Oil Specifications - Please Clarify

[nvmysv8]

Hi all,

I must start this threat by admitting I have very little knowledge on oil.
No doubt with all the knowledge members have on this forum, someone can set my straight.

I am a little confused about oil grades, i.e 15W/40, 5W/50 etc etc etc.
I went to get some oil for the Barina today and asked for MOBIL SUPER XHP 15W/40 as this was the oil recommended to use when I rang the mobil lube line.

The guy at REPCO didnt have that oil in stock and told me to run it on 20W/40as this is what the manufacturer recommends. He was going off a database in his computer. Thinking he just wanted a sale, I decided to go elsewhere to find the oil.

So I went up to SUPERCHEAP auto's to see if they had the SUPER XHP 15W/40. The guy at SUPERCHEAP told me to use MOBIL 1 5W/50. He said it would be better for the engine when I initially start it and that it will give greater protection (being a 50 grade oil) when the car is under load or running in hotter conditions.

I was now totally confused and decided to head home and post this thread on the forum.

Can someone explain to me the oil specifications. What is the difference between all the oils above and most importantly, what should I put in the
92 1.3lt Barina?????

Thanks
Jason

[Blown 454 AWD]

I would love to rewrite all this info again (NOT)

You need to understand what oil viscosity is all about, to do this do a search on............

Viscosity

cSt

VI

Viscosity Index

SAE

ISO

There will quite a bit of reading however, at the end you should be able to answer your own question.

Remember, it's a little motor, you don't need quite as heavier oil as we run in the V8's however, thicker film strength of oil reduces wear, but then you can go too thick and absorb a little power, there is a trade off.

Then again go too thin (like GM says for the LS1) and you will damage your motor with premature wear.

[IIV8II]

$15 GTX - or any other budget 20/50 oil will be just fine for a Barina. I bought 6L for $10 at Auto One recently