Synthetic Oils.

[mallywoods]

Hello again, starting to do my own maintenance, I didn't think we could use synthetic oils in motorcycles because the clutch would not grip, however I am seeing Castrol fully synthetic oil for motorcycles. Can anyone tell me how this is please??? As I prefer fully synthetic and ther is only a couple of pounds difference, 2014 DL650 7000mls.
Thank you.

[Rich:-)]

I didn't think we could use synthetic oils in motorcycles because the clutch would not grip

Not sure of the chemistry but as far as I was aware the above has never been true, or was it once?

You should not use car oils (or any type) which include friction modifiers, but you'll regularly read on some forum somewhere about a bloke who does and has never had any issues.

Semi vs Fully synth... Fully is better but whether or not it is actually required is another issue.

I use semi in my Wee as that is what the manual asks for, I don't do high mileage so will change the oil with low miles travelled and it isn't a highly strung engine.
I use fully synth in my DRZ as that operates in a harsh environment & high temperatures at times due to low speed use off-road.
I use fully synth in my SD as the manual asks for it and it's pretty highly strung engine.

to be honest - If fully doesn't cost much more you may as well I suppose.

[crazyhorse]

Hi

I have used Castrol Power 1 Fully Synthetic 10/40 for over 50k mile on my 2012 L2.
No problems.

Crazyhorse

[greywolf]

As long as the weight is correct, it isn't a problem. Clutch problems come from light weight oil with friction modifiers. If the oil is marked energy conserving, you shouldn't use it. It will be too light and have additives that are bad for wet clutches. You want an oil not marked energy conserving and at least 0W-40. It's the second number that is important. 30 weight on the second number is too light.

Many people's memory of synthetic oil comes from the original Mobil 1 which, besides being a true synthetic, had a light weight and would be considered energy conserving today. It was not supposed to be used until the engine was broken in because it was too slippery to allow break in and it also had a problem of getting past gaskets and seals. Many of today's vehicles come with synthetic oil from the factory. Your first oil change at 600 miles or less can be done with synthetic oil as long as it is not marked energy conserving and its second number is at least 40.

Today, synthetic is more of a marketing term. It can be made from petroleum stocks and still be labeled synthetic for example. Just avoid energy conserving oils. https://www.calsci.com/motorcycleinfo/Oils1.html

Synthetic oils have better resistance to molecular chain shearing and flow better in extremely low temperatures. The former is important in motorcycles with the gearbox being lubricated by engine oil as gear pressures like to shear long chain oil molecules. The latter has little importance as people don't ride in -40 degree temps. The oil change interval can be extended with synthetic oil as shear is a big reason for the need to change oil.

If all that is too much information, just make sure your oil has a JASO rating. That means it passed tests for motorcycle wet clutch and gearbox use. Other automotive oils will work fine too but their manufacturers want you to buy their more expensive motorcycle labeled oils and also didn't want to spend the money to have their car oils tested by JASO.

The only differences between most manufacturer's motorcycle oil and its car oil of the same weight are the label, JASO testing and price. The same oil goes in each container.

[mr_diver]

The key thing to remember...

Don't put car oil marked as 'Energy Conserving' in your bike. That WILL naff the clutch.
Castrol Edge (new version of Magnatec) is one of the energy conserving types.

Most dealers will only supply 10w40 Semi Synth oil for service work unless the bike specifies Fully Synth and a difference grade.

[mallywoods]

Thank you, that was an exceptional explanation and happy to carry on doing my own oil changes using castrol synthetic motorcycle oil.

[bosnjo]

I've always used what my dealer would put in it. I do all of my own maintenance but I have no way to safely dispose old oil. So I prefer to do it at my dealer instead of practicing environmental crime.
My dealer uses semi-synthetic oils. I was never very Harpy with the way bike shifts and complained few times. Some time ago, he told me he changed supplier and now uses very good semi-synthetic oil. After the last change, bike started to shift like a dream. But, after 3000 km's it started to shift like a crap, again.
It's now almost on oil/filter change schedule (I do it every 6000km's and not 12000 as per Suzuki specs), so I went and ordered Motul 7100, fully synthetic, as my dealer doesn't have any in stock. I want to test that one and see how would shifting behave.
One thing I learned for sure. The smoothness of the shifting on my bike depends a lot on the engine oil used.

[Flanners]

or 4L 10w/40 Shell Ultra fully synth for £24 on the bay!

[mallywoods]

Thank you all that was very informative I will use fully synthetic but NOT energy conserving. Thanks again for your comments all very help full.