Just wondering if you guys recomend 5w 30  in the 620 engine series?

What is your favorite? 

I know, This could get interesting :shock:

asking about the viscosity to use on these L series motors could get you a wide variety of answeres....
I use Union 76 20w/50 and have used it in most every motor I have driven over the last 30 years...
I say most as I tried Mobil1 Synthetic in a 318...good stuff but pricey when it first came out...
Datsun recommended 10w/30 or 20w/40 or even 20w/50 for the 521:
http://olddatsunpickuplovers.com/attachment.php?id=203

notice how 76 isn't mentioned in the manufactures listing there?

good luck in deciding....

Oh, and 5w/30 is recommended for 60 degrees down to -20 degrees farenheight
check out page 10 here for the 78 recommendations:
http://www.the620.com/data/Datsun_Pick- ... l_1978.pdf

[user=475]lil_hustler_620[/user] wrote: [quote]Just wondering if you guys recomend 5w 30  in the 620 engine series?

What is your favorite? 

I know, This could get interesting :shock:
[/quote]
Yes, I think that's a good choice for your engine.

Here's why:

viscosity (thickness) decreases as temperature increases

Engines need a thin oil at startup, so that it can get to the engine components quickly, but it needs a thicker oil when the engine is hot because a thin oil becomes too thin.  This is why engine oils are supplied as dual-grade weights.

When you see 5W-30 on a quart of oil, it means that it acts like 5 weight oil when it is cold (the "W" means winter), but acts like 30 weight oil when hot.  This is not to say that it is actually thicker when it is hot.  Hot 30 weight oil is thinner than cold 5 weight oil.  Even so, it still helps provide the benefits of both types of oil depending on its temperature. This is why single-grade oils are very bad.  Straight 30 weight oil is way too thick when cold to properly lubricate the engine.  5W-30 and 10W-30 breakdown at about the same point, so I use the 5W-30 in the winter. During the summer, and when I have a long road trip to say, Las Vegas, I bump up to a thicker 20-40 or even 50 weight.

When you have an engine that leaks, thicker oils leak slower...lol. Stop-leak additives are just oil with added sludge to make 'em thicker.

Don't use any additives like those "seen on TV", either. They're either chlorine based or have chunks of Teflon in it. I wouldn't want either in my engine.

Synthetics are expensive but, great if you need them. I don't use 'em on any engine that's not hopped-up or makes excessive heat, (re: hot cams, turbos, ect.). Plus, the last time I used a synthetic in a leaky Datsun mill, I noticed it leaked worse. Must be all that scientific molecular uniformity. Dinosaur juice is fine for me.

Just remember to change your oil frequently! I service my cars every 1500 miles. 

~phiz 

 

 

[user=4]71-521[/user] wrote: [quote]
notice how 76 isn't mentioned in the manufactures listing there?

[/quote]
I don't know when that thing was published but, now that the "76" lubricants brand is Chevron owned, I guess you could say it's kinda listed....lol.