Fully synthetic oil?

[doofus4000]

From doing a bit of reading on the forum, I'm guessing bikes just dont use fully synthetic oil like most modern cars require? Do most people use semi synthetic over regular synthetic then? looking at changing the oil on my 05 bike and not sure which oil to buy. I have some good 10w40 car oil, would this do the job just as well?

[jambo]

One of the sticky posts at the top of this section may be of interest to you:
http://forums.sv650.org/showthread.php?t=125457

[doofus4000]

Yea that's more or less what I'm asking you guys..does no-one use fully synthetic for bike engines for any reason, is it bad for them for any reason? In terms of cars its definitly better oil, I would of thought the same for bikes. But people seem to use semi synthetic.

[NTECUK]

Just save your money and use Halfords motorcycle specific 10W40 oil

[TheRamJam]

I use Silkolene Comp 4

Never had any issues with it, and its not too expensive neither.

[timwilky]

There are significant differences between oils designed for bikes and those for cars. remember in bikes the oils must also work within the gearbox and clutch systems.

Just like with cars, you can find mineral, semi synth and full syth oils for bikes.

some bikes are designed to use a full synth bike oil. the SV is not such a bike. therefore use the oil that the SV is designed to use. A semi synth. The Halfrauds/ Hein Gerricke is good enough. If you must use a named brand use Castrol Power 1 (GPS)

[MJC-DEV]

I currently use Halfords Fully Synthetic Bike oil as it''s not a lot more than semi and is longer lasting. I have always used fully synthetic car oil in my bikes to no ill effect.

[Bibio]

do not use fully synth car oil in your bike as your bike has a wet clutch and the car oil will ruin the clutch plates due to the modifiers in the oil. only use bike specific oil in your bike as its designed to be used with wet clutches.

if you have a dry clutch bike then use what the hell you like :-)

[Sid Squid]

I said this:
There's no doubt that even if you do decide to use Spry Crispy & Dry, it will undoubtedly give best service if it's changed with appropriate regularity, it is without question that it is a horrible false economy to run oil longer than you should.

Spanner Man: I agree, generally. There is no doubt in my mind that fully synth oil is quality stuff, however - and this is the crux of the matter - it's dear, some bike specific brands are very dear, and whilst it may do a great job I do sometimes wonder if it is an un-necessary extravagance.

Using the example Spanner Man quoted, and some rough figures:

200,000 miles at 3000 mile oil changes - common figure = 70ish oil changes, (bit of rounding off to make the numbers easy). Let's say you were to use a fully synth you would typically spend about £8- 10 more per 4* litres than if you were to use semi synth which could work out at more than £500 extra spent. Hold that thought.

Now I'm well aware that you might say: A-ha! but that motor would have been scrap at, say, 150,000 miles if you weren't using fullly synth oil. Well, possibly, but exactly how many modern bikes get to anything like even the smaller figure, or even 100,000 miles?
Very few, very very few, as the bike will more than likely be scrapped for reasons other than the motor being worn past the point of use well before that time. Anyway, if you were to change the oil when you should using cheap n' cheerful semi synth I'm certain you'll get 100,000 from any sort of modern engine.

Hold on I'm not done yet, but it won't be long now.

Ask yourself: How long am I going to keep this bike?

1 year, 2 perhaps, maybe 5? How many miles am I going to do in that time? Let's be generous and say 50,000 miles, (and yes as far as modern bikes and riders go that's plenty generous), well, you could happily use any cheap oil and get well past 50,000 miles, any extra money you spend on the machine including the extra spent on high quality oil that you may put in it, might give you a warm fuzzy feeling, but will make no practical difference to your bike in the time that you own it, and probably no difference to the next two owners either.

Yes, I do understand perfectly the desire to do the very bestest for your dear darling motorbicycle, but stop emoting and start thinking, that's money that is, your money.

* Clearly this depends in part on the oil capacity of your machine, and futher true I've not fussed over any exactities, however the principle is good and the simple fact is so few of us as to not be worthy of mention run a motorcycle so far through it's life, that the necessities of lubrication will ever be a factor.

PS If you're planning to do 200,000 miles on your bike, buy the fully synth, it may well be dearer than a replacement motor, but it won't be off the road to have it fitted, this is fully synth's only practical redeeming factor, maybe. :lol:

Discuss.

[timwilky]

I currently use Halfords Fully Synthetic Bike oil as it''s not a lot more than semi and is longer lasting. I have always used fully synthetic car oil in my bikes to no ill effect.

Despite no ill effects using car oils, you have now decided to use a bike oil. OK, I can accept that. After all any oil is better than no oil.


There are people on the forum who are experts in oil design. I am not one. I am by profession/training an automotive engineer who spent a number of years on engine design. We didn't design the oil for our engines. We advised the lubricant manufacturers of the day the operating parameters and they designed the oils.

Just because car oils didn't break your engine, doesn't mean they are best suited compared to oils designed for the operating conditions of a slow reving v twin motorcycle.

[rictus01]

the one thing I'd add to what has been already said, no matter what oil used, don't let quality dictate the frequency of change, apart from lubrication the oil also scavenges any contaminants (hence turning black), and for this alone should be regularly changed.

Cheers Mark.

[MJC-DEV]

Seriously guys, I used cheaper brands of Fully Synthetic car oil in my GSX750F's for 16 years with no clutch slip. Some people have had clutch slip with the likes of top Castrol with friction modifiers etc but I always used the cheapest (correct spec: API-SF 10W40) stuff with no problems. Sure, it safer with bike oil but a bit extreme to say 'do not use' outright.

I now use Halfords full syn bike oil simply because the price and availability is very good at the moment and always stick to the manufacturers change interval.

Oil designed for slow reving v-twins - really? Which ones would they be then and how would it be different!

[timwilky]

I was being a bit tongue in cheek with the reference to designed for slow reving V twins. However when you make the comparison with a full on il4 track screamer. There is a big difference in the required oil specs between the two.

Oil use on a bike is far different to how modern oils are designed for cars. I don't think since the demise of cars such as the Austin Maxi where the gearbox formed the engine sump have an engine and gearbox shared the same lubrication system. Gear oils have to go through a continual shearing which causing foaming and breakdown of the oils. Motorcycle oils are developed with this dual purpose. Mention should also be made of friction modifiers that are found in some car oils. These may have adverse effects on wet clutch systems.

As I have said. Any oil is better than none. But the best is one designed for the specific purpose.

If you were lucky enough to own a desmosedici. (Best example of performance erotica available to Joe Public) would you put chip fat in it?

[MJC-DEV]

Actually I agree with all of the above and its one of my reasons for full Synthetic (personal fad it may be) in that the long chain molecules in the Full Syn base resist being chopped up by the gear box better the mineral base oils so that they (FS) maintain their rated viscosity longer (No I can't prove it :) ).

Moot, this advantage is to a non turbo engine with 3k5 mile change interval and the fact that Suzuki only spec a pretty lowly SF grade.

The devil in the car vs bike oil debate is the friction modifiers bad effect on the clutch. Full synth or even semi-synth is not actually needed for the SV with an API-SF spec requirement I believe?

[MJC-DEV]

Update: From API-SJ it looks like car and bike oils have diverged [probably due to the aforementioned friction modifiers] so while I could have used the same car oil in the past, it is less clear if they will work now. Current car spec is API-SN which is NOT tested/rated for wet clutches.

Thanks to Google!

So looks like everyone is correct:
Don't use modern car oils, except at risk
Full, semi or mineral personal preference.

[Bibio]

here is an interesting article by Millers oils: PDF

http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&sqi=2&ved=0CHwQFjAA&url=http%3A%2F%2Fwww.millersoils.co.uk%2Fpdf%2Faut omotive%2FRace_Engine_Oils.pdf&ei=tKSzT6rPO-O90QXD8NiLCQ&usg=AFQjCNGET-Z0ZvBqgTCv7RcJYMPTIrcdQg

[doofus4000]

Ok thanks for the replies all.

I never was really thinking about the car oil but wanted to know why it wouldn't be suitable and thats been said above, thanks.

So a 10w40 of either semi or fully synthetic bike oil is only to be used. Thank you all.

[embee]

Just another 2p

Aside from the wet clutch issue (the relevant test spec for that is JASO-MA, it'll be on the label somewhere if it's approved), there is the suitability for the transmission side of things, as noted by others above. Specific to this is the anti-wear/scuff additives, typically ZDDP or at least phosphorus carrying compounds, used to protect the high pressure contact at gear teeth.
Because metallic based compounds cause catalysts in the exhaust to deteriorate (the metals attach to the platinum etc particles in the cat and effectively de-activate them) the levels of these additives have been reduced pretty dramatically in car oils over the years. Bike oils will have typically twice the levels of these additives to protect the gears and transmission over the longer term.

Use a bike oil if possible.

[yorkie_chris]

I was being a bit tongue in cheek with the reference to designed for slow reving V twins. However when you make the comparison with a full on il4 track screamer. There is a big difference in the required oil specs between the two.

Personally I don't think there is.
Peak piston speeds, bearing loads, etc.
Massively lower crankcase tidal volume and pressure changes.

More in it than just the number on the red bit next to where it says rpms innit.

Bear in mind suzuki say there is absolutely no difference in oil spec between the two as well ;)



There's more BS about oil than owt else. I've used fully synth car oil in the bike, and semi, and had no problem. I've currently got fully wet-clutch-approved motorcycle specific oil in my XJ900... and the clutch is slipping!!
99% of people won't go anywhere near the mileage to notice. My SV's done about 100k, around 20k of that, early on, it was fed on car oil because I was skint. It's still running fine and the transmission is as slick as any SV I've ever ridden...


When people come to me I supply them with bike specific good quality oil... cos I'm not being responsible for a f*** up...



Good luck finding "mineral" oil that meets the correct viscosity anyway.