Car engine oil v Mcycle engine oil.

[boxerscott]

Why bother paying 3 x as much for your boxer engine oil?

[bikesnbones]

Why bother paying 3 x as much for your boxer engine oil?

Can you be more specific.
The "boxer engine oil" I use costs about the same as the equivalent quality car oil.

[conkerman]

As long as it meets the apropriate API spec its good to go.

From memory its API SF, pretty much anything will meet this nowadays.

I would just adjust the drain interval for posher oils than the bog basic stuff.

[Corvus]

As long as it meets the apropriate API spec its good to go.

From memory its API SF, pretty much anything will meet this nowadays.

I would just adjust the drain interval for posher oils than the bog basic stuff.

Does the API rating determine the viscosity rating and whether it is mineral, semi synthetic or fully synthetic?

Wet clutches figure prominently in "motorcycle oils", and isn't consideration given to this in determining compatibility? Not an issue pertaining to boxers, until very recently.

[conkerman]

The API grading is a set of generic tests that do not specifically require certain viscosity and base oil chemistry. They are seen in the industry as the lowest bar. The SF approval is described as for engines from pre 1988! The boxer is not fussy for oil.

Although the later API approvals may require a beefed up base oil to pass. The latest approval (SN) has improved sludging and piston deposit performance.

As a very sweeping generalisation. Changing base oil chemistry tends to affect long term and extreme condition performance.

For the UK I don't think you can go far wrong with a 10/40 semi.

[Corvus]

The API grading is a set of generic tests that do not specifically require certain viscosity and base oil chemistry. They are seen in the industry as the lowest bar. The SF approval is described as for engines from pre 1988! The boxer is not fussy for oil.

Although the later API approvals may require a beefed up base oil to pass. The latest approval (SN) has improved sludging and piston deposit performance.

As a very sweeping generalisation. Changing base oil chemistry tends to affect long term and extreme condition performance.

For the UK I don't think you can go far wrong with a 10/40 semi.

Would it be fair to categorise the base oil chemistry into three basic groups? Mineral, semi synthetic and fully synthetic? Or do we need to look deeper into this?

Then, would it be fair to say that, when comparing prices, we need to have three factors in line. The base oil chemistry type, the API rating and the viscosity grade? All assuming that we have checked the manufacturers recommendations for these three factors in the first place?

As long as those three factors all compare then we can simply buy the best offer?

Is it that simple?

[conkerman]

You can pretty much ignore the API as long as it is SF or greater.

For example the cheapo oil from halfords is API SL.

Viscosity choice is driven by climate there is generally lots of oveelap in the bands, so you have options.

For baseoil chamistry, in my opinion going posh allows you to extend the drain interval if you want.

So, it is even simpler than you think.

[Twinspark]

Boxers seem to be happiest on 20w50 - I've just swapped to this from my usual 10w40.

Unfortunately, the cheap Halfords 20w50 Classic oil is only SE spec., so I ended up buying some Harley tractor oil from the local upside-downy head bike shop.

[Boxered]

I have just had cause to replace my engine oil between services, and I had trouble finding 20/50 semi-skilled
tried online, ebay, opie etc
eventually found it a mile away at my local multi franchise dealership, 4l Putoline 20/50 Vtwin power for £29, much more than I expected to pay, but hey, they had it on the shelf and that counts for a lot!

Steve

[Twinspark]

My tractor oil was £24.95 and they threw in a filter, too.

[conkerman]

Halfords were doing 10/40 and 5/30 for a Tenner for 4 litres.

Bargain.

[boxerscott]

Halfords were doing 10/40 and 5/30 for a Tenner for 4 litres.

Bargain.

Good Man, bang on the money, wot I bought less discount with trade card and semi synthetic at that! Lot to be said for dry (cough) clutch but we still have to buy gear oil. So why buy motorcycle specific for a bmw boxer engne? it ain`t a Scooby doo what it is motivating

[conkerman]

If I didn't have a shedload of oil in the garage from a mate in the trade I would buy a couple of those.

[Corvus]

The wikipedia article on API rating from SJ on, regarding Phosphorous content is interesting. Are they saying that oils pre SJ could actually resist wear better than current ones, all else being equal?

They say that speciality oils for performance engines go backwards in their API grade. If I've understood it right.

[conkerman]

Chemistry time!

Phosphorous comes from ZDDP Zinc Dithiophosphate. This has been used for years and years for its anti-wear properties.

Phosphorous is poisonous to exhaust after treatment, so there has been a move reducing levels of ZDDP to allow smaller after treatment systems to be used. Although the move towards low SAPS (Sulphated ash, Phosphorous and Sulphur) lubricants and lower CO2 (low viscosity) means that the oil is under a bit more stress, as such the additive packs in the lubricant have been improved to maintain lubrication performance.

Again, I would not think too much about it.