Oil question- sorry

[Jethro]

I hate to bring up the old oil issue again, but... I usually buy Castrol Syntec, but the previous owner of my ney bike said he used Mobil 1. Whatever he has done has worked so far- the bike runs great. So I go to one of the chain auto stores and look for Mobil 1. They don't have any in 10-40 weight. I go to another store and find that they also do not have Mobil 1 in 10-40- only 10-30 like the other store. So I check for Castol Syntec- no friggin' 10-40 either, only 10-30. So I say f-it, and buy the Mobil 1 10-30.

Can I use 10-30 in my bike? I should know the difference, but can someone tell me in plain english what the difference between 10-30 and 10-40 is?

I'm stupid.

[Dink]

the weight (thickness) of the oil at temperature,when cold the oil has the "weight" of a ten weight oil (water is 0 weight BTW) as it heats up it thickens, so as at 100 C it has the thickness of a thirty weight oil.
It shouldn't be a problem to run it , but I would keep my eyes open for 10W40 and when you find it do an oil change, buy two bottles when you do find it , then you have enough for at least one more change whilst you look for it again.
Dink

[redliner1973]

He is probably referring to 'red cap' 15w-50. Don't use the 10w-30...

[KennyJ]

Most run the red cap 15-50w. I run the same in my FJ1100. It actaully makes a difference from the Valvoline synthetic I tried. I can't believe it would make a difference, but the clutch is smoother, less creep, and shifts a tad easier. I am sold on the Mobil 1.

My original owner said it was all he ran.

Kenny

[first timer]

run the red cap mobil 1 the 15w-50. i use it in my 550 and it is very happy.

-ryan

[redliner1973]

Also, the 'red cap' 15w-50 is on the low side of the CST for viscosity, it is actually closer to a 10w-40 oil.

[Jethro]

He is probably referring to 'red cap' 15w-50. Don't use the 10w-30...

No, it's definitely 10-30 oil. Is it that much of a differrence? I thought 10-40 was pretty standard, but today I couldn't find a single bottle of full synthetic 10-40.

[redliner1973]

There is alot of difference other than just the weight. While I am sure your friend has had success with using the 10w-30, it is not recommended due to it being too thin, I personally would not use it at all, but if I did, I would do a UOA to make sure it is not killing the engine. Go with the 'Red Cap'

[Anonymous]

It isn't really about the weight. It's about whether or not the oil is 'Energy Conserving'. Manufacturers add friction modifiers to energy conserving oils to make them more slippery, reduce friction, and give you better fuel economy. That's great for cars, but for bikes with a wet clutch, bathed in engine oil, that's bad news. Your clutch will not be happy, and could likely start slipping.

Look for a seal/circle on the back of the oil bottle (if in the US) that says 'API Service SL/etc', with the weight in the middle (e.g. SAE 10W40). If that seal also includes the words 'Energy Conserving', don't use it in your bike. If not, it's likely that you can use it.

As others have said, the Mobil 1 15w50 viscosity is the only Mobil 1 that is not energy conserving, thus safe to use in your bike.

[Jethro]

Got it now. I found the 15-50 oil and bought it. I'll use that from now on. Hopefully this explains why my clutch is slipping.

[saaz]

The problem with the 10W-30 is that it is probably energy conserving, which means that it has those nasty friction modifiers in it that are not at all good for the clutch. 15W-50 is a common choice in the US on all the forums I am on. For any (car) oil just make sure is is not an energy conserving oil.

The bottom line is that energy conserving is bad for the clutch in a bike (except Dukes with dry clutches!) I hav also seen that the 0w-30 (car) oils are not much good as they tend not to be shear stable (ie the gearbox will tear the oil to shreds very quickly!). If you want to use a lighter weight oil get a bike specific oil.

[Anonymous]

This might be really basic, but going with the only stupid question is the unasked one.... So the Castrol Syntec Red Cap 15w50 isn't made specifically for bikes, but will run in our machines just fine?

Thanks...Sam

There is alot of difference other than just the weight. While I am sure your friend has had success with using the 10w-30, it is not recommended due to it being too thin, I personally would not use it at all, but if I did, I would do a UOA to make sure it is not killing the engine. Go with the 'Red Cap'

[redliner1973]

No quesion is stupid...Yes, any 'car' oil will work just fine in a bike - As long as the 'starburst' (energy conserving) logo is not on the bottle. this is usually applies only to 10w-30 weights and below. The main difference between 'bike' oils and 'car' oils is the amount of phosphorous and zinc usage due to effects on catalytic converter issues. Many oils overcome theselimitations by the use of Moly.