Choice of Oil?

Hi

Seems I need a little over 3 litres of oil if I change the oil+filter, is it worth buying an expensive oil or will Halford's best do just as well £22 for 5 litres 10W40 part synthetic http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_943817_langId_-1_categoryId_165581 ?

Don't want to trash the engine for the sake of spending a tenner more on oil, just trying to choose something suitable.  Any difference between car and motorbike oil, ie is any oil they have that is 10W40 ok?

Cheers

Nige

This question comes up regularly. I asked the very same thing a while back. You may find the thread relevant.

I've used Halfords oil in cars, vans and bikes for years. No problems personally.

Thanks, I did search for oil on the forum but it found nothing - perhaps because "oil" is only 3 letters long?

Ended up getting some "bike" oil, figured I'd feel really stupid if I caused problems saving a tenner on something the schedule says only needs doing once a year (I don't do many miles).

Having said that, I may well change it again in 6 months (filter too), as I don't know what the service history of the bike is like.

Manual says every 4000 miles or every 12 months, mine is unlikely to do 4000 miles a year but that seems a long time between changes?

Nige

nigelb wrote:Manual says every 4000 miles or every 12 months, mine is unlikely to do 4000 miles a year but that seems a long time between changes?

Nige

Doesn't the manual say every 8000 miles or 12 months?
Anyway, if you do it every 4000 or 12 months you'll be fine.

Use 10W40 bike oil (not car). Cheaper oils, changed frequently, is I believe, better for the engine than the higher grade/expensive synthetics left in there for twice as long.

Sorry, you're quite right, and I certainly won't be doing 8000 miles in a year!

Honda's 8000 mile oil-change interval is a bit hopeful : I think (almost) everyone changes it at 4000 miles or so - the oil is pretty buggered after 8000 miles.

The car oil would have probably been fine - the only thing that might go wrong (if you were unlucky) would have been the clutch, which isn't that bad to replace - it certainly won't break the engine.

Personally I prefer slightly cheaper car oil: if it is going to be changed every 4000 miles I really don't see the point in paying top dollar for it.

I've tried doing 8000 miles on the same oil. It worked OK, but I wouldn't risk going any longer than that.

The thing is, oils aren't really 'worn out' - they're 'filled up'. With soot and sludge. Think of your car gearbox or rear differential; how often do you change those oils?

So, observing that my CB engine uses practically no oil and the fact that oil 'discoloration' (soot/sludge!) took ages, I let it go the full interval.

Engines behave differently, so you may wish to make another choice though.

I don't think it is just the visible muck that is the problem.

I believe that as an oil is used (ie. squirted around the place and variously crushed into small spaces like plain bearings and heated up and cooled down) its lubrication properties do fade with usage, even if no muck (soot, petrol, sludge etc) is added.

I wonder about the clutch friction plate material, as it wears away surely it must be floating around the engine until it (hopefully) gets picked up by the filter. 
It really depends on how you are using the bike, if it is 12 months of short journeys where the oil never gets up to temp it could be filled with water and petrol etc, if you give the bike some nice long runs all that stuff can evaporate out.

Hmm, so if I only do shorter runs do I need to replace the oil more frequently than every year?

It's up to you mate, it depends on what kind of weather you ride in, how many miles etc..
But in general I think most engines prefer long runs rather than just nipping down to the shops, you get blow by past the rings when the engines is cold.

+1 what Beresford says.
Here's a simple vid explanation of how oil physically breaks down & why regular oil changes are important. (ok, he refers to Harley but the principle is the same). Fast forward to 5:30


https://www.youtube.com/watch?v=R0lRzW_gLwE#aid=P9NPU6c_LIw

What the vid doesn't mention is that apart from the degradion through shear, the oil gets contaminated by combustion chemicals, which are corrosive to engine components, thus adding to the problem

Well, service mostly done.  Spark plug spanner was the wrong size (doh!) but oil, oil filter and air filters done.

Managed to take the tank off 4 times!  Eventually got all the bits back on in the right place.

Seems to start and run fine still too, ran it for a couple of mins, topped up the oil again, then repeated that a couple of times.

Can't see any leaks so hopefully job done.

Nige

Not just me then, almost nothing left in the 4 litre bottle.

Anyway, revs much more freely low down the revs now :-)

If you get all the old oil out then mine takes 4 litres too, so I think that is just the way it is...