I am sure this has been discussed here, as it was in the last GSXtra, but the Alfa board has had some interesting discussions, many of the respondants claiming no wear in their high revving engines on non-zinc oil. Anyway, Castrol is selling Syntec 20w50 with high zinc content and adviertising it as being for older vehicles(see the link). Is 20w-50 a good weight for our engines? Thanks, Dan http://www.castrol.com/castrol/genericarticle.do?categoryId=82915470&contentId=7032644
In my opinion it is not! Use the ZDDP additive and use over the counter 10W30 or straight 20 or 30. I live in Michigan where it gets cold so anything 50 weight is to viscous. Mike D.
20W50 is okay for a Chevy motor, but the Buick motors tend to like thinner oil (10W30 or so). If your engine was rebuilt by a Chevy shop, and has wide clearances, 20W50 will keep the oil pressure up. Good to know that at least one oil company is addressing the zinc issue, even if in the wrong viscosity for us. I suspect most Alphas have roller cams, but I'm not positive. -BC
15-40 Rotella works the best for me. I add MOA (BG products). I like the results. Got rid of a nasty lifter tick I was having too.:TU:
A good rule of thumb is to run the thinnest oil that gives you 11-12 psi per 1000 rpm. If you're making serious power then a thicker range might be more appropriate, other wise it's a band-aid for something else that's not right. Just my $0.02. There are as many opinions on oil as there are brands & viscosities. Devon
I used to use 20-50 in my 455 and I'll never do it again as I had to rebuild it:dollar: a couple years after I started using it. I've used nothing but straight 30w or 10-30 since then and after 9 years it still runs fine with good oil pressure.:beer
Mike Phillips suggested I use the 20W - 50 in my motor. I use the Brad Penn - Penn 1 green racing oil and so far so good. I only have a few thousand miles on it though. I live in South FL where it's always hot ...... if that makes a difference.
