most brendname oils u are paying for the name but i have always chosen MOTUL oil as i havehad all high performance turbo motor and this oil is suited 2 these motors... as for me working in a high performance place for last 3 years in sydney they all used it and so i did 2..
im my ute im runing Motul and in my 1600 i will be runing motul as well..

The gear oil recommendations are:

APL GL-5

1. -30 to 30 Celsius - 80 weight
2. 0 to 40 Celsius - 90 weight
3. 10 to over 40 Celsius - 140 weight

There are also some new multiweights which should work (but which the old service manual doesn't cover).

To refill the diff you will need 0.75 liter.

Why are you all so against Castrol GTX?
My dad used it in his Datsun 510 SSS in the 70's for the car's whole life and put 300 000km on it.No oil consumption during its life.
He said it just used to make a little bit of white foam or sludge on the head inside.
When he needed to adjust valve clearance he would see it there. Alot of people also told me Castrol makes sludge.
I am using now for very long with no complaints. I use it in both my cars.My 1200GX and a 1800cc Volkswagen Mk1.
I like to drive them hard sometimes.
I also know of someone who rallyed with Castrol GTX2. Was happy with his car.
Something else I would like to ask.
What oil must I use in my diff?
I need to change that oil soon.
Must I just use normal gearbox oil?
What viscosity will be the best?

For the 1200 Road race car I use Motul 30wt , for road or break I always used Castrol GTX. Now as far as the Penzoil goes I had heard of it clogging the motor but.... Last May I bought a 71 Volvo 142E from the original owner who used Penzoil , he rebuilt the motor at 190,000 miles and it has 275,000 and is still going stong so I'm skeptical about "brand" rumors. The synthetic oils are worth it for extreme conditions but for a daily driver they maybe over the top. As far as cost goes your talking about $750 extra for 150,000 miles - lets see a rebuild on an A series is about $300 max if you do it yourself.That's 2 1/2 rebuilds for the price of synthetic oil

Tom Grossmann , Las Vegas

In the old days, we used to put the heavyweight oil in tired engines so they wouldn't smoke so much. It did help with that. But I think it makes the engine wear out even faster, since it doesn't lubricate as well.

I knew a guy who used Valvoline 50wt in his 22r Celica for the longest time, thinking it would prolong the life of a tired motor.

Penzoil has a reptuation for "high ash" Pennsylvania crude and clogging up engines ... don't know how true this is though. I reckon that if you change it on schedule you'll have no problems, but if you drive 80,000km without changing it, yeah it will chunk up inside the engine like most other other brands.

Penzoil Synthetic for the racecar (on recommendation from reputable builder)
GP50 in the commodore
The other dats used to use Penrite HPR30

I have a Shell service station nearby & i read the labels on the oil bottles to pick the one i need for whatever i'm driving. They have one for older cars, which suits my 200B. I overhauled the engine thats in it now as a temporary measure untill i reconditioned the original, but despite the bore wear, it drinks almost no oil & runs fine, so temporary is an elastic measure & it's getting stretched. That oil works for me.

In the GX engine, when it was on the road, i used a higher quality, high detergent oil of 10W/30 & changed it & the filter every 5,000 miles [8,000k] For road use in a touring engine, it kept the engine clean, & i never had any problems in the lubrication dept.

In my fleet of Moto Morini motorcycles [i had 3 of the late '76 shipment batch of 10 all at the same time.] I used Penrite HPR30, & changed it every 1,000k. They had no real oil filter to speak of & the gearbox ran in the same oil. I used a magnetic sump plug as well. What a revelation that thing proved to be.

All the major brand names make good oil, you just gotta pick the one best suited to your engine & driving style.
Chris

P.S. If you are running an A series engine, you will find that there are two filters. There was a long one for 1200's & 1000's, which was replaced by a shorter one for 120Y's & later. They are interchangeable & the earlier one has much more filtering medium, so thats the one i always used. I use them on my son's 120Y for that reason also.

I think that Penrite is a small Australian company & i do not know if they export. Type "Penrite" into a search engine & see what pops up.

Can anyone of you please give a description of how the Penrite oil's picture look on the can or bottle?
I live in south africa and we don't get such a oil here.
Maybe we get it under a different name.
We do however get Penzoil and William Penn oil (Is a red heart with Wm Penn written in it).Please excuse the spelling of the oil names if spelled incorrectly.
Thanks for all your replies so far.