OILS AINT OILS

[lombardi]

Can someone shine a light on the contentious subject of oils- ie mineral versus synth + which grade + intervals in changing oils, seems everyone has different opinions on this subject, whats the best brands,is there a difference ! OR THEYRE MUCH THE SAME- one opinion to highlight is if u have an old car ie alfa 105-mineral is better,because this was the oil used at time of manufacture,even if engine is rebuilt--as well what about diff and gearbox oils-is synth better and worth the extra investment.ciao

[dehne]

hi i have found that bp course plus is great for the older alfas ie 2ltr 1.8 ect but when it came to later mdls 2.5v6 and 3ltr thatthe castrol magnatec is great but with most big oil retailers ie shell, mobil, ect do have quality oils which are all reasonably priced then you can spend a little more and go for the penrites fuchs castrol which are really good i think what it comes down to is what you like and also what urcarlikes as for some reason certaincars dont like some oils
i hope i have confused you a little more

[Jack]

Oils.
I purchased some very good oil from a chap called Leon Frank.
If you care about what oil you use he's worth a call.
His business hours number is 0419 365730.
A good chat and VERY knowledgeable.
Il prezzo, è di destra.
Cheers.

[Doug Gould]

I changed my GTV6 to Castrol R 5W30 and its using less oilo than with heavier oils. Go figure!

Doug

[Allegerita]

Heres an extract from http://www.carbibles.com/engineoil_bible.html

'Grade counts too!The API/ACEA ratings only refer to an oil's quality. For grade, you need to look at the SAE (Society of Automotive Engineers) ratings. These describe the oil's function and viscosity standard. Viscosity means the substance and clinging properties of the lubricant. When cold, oil can become like treacle so it is important that any lube is kept as thin as possible. It's cold performance is denoted by the letter 'W', meaning 'winter'. At the other end of the scale, a scorching hot oil can be as thin as water and about as useful too. So it needs to be as thick as possible when warm. Thin when cold but thick when warm? That's where MultiGrade oil comes in. For ages, good old 20W/50 was the oil to have. But as engines progressed and tolerances decreased, a lighter, thinner oil was required, especially when cold. Thus 15W/50, 15W/40 and even 15W/30 oils are now commonplace. Synthetics can go down as far as 5W which seemed unbeatable until Castrol came up with SLX - a 0W30 formulation! 'Free flowing' just doesn't describe it! It's predominantly a workshop oil retailing at around £10 ($15) a litre, but recommended for use in places like Canada in the winter. The latest offering to this 0W30 engineering miracle comes from AMSOIL.'

Always wondered what the "W" meant....

[Allegerita]

"Synthetic" oil - which is predominantly derived from mineral oil -  is more refined and superior to standard motor oil.  It can maintain its characteristics both at below freezing and at higher temperatures (around 450 F). It is also more "slippery", this reduces internal friction, makes your engine run cooler and improves fuel economy. Synthetic oil has a longer life than regular oil as its structure doesn't break down as quickly.

Various articles state that when purchasing multi-grade oil, select the narrowest viscosity range for the temperature range you are going to operate your vehicle in. Oils with a wide  range use polymers to help the oil operate at the same viscosity over the temperature range, these polymers however, degrade and can void the warranty of your vehicle.

Theres heaps of articles on the net which explains synth. vs mineral oil.