The International CBX Owners Association

I have noticed quite a few forum members have opted for Mobil 1 15W-50 engine oil.

The closest I can find in this part of the woods is "Mobil 1 5W-50 fully synthetic".
Says on the bottle, meets: API SJ/SL/SM/CF; ACEA A3/B3, A3/B4

Is there a reason I should not use this? I can't think of one, but any suggestion would be very welcome.
thanks, Aris

Aris: I see many people cringing and saying "please, not another oil thread" and you will probably get as many telling you it is O.K. to use, as those who will say no.
You may consider the following: Automotive oils are going through a perpetual change and adjustment trying to comply with environmental rules and regulations as well as with requirements by car and engine manufacturers. As a result, most automotive spec motor-oils today feature additions on one side and lack of components on the other that may not be suitable for use in a 30-year old motorcycle.
I can not and do not want to speak for others, but in the CBXes, I do not use automotive spec oil because there are a few potential problems: The lubrication of the flat lifters which CBXes have, due to the lack of zinc-based additives, wet clutch performance due to friction modifiers in auto oils, the degradation of the multi-grade oil caused by the transmission of the motorcycle and last not least very specific formulations as not to be harmful to catalitic converters.
I use automotive spec oil only in those of my bikes that have separate engine and transmission oil. In all others, I use motorcycle specific, single grade oil.
I think, everybody should use the kind of oil that they like or have the best experience with or want to use for any other reason.

As far as you using a 5-50 as opposed to a 15-50, there shouldn't really be much difference. The 5-50 would give you a better oil performance at colder ambient temperatures and start-up. I am surprised, howver, that you get a 5-50. Most of the Mobil 1s I have seen are 5-30 or 15-30

A comment, to use as anyone sees fit, relative to multi-vis oils. Multi-vis oils/lubes are a base oil with additives to increase viscosity as the temperature increases. As these oils are used, the additives are gradually broken down such that the oil degrades back towards the base oil. The base oil is the low viscosity. In motorcycles with common engine-transmission, the shear action of the transmission gear teeth tends to accelerate this breakdown. How fast, hard to say. It depends upon temperature and load. Eventually, though, with multi-vis, you will be running a thinner oil than yuo started with. So, are multi-vis good or bad, that's an individual decision. Which ones....? Typically, synthetics do not breakdown as easily/quickly as 'natural' oils. You take it from here.

Guys:
I most certainly DON'T want to start another long thread . My question was simple and innocent; I looked and couldn't find Mobil 1 15W-50, which understand quite a few Forum members use and is good enough for me. The closest I can get my hands on over here, is Mobil 1 5W-50.

My rebuilt engine is currently on Texaco Magnatec 10W-40 and I have been experiencing low indicated oil pressure when the bike is really hot, ~45 PSI @ 4K RPM and ~10 PSI at idle (on a cheapo gauge though). When cold, indicated pressure is ~75 PSI.
Before I look deeper, I thought I would use a thicker / better oil, as above, and see what happens.

Thanks, Aris

Preston Marks recently published a video of him verifying proper pressure from an oil pump. Apparently it can be adjusted. I can't find the video on YouTube, perhaps it's offline, but it was interesting.

N.

Kool_Biker wrote:Guys:
I most certainly DON'T want to start another long thread . My question was simple and innocent; I looked and couldn't find Mobil 1 15W-50, which understand quite a few Forum members use and is good enough for me. The closest I can get my hands on over here, is Mobil 1 5W-50.

Thanks, Aris

Aris: I tried to touch on this a little. One reason, you can't find Mobil1 15W50 may be that Mobil doesn't offer this. I have never seen it. In our area they only sell 15W30

Thanks Mike, all of your inputs are noted, valued and hugely appreciated, as you know

I will try to swap the oil in a couple of days, as for some reason I mistrust the Texaco Magnatec.
Then, I will look seriously into the matter, so any input will be appreciated.

BTW does anybody know the pressure below which the engine oil light comes on?
It never comes on with the engine running, even with an indicated ~10 PSI on idle (very hot). Is this right?

Thanks, Aris

Aris:
Do you have access to Honda's brand of oil? They offer a full synthetic in 20-50 and 10-40. It's usually about the same price as Mobil 1 over here. It's as good as any and is m/c rated.

Dave

Wal Mart carries Mobil 1 15/50 at $24.00 for a five quart container.
Best,
Phil

Aris, your pressure changes between cold and hot are not too extreme. What do you have at 1500 - 2000 rpm? While I can't speak from personal experience with an X, I should think it should be near the 40 - 45 level based on automotive experience. Idle between 10 - 15 won't hurt: no load. Maybe, Dave McMunn will have some first-hand info for these numbers.

FalldownPhil wrote:Wal Mart carries Mobil 1 15/50 at $24.00 for a five quart container.
Best,
Phil

Interesting! I need an oil change on my Corvette and this would be the perfect oil. So I ran to WalMart right after work last night. They do not have it. Went on the Mobil 1 web-site and it does not show availability of 15W50 in any store within 50 miles of my zip code. They may have a product distribution strategy that is based on regional requirements.
That may be the reason Aris can't get it.

Sorry about that Mike. Wal Mart carries a wide range of Mobil 1 out here.
Best,
Phil

FalldownPhil wrote:Sorry about that Mike. Wal Mart carries a wide range of Mobil 1 out here.
Best,
Phil

Except the motorcycle specific Mobil 1 oils.

http://www.mobiloil.com/USA-English/Mot ... 0W-40.aspx

There's lots of great motorcycle oils out there Aris. I'm a little surprised no one has mentioned the big oil divide hen Japan got all flustered with the oils of the past 5-10 yrs and came out with their own JASO specifications to cut through all the hype and bs out there that was ruining too many Japanese engines.

All of this occurred as more and more wear and anti-scuffing additives were removed from all the "new and improved" oils across the market .......even motorcycle oils...... mostly American brands.

I won't get into all the technical jargon as this would bore you and everyone else to death.....but the bottom line is what the best oils are today for bikes. These oils are clearly marked "API SG and JASO MA" rated oils. http://en.wikipedia.org/wiki/Japanese_A ... ganization

The bottom line is any MOTORCYCLE oil you can find with "API SG and JASO MA" on the can/bottle is a top oil and what you want to use in your motorcycles.

Personally I run Mobil 1 4T 10w--40 SG/MA rated 100% synthetic oil in my CBX's because it's readily available to me (even Wal-Mart has it).....and it costs 30%--50% less than all the boutique SG/MA oils offered by other oil companies.

For my other bikes that call for a 20W--50 I run Mobil 1 "V-Twin" SG/MA rated 100% synthetic oil for the same reasons.

btw..... when I got my 80X it was "pseudo" chopper and seemed to have done too many laps at Burger King and it had been over-heated many times, hence the valve stem seals had hardened..... not to mention the oil hadn't been changed for quite some time due to the 6/1 exhaust that blocked the oil filter and drain plug. Therefore the bike smoked and used a bit of oil....about a quart every 1000 miles.

Being a believer of full synthetic oil for years and with great results with it..... I changed the 80x oil to Mobil 1 and over the next few months of riding the smoking stopped and the oil usage went down to about 1/2 quart every 1000 miles.

So there you have it, use what you want (dino or synthetic.....but at least check that it says "SG and MA" rated motorcycle oil on the bottle.

$.02

After a rebuild, always run a mineral based oil, not a synthetic. However, once the motor is run in, synthetics are a preferred choice as long as they do not interfere with your clutch. I have run Mobil 1 5w-50 in my Harley for years. No problem with clutch slippage, no extra oil leakage and although the oil pressure is reduced, so too is the temperature of the oil....by about 20 degrees in the real hot weather (over 100).

The Harley engine however is totally separate from the transmission unlike the CBX. For this reason I would not run this oil in my CBX or any transmission as it will not have the anti shear additives that a good motorcycle oil will have. I use Motul semi-synthetic for my Hondas and full synthetic for the Ducati. When chosing an oil, for an air cooled engine, you are always best to get something in 50 weight as this oil will have phosphates (ditto if you run an old VW). For liquid cooled engines you do not need a 50 weight and 30 or preferably for a bike 40 weight is fine. I do not care much about the winter weight as I do not run my bikes in sub zero C temperatures so a 20w is fine in my book. With a good multigrade the oil should theoretically flow the same at 10 C whether it is a 0w or a 20w.