Oil types?

[magicmonkey]

I'm about to do an oil change and I've found that I've got nearly enough mineral oil and nearly enough synthetic oil but not enough of one or the other to do the job. Can I just mix them or should I be buying a load more oil and getting it all the same?

Also, WTF is with motorcycle oil? how is it different to normal oil? The stuff all lubricates engines so I can't see that there would be any real difference between the 2 but I'm wondering if I might be barking up the wrong tree with that one ...

[Blackbird]

The short answer is no, don't mix oils or you ruin their individual characteristics and run the risk of shortening the life of your motor at the same time. If you've done reasonably high k's (say 50,000 km+ or less on a high-revving motor), using a fully synthetic oil for the first time at that distance; you run the risk of oil seal leaks as synthetic is a very efficient dirt scavenger and can take carbon and other residues off seal faces causing leaks (it did on my wife's first MX5).

One of the major differences with motorcycle oils is that they tend to avoid certain components of the additive package which car oils have. This is because most bikes have wet clutches and car additives can make them slip. Also, some bike oils have an additive to reduce the effects of oil shear (early breakdown of the oil) due to higher revs than cars. Hope that answers your questions anyway.

[magicmonkey]

The short answer is no, don't mix oils or you ruin their individual characteristics and run the risk of shortening the life of your motor at the same time. If you've done reasonably high k's (say 50,000 km+ or less on a high-revving motor), using a fully synthetic oil for the first time at that distance; you run the risk of oil seal leaks as synthetic is a very efficient dirt scavenger and can take carbon and other residues off seal faces causing leaks (it did on my wife's first MX5).

One of the major differences with motorcycle oils is that they tend to avoid certain components of the additive package which car oils have. This is because most bikes have wet clutches and car additives can make them slip. Also, some bike oils have an additive to reduce the effects of oil shear (early breakdown of the oil) due to higher revs than cars. Hope that answers your questions anyway.

nice one, exactly the information I was after, thanks for that

[Blackbird]

No worries. If it's for your GN250, the something like Motul 5100 semi-synthetic is as far as you need to go. Castrol Power 1 GPS semi-synthetic is cheaper because they sell it at Repco!

[magicmonkey]

No worries. If it's for your GN250, the something like Motul 5100 semi-synthetic is as far as you need to go. Castrol Power 1 GPS semi-synthetic is cheaper because they sell it at Repco!

Nah, it's for the ZXR, the GN had a change about 1000 k's ago so there's plenty left on that one.

I was edging towards using the synthetic oil in the the ZXR as I'd heard it's better but just didn't know how it's better, for now it sounds like I'd best stick to mineral though

[Blackbird]

Nah, it's for the ZXR, the GN had a change about 1000 k's ago so there's plenty left on that one.

I was edging towards using the synthetic oil in the the ZXR as I'd heard it's better but just didn't know how it's better, for now it sounds like I'd best stick to mineral though

As long as you drain your mineral oil pretty well first, it would be quite safe to go to semi-synthetic as semi-synthetic is a mix of base stocks. It will also provide better protection than straight mineral on a higher revving motor like the ZXR. I was involved with early trials of Mobil 1 on some of the vehicle fleet which our company owned. Compared with the multigrade which we previously used, the metal wear debris in the oil at oil change time was about 3 times less with synthetic than the multigrade (measured by spectroscopy). There's lots of factors which affect wear rates and suitability, but it's an indicator that you get what you pay for.

[p.dath]

I'm about to do an oil change and I've found that I've got nearly enough mineral oil and nearly enough synthetic oil but not enough of one or the other to do the job. Can I just mix them or should I be buying a load more oil and getting it all the same?

Also, WTF is with motorcycle oil? how is it different to normal oil? The stuff all lubricates engines so I can't see that there would be any real difference between the 2 but I'm wondering if I might be barking up the wrong tree with that one ...

This is outside of my area of knowledge, but I was told you can mix either mineral or synthetic with semi-synthetic, but don't mix mineral with fully synthetic.

[magicmonkey]

ok, here's another one, the manual says I should be using se, sf or sg grades with a viscosity of 10/40 - 10/50 - 20/40 - 20/50. Seeing as I'm going to buy a new bottle of oil anyway, which one of those should I choose? I understand the whole viscosity thing but the grades are something I'm completely in the dark about (I also don't know how to actually choose a viscosity although I know what the numbers mean)

[Blackbird]

I'm presuming that your ZXR manual is a few years old now as most good oils are now SJ rated. If you go for the Castrol Power 1, it's SJ 10W 40 and I think Motul 5100 is too from memory. Absolutely fine for your bike so don't sweat it!

SE, SF and SG API categories have been surpassed and can effectively be considered obsolete. SJ oils have a lower phosphorus content than SH, principally to further reduce contamination of catalytic converters from carry-over. I'd guess that virtually any major brand of automotive oil is probably SJ rated by now if they want to keep market share.

[magicmonkey]

yeah, the manual is ancient, barely readable in many places too! Did a quick google and managed to uncover that they were obsolete but not what replaced them, seems you're even better than google mate, nice one

[vifferman]

One of the major differences with motorcycle oils is that they tend to avoid certain components of the additive package which car oils have. This is because most bikes have wet clutches and car additives can make them slip. Also, some bike oils have an additive to reduce the effects of oil shear (early breakdown of the oil) due to higher revs than cars. Hope that answers your questions anyway.

There was a guy on the old VFR forum who was an oil engineer, and who did extensive work on oil testing. His studies showed that the Mobil synthetic for cars was perfectly fine for use in bikes, and in fact more betterer, as it contained a better additive package, and was usually able to be bought cheaper! He found no evidence whatsoever of it causing clutch slippage, contrary to what has long been espoused on Teh Interdweeb.
Other than that, he opined that the best value oil for bikes was a reasonable quality diesel oil, as it was usually cheap (especially in bulk packs) and had exceptional longevity and detergent properties, due to the harsh demands of diesel engines.

[Blackbird]

There was a guy on the old VFR forum who was an oil engineer, and who did extensive work on oil testing. His studies showed that the Mobil synthetic for cars was perfectly fine for use in bikes, and in fact more betterer, as it contained a better additive package, and was usually able to be bought cheaper! He found no evidence whatsoever of it causing clutch slippage, contrary to what has long been espoused on Teh Interdweeb.
Other than that, he opined that the best value oil for bikes was a reasonable quality diesel oil, as it was usually cheap (especially in bulk packs) and had exceptional longevity and detergent properties, due to the harsh demands of diesel engines.

'ello Ian - long time no hear!

Tribology was part of my responsibility before I became a layabout! I dealt directly with the Mobil engineers as they were our preferred supplier for industrial and automotive lubricants. It was actually their people who made the comment about not using Mobil 1 car oil in wet clutch applications (I used it in my Beemer K100 because it was a dry clutch) and their Mobil 1 4T Racing for bikes is the same as Mobil 1 (car) but with one element of the additive package removed so I guess they had some basis in theory for the difference, even if not in practice. Potential litigation is a wonderful incentive for a conservative approach

For slower-revving engines, diesel oil may be ok but for higher revving engines (bikes in particular), high rotation speeds effectively increases shear at the molecular level, decreasing viscosity and wearing the oil out. Again, that's from a theoretical perspective but for road use at least, the old engineer may be right.

So you're using reasonable quality diesel oil in your Vifferrari?

[porky]

Blackbird, dont want to high jack this thread but you seem to be the man on lube. VTX 1800 book gives 80 SAE hypoid for the rear drive. Emptied out today and its red ?? What brands have a red gear oil. I run ATF in 2 stroke boxs,which is red. Is it possible its ATF?? Your thoughts please. (Last oils were done under warranty service from dealer>)

[Blackbird]

Blackbird, dont want to high jack this thread but you seem to be the man on lube. VTX 1800 book gives 80 SAE hypoid for the rear drive. Emptied out today and its red ?? What brands have a red gear oil. I run ATF in 2 stroke boxs,which is red. Is it possible its ATF?? Your thoughts please. (Last oils were done under warranty service from dealer>)

Sorry to be a disappointment - I know how lubricants work, not brands and their dyes

[porky]

No disappointment at all. Will cut past the dealer today and see if i can pull the records.