viscosity
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Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: San Antonio Texas
viscosity
my 79 was rebuilt before i got it. has aluminum heads. sticker on oil fill caps say "use only 5W 30". i live in south Texas. i'm not sure i've ever even seen 5W 30 down here. is this really needed? why?
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
Multigrade oils have one advantage over single-weight oils. The lower cold-temperature viscosity means that oil can circulate more quickly during the critical period after engine start 
Many modern vehicles use 5w30, like my F150. And the newest F150's specify 5w20!
Many modern vehicles use 5w30, like my F150. And the newest F150's specify 5w20!
Burning Brakes
Joined: Apr 2000
Posts: 1,012
Likes: 0
From: Minnesota
Originally Posted by page62
Multigrade oils have one advantage over single-weight oils. The lower cold-temperature viscosity means that oil can circulate more quickly during the critical period after engine start
Many modern vehicles use 5w30, like my F150. And the newest F150's specify 5w20!
Many modern vehicles use 5w30, like my F150. And the newest F150's specify 5w20!
Most engine damage is done within the first 30 to 40 seconds of engine start up. Like said above the lighter weight oil flows easier and gets to the much needed top end. If the car sits for longer periods of time in betwen runs its even more critical.
SEMPER FI--1970 Dave
