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Isn't the wording on that API document slightly misleading? Instead of (for example):-

"SJ --- Current --- For 2001 and older automotive engines."

should it not read:-

"SJ --- Current --- For 2001 (and earlier) automotive engines." ?

The first statement seems to imply that 'SJ' is good for engines specifically manufactured in 2001 but also for some unspecified old 'smokers' from a bygone age (No not you Dai. You can sit down again mate ) whereas what they mean is engines built up to and including 2001. I'm giving myself a headache here.

Done it once, ruined the clutch. Never again.

It is the Molybdenum friction modifiers that wreck wet clutches. Non Moly ones are available but tend to be more expensive.

I still wouldn't use anything without JASO MA approval, but horses for courses.

conkerman wrote:Done it once, ruined the clutch. Never again.

It is the Molybdenum friction modifiers that wreck wet clutches. Non Moly ones are available but tend to be more expensive.

I still wouldn't use anything without JASO MA approval, but horses for courses.

JASO MA in me wet clutch blade.

I`ll never understand why people just don`t use what the manufacturer recommends, why go to all the trouble of research etc and faffing around with cheap oils which may or may not be of the right spec...for what?

If you change your oil for example every 3K, saving a fiver or whatever over 3k miles is irrelevant, just stick the proper stuff in and forget about it?

Oil is the `lifeblood` of your engine, if you love your bike that much what`s the point in saving a couple of quid every six months, it all pales into significance when you work out what you will spend in fuel over that time period?

I think the point is that some manufacturers get it badly wrong (yes, Alfa Romeo, I'm looking at your silly piss-thin Selenia) or specify something unobtainable (and now I'm looking at BMW as they spec. some really odd oils).

We all want to make life easy - so will try to get away with what's available locally, or from somewhere we regularly visit. Which is why I have a shelf in my garage full of Halfords oils - 10/40 usually - and in both car and bike specifications.

Hinckley man wrote:I`ll never understand why people just don`t use what the manufacturer recommends, why go to all the trouble of research etc and faffing around with cheap oils which may or may not be of the right spec...for what?

'cos like I say, they use loads of this at work on the maintenance side and an oil change will cost me pence instead of £30.00 a 'pop' if it's suitable. And the consensus seems to be that it is.

The piston speed of an engine determines the type oil to be used eg mineral, part synthetic or fully synthetic. Basically that means the faster the piston speed the more complex the oil development because you would like to have longer strings to encourage lubrication under extremes. That means that the stroke determines the piston speed and hence the max rpm for a particular design. Nothing wrong with using budget or top notch oil as long as it conforms to the original spec. As I said before, the quality of the oil filter is very important. It is important that the fluid is clean to prolong the life of the engine. The operating environment is a factor that will shorten the life of the oil eg dusty, humid and hot or extreme cold conditions. The manual will state the operating conditions and the alternative oil spec for other conditions. It doesn't say brand A, just the spec and that is an international standard.

How many of you remember what was said by the oil companies when they first came out with synthetic oils?
They said that these new oils were so slippery that you should not use them in a new engine as it will not run in if they were used
However today they say that your engine will run in with them
The only common sense in a manual i have ever seen about oils is in the harley manual where they state if using synthetic oils you can double the milage between changes for both the filter and oil

Change your oil and filter on a regular basis and all will be good synthetic oil won't sludge so all the crap will travel round your engine until it gets caught by the filter with a mineral oil a lot of crap gets caught in the sludge

What oil to use? What ever has been used from new just about the worst thing to do is use mineral oil for 25000 miles then switch to synthetic it will wash out all the sludge and block your filter if you do want to switch from mineral to synthetic be prepared to change your oil filter every few miles at first to catch the sludge before it causes any harm
If you want to switch from synthetic to mineral oil be prepared to change your oil more often

el-nicko wrote: 'cos like I say, they use loads of this at work on the maintenance side and an oil change will cost me pence instead of £30.00 a 'pop' if it's suitable. And the consensus seems to be that it is.

well, I guess that`s different?......

All I meant was, If you change your oil every 6k for example ( and theres no reason to suggest it needs it more frequently if a good quality oil is used, granted we all change it more often!) @ 40mpg that`s 150 gallons, or 675 litres which at £1.35 a litre is £911. The cost of oil is not your problem..

Now, if you can figure a way of getting the fuel figure down to pennies a litre, please tell me..

To be fair Dai even new engines that have much much tighter tolerances than when synthetics were introduced are a bit too well protected and high oil consumption can often be relieved by running for a short time with a low spec oil. But the advice about switching after long term use is good.

Pistonspeed is one of the indicators you can use to determine what oil to use, more important though is the stuff that is hard to see, things like shear rates and the presence of any areas of high thermal stress.

As stated probably many times before, as long as you use a suitable lubricant (example API SF) and change it suitably often, you should be in good shape.

We are talking about old fashioned air oil cooled engines here
The modern water cooled engines are a different kettle of fish they are built with such tight tolerances that many need fully synthetic oils

Older engines didn't even need multigrade oils then along came the Japanese their engines were built to tolerances that they needed a thinner oil when cold and a thicker oil when hot so the multigrade oils were born

These Japanese engines were so well built compared to the British engines when they left the factories they were shagged by the time they reached the tolerances that the British engines were made with this is the reason they had a bad name at the time the oils we were using in them could not get through the tiny spaces when they were cold

We all remember the kawasaki gpz 305 chocolate camshaft thing when in reality we used the wrong oil in them run them on synthetic there will be no problem but synthetic oils were not available over here (well they were but not on the highstreet )

What oils do I use? In the cars full synthetic the trike gets cheap 20/50 the bikes get 15/40 mineral oil

It's a very interesting subject and I would like to thank everyone for their views

Cheers all Dai

Always an interesting conversation topic. And it seems most are in broad agreement, which is unusual.

I am with Hinckley man on this. I stick to what BMW recommend, mostly for peace of mind. I have no doubt that other oils are more than adequate and money could be saved if need be, especially considering our oils don't have to be suitable for gearbox or wet clutch use.

Costs are reasonable. I normally buy from Opie when they have a Castrol offer on, so its not worth the effort to save a couple of quid for me.

Herb wrote:I am with Hinckley man on this. I stick to what BMW recommend, mostly for peace of mind. I have no doubt that other oils are more than adequate and money could be saved if need be, especially considering our oils don't have to be suitable for gearbox or wet clutch use.

Costs are reasonable. I normally buy from Opie when they have a Castrol offer on, so its not worth the effort to save a couple of quid for me.

Me too, sure the other stuff would probably be fine, sure they're an old engine that doesn't put too much stress on it's oils etc etc.

But I like the peace of mind of knowing it has the right stuff in it, and my step Dad (who was a senior Honda motorcycle technician) drummed into me that oil is easier to change than crankshafts ... and if it goes pop it's 'cos of my abuse not the oil... maybe