10W-50 Oil

Godzilla · 08-24-2010, 12:05 PM

I have some Silcolene 10W-50 Fully synthetic oil that I have left over from my last bike. Is this OK to put in the S1000 or do I need to get some of the 5W-40 like it says in the riders manual.

What do these 2 numbers represent, I have an idea it is to do with temperatures and viscosity, but not exactly sure.

TIA

crabman · 08-24-2010, 12:35 PM

The manual calls for 5W-40 OR 10W-40. You should probably stick with what the manual calls for. The numbers represent viscosity (thickness, ease of flow) at cold and hot temps. The first number is the viscosity cold and the second when hot. The lower the number the thinner or easier it flows. Going thicker (higher number) can slow down the return flow of the oil in the engine.

**viperclaw** · 08-24-2010, 09:53 PM

Do not use 50 in this motor. 40 is the thickest you want to run.

poiteau · 08-25-2010, 05:15 AM

Hello,

10/40 is OK, so 10/50 is too. The most important point is the compliance with JASO MA2 norm

markjenn · 08-25-2010, 05:58 AM

This oil will probably work fine, but it is not optimal, especially if you ever operate the bike in cold weather. Viscosity recommendations represent what the mfg views as the best overall compromise so deviations seldom cause immediate problems, but unless you're operating the bike in some unusual circumstances, it is best to stick with what is spec'ed.

The first number represents the viscosity at low temperature; the second at high. To counter-act the oils natural tendency to thin out at high temps, you want the oil to behave as a low-vis oil when cold and as a high-vis oil when hot. This would lead you to think that a wider range is always better, but to make oils have this dual personality requires additives (called viscosity improvers) that don't do as good a job lubricating as the base oil stock.

Again, everything is a compromise so there is no perfect oil, but BMW thinks 5W-40 or 10W-40 does the overall best job.

-Mark

Phil96 · 08-27-2010, 07:39 PM

But will 10-40 be OK in these 115 degree Vegas summers?

markjenn · 08-27-2010, 07:46 PM

Quote:

Originally Posted by Phil96

But will 10-40 be OK in these 115 degree Vegas summers?

The bike is water cooled and thermostatically controlled so the oil shouldn't see much more heat in 115 than it does in 90.

Where a heavier oil might pay off is sustained high-speed running at big throttle openings. If I was doing 140+ for a few hours, I'd feel more comfortable with something heavier than 40W in there. The problem is that to get a 50W oil you either need to sacrifice some cold-startup wear with something like a 20W-50 or you have to accept more VI's in something like a 10W-50. And one problem with the VI package in a super wide-range oil like 10W-50 is the VI's break down relatively rapidly compared to the base stock and the oil loses viscosity. So after 3K miles, a 10W-50 might be 10W-25. whereas a 10W-40 might be 10W-35.

- Mark

Phil96 · 08-27-2010, 08:01 PM

Quote:

Originally Posted by markjenn

The bike is water cooled and thermostatically controlled so the oil shouldn't see much more heat in 115 than it does in 90.

Where a heavier oil might pay off is sustained high-speed running at big throttle openings. If I was doing 140+ for a few hours, I'd feel more comfortable with something heavier than 40W in there. The problem is that to get a 50W oil you either need to sacrifice some cold-startup wear with something like a 20W-50 or you have to accept more VI's in something like a 10W-50. And one problem with the VI package in a super wide-range oil like 10W-50 is the VI's break down relatively rapidly compared to the base stock and the oil loses viscosity. So after 3K miles, a 10W-50 might be 10W-25. whereas a 10W-40 might be 10W-35.

- Mark

Thanks, for interesting and prompt response.
Cheers,
Phil

Godzilla · 08-28-2010, 08:07 AM

Thanks for that info, now when ordering oil I guess I get fully synthetic, but does brand make any difference? My last bike was a Daytona 675 and that seemed to burn much less oil if people were using Silkolene than Motul.

markjenn · 08-28-2010, 01:41 PM

Quote:

Originally Posted by Godzilla

Thanks for that info, now when ordering oil I guess I get fully synthetic, but does brand make any difference? My last bike was a Daytona 675 and that seemed to burn much less oil if people were using Silkolene than Motul.

If you're ordering synthetic boutique bike oils like Silkolene or Motul (probably at $15+ a qt!), they're all so good, I don't think it makes much difference. I'd be sure the oil is pure ester-based and MA2 rated. I think BMW now has a high-end 5W-40 synthetic too, so you could play it super-safe and just put this in it.

- Mark