So I have always been a Chevrolet guy having had a 62 Impala and a 70 Nova. I just picked up a 66 LeSabre base model with the Wildcat 350 variant of the 340ci V8. Now in my Chevys I usually ran a 40 or 50 weight engine oil in the summer. I imaging this Buick mill is very mild as far as the cam goes. I was thinking of running either 10w30 or 10w40 Mobil 1 High Mileage oil as it has some extra zinc (SL rated) versus the standard non high mileage stuff(SN rated). Any thoughts? pardon if this has been discussed into the ground already...newbie here. My use of the search engine did not turn up much on proper viscosity for these old machines.
With ANY engine, you run the thinnest oil that gives you satisfactory oil pressure. For the SBB, that is 10 psi/1000 RPM. Running thicker oil only wastes power and further heats up the oil. Every Buick should have at minimum a good oil pressure gauge. I like the Joe Gibbs or Brad Penn oils with the proper zinc/ detergent additive package. http://www.v8buick.com/showthread.php?222499-New-Oil-tech&highlight=
What Larry said. :TU: I like to use 5w30 Mobil 1 High Mileage Full Synthetic for stock engines with good oil pump clearances to support the thinner oil and Cam Saver lifters (which bleed down 1-2 PSI at idle). Stock Buick engines/camshafts are engineered to last a very long time and are very gentle on the valvetrain. You will be fine using this off the shelf oil available at any Wally World or similar store. It is available in 10w30 and 10w40 if you need that thick of an oil. Factory oil was 10w30 I believe. Nominal phosphorus ppm is 1,000 and Nominal zinc ppm is 1,100 ppm for this oil, which is plenty good for a stock valvetrain. Higher levels are not needed and can in fact actually be harmful over long periods of time. As long as you have enough, that is enough. :TU: Link for the zddp levels in various Mobil 1 oils: https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.ashx One of the nice things about keeping your OEM engine all OEM is its longevity. Enjoy! Gary
Thank you guys. This is going to stay stock. Being unfamiliar with any Buick engine outside the Grand National V6, I just wanted to know if these old mills needed anything special I was unaware of.
