine life.

I notice in my Harley manual it says if you can't get the Harley recommended oil to use a good quality diesel engine oil since it is a better match for an air-cooled engine.

note specs
 

the level of zinc -can- be higher in 20-50 grades as this is too thick for newer car engines that need lower levels for their catalytic converters, so is exempt the limits. all othergrades are 12 ppm or less (sg, 10ppm sf/sl). note unlike most things the grade denoted on the can is a -maximum- grade. ie if it says sg only then is likely to be better than one that says sf sg and sl as it cant comply fully with sg if it meets sf and or sl. try to avoid too wide a range eg 0-40 . and yes go find a diesel oil such as shell rotella 15-40. sg rated.. note this info is biased for air cooled engines.