Thank you for the great info! Yes it is true, we are not hammering our engines, so why all the cost if it won't be of any benefit? Sorry for my misquote, stating a 25W50, yes I will be using a 20W50
That's the way I look at it, anyway. I understand the benefits of Group IV/V race lubes in highly-strung race engines or modern street engines with extremely long (>15K mile) oil change intervals. But I really don't buy into the "benefits" of synthetic oil on low-revving V8s from the dinosaur era
it is readily available in SA from the following manufacturers, Shell, Total, Caltex and Castrol.
I'm sure any of them would be fine. Porsche guys seem to bash Castrol GTX lately, but BMW guys still swear by it. Some people trash Shell Rotella, but others think it's fantastic. There seems to be a lot of fanaticism when it comes to oil. I honestly think as long as you change the oil every 3K miles, you could probably use olive oil and it wouldn't matter too much
It is really interesting to note that Mobil 1 is not a "true" synthetic. It is extremely expensive in South Africa!! Is Amsoil a "true" synthetic? Do you have any knowledge on Total 5W40 Racing Synthetic? Any good? It is available in our town.
Last I checked, Mobil 1 used Group III base stocks...just like Castrol Syntec, Royal Purple, Valvoline Synpower, and most other oils that are marketed as "fully synthetic."
Amsoil has always used Group IV base stocks. It's probably the most widely available true full synthetic on the market. Red Line, Motul 300V, Elf/Total, and Torco SR-5 (but not SR-1) are other relatively common choices for Group IV/V full synthetics.
The way I see it, if I'm going to spend the money on a "synthetic" motor oil, I want to make damned sure it uses PAO or ester as a base stock. To cut through the marketing hype, just see if the manufacturer mentions Group IV or V in their literature. If not, you can bet they're using a hydrocracked petroleum base stock. How much you're willing to pay for that is up to you.