Hi
Can some one advise me on what engine oil to use...???
I've been on many forums and and read mixed reports....
10/40 semi synthetic or traditional morris 30 or even a 15/50 .????
Thanks
All opinions welcome
Engine oil
Oil choice
First point:- a rule actually - don't use synthetic unless it's a newly rebuilt engine with a full-flow filter, and you must still run-in with a normal oil.
The reasons are that without the oil filter you must change it every 3000 miles, which is stupidly expensive, and if you put it in an old engine, it is very likely to clean out the muck from all the corners and clog the oil passages.
There is also a higher probabliity of oil leaks with synthetic.
Second point:- aircooled engines rely heavily on the oil cooler, and if your oil stays thicker, it will not flow as easily through this, so your engine will run hotter.
For that reason, you will probably find that in the UK the HD30 oil that Morris sells will do the best job.
Some people with worn bearings will put in a thicker - even 20-50 maybe, but it will run hotter, and is no adbvantage really. In winter, it may sludge up too.
If you know what it's been run on, that's a good starting point. If you want to change, do it gradually, and be aware of the detergency factor which may clean out gunge, straight into your oilways.
Others will probably disagree with me on oil grades. Maybe they're right to do so! Plenty of people have run them on all sorts of oils without apparent problems. We don't have the extreme conditions in the UK to make the final difference really.
Another note:- the idle oil pressure is often less than 10psi even on a good engine. The oil pressure light comes on at 5 - 8 psi, and can vary from switch to switch. If the oil is very hot, or the engine worn or both, you may get the light flickering at idle. VW say it's fine as long as it goes out when you press the accelerator.
The pressure in the bearing is generated dynamically as the surfaces rotate. Very worn bearings lose the oil before it can generate this pressure, which is when the engine starts running a lot hotter and the wear accelerates.
The reasons are that without the oil filter you must change it every 3000 miles, which is stupidly expensive, and if you put it in an old engine, it is very likely to clean out the muck from all the corners and clog the oil passages.
There is also a higher probabliity of oil leaks with synthetic.
Second point:- aircooled engines rely heavily on the oil cooler, and if your oil stays thicker, it will not flow as easily through this, so your engine will run hotter.
For that reason, you will probably find that in the UK the HD30 oil that Morris sells will do the best job.
Some people with worn bearings will put in a thicker - even 20-50 maybe, but it will run hotter, and is no adbvantage really. In winter, it may sludge up too.
If you know what it's been run on, that's a good starting point. If you want to change, do it gradually, and be aware of the detergency factor which may clean out gunge, straight into your oilways.
Others will probably disagree with me on oil grades. Maybe they're right to do so! Plenty of people have run them on all sorts of oils without apparent problems. We don't have the extreme conditions in the UK to make the final difference really.
Another note:- the idle oil pressure is often less than 10psi even on a good engine. The oil pressure light comes on at 5 - 8 psi, and can vary from switch to switch. If the oil is very hot, or the engine worn or both, you may get the light flickering at idle. VW say it's fine as long as it goes out when you press the accelerator.
The pressure in the bearing is generated dynamically as the surfaces rotate. Very worn bearings lose the oil before it can generate this pressure, which is when the engine starts running a lot hotter and the wear accelerates.