5w or 10w/30? Options

[mwpayne]

Just bought a '95 celica ST. Needs an oil change, is 5w/30 ok? Reason is I also have a 2002 camry that uses that, it would be nice to stock one oil for both cars..

[Supersprynt]

Your right - kinda. The W isnt just for "winter" its just plainly the viscosity of the oil when its cold. The most wear in an engine come from start up, this is generally when theres no oil pressure and oil hasnt reached every where yet. so a thick oil will take longer to get everywhere while a thinner oil will reach vital parts quicker. Thats the first number in say 10w-30. 10 is the viscosity of the oil when its cold, 30 is when the cars warm. So 5w-30 is the same as 10w-30 when your engine is warmed up.

So theres pros and cons to using a thicker weight oil. 5w will get to your engine parts quicker while the 10w will take longer. And the 10w will add some cushion but take longer to get to the parts. And in the end when yoru cars warm they're both the same.

You'll be fine with a 10w-30. Semi or full synthetic is what i'd recommend for the age of your car.

[southwest2118]

The most wear in an engine come from start up, this is generally when theres no oil pressure and oil hasnt reached every where yet.

I heard this before . i was thinking ....

right after a rebuild your supposed to disable spark and just crank the car for a couple of seconds....

soo if you disable the spark from a switch in the car.. and crank for a couple of seconds then engage the "spark switch" then turn on the car.....will that help in the long run??

[Yellow94GT]

The most wear in an engine come from start up, this is generally when theres no oil pressure and oil hasnt reached every where yet.

I heard this before . i was thinking ....

right after a rebuild your supposed to disable spark and just crank the car for a couple of seconds....

soo if you disable the spark from a switch in the car.. and crank for a couple of seconds then engage the "spark switch" then turn on the car.....will that help in the long run??

I though cranking a fresh rebuild was rough because the oil pressure was extremly low and the internal friction was very high. Since the oil pump is virtually empty and most friction points don't have the oil fed through the oil galley to the bearings and rings.

Opps I hit the wrong key and I think I sent out an incomplete post.
I though cranking a fresh rebuild was rough because the oil pressure was extremely low and the internal friction was very high. Since the oil pump is virtually empty therfore most friction points don't have the oil fed through the oil galley to the bearings, rings and cylinder wall and pistions.
"Back in the old V-8 days "I used to leave the distributor off on my rebuilds and prelube the engine by using a a long slotted screwdriver attached to a drill to turn the oil pump with for a couple minutes. This would send oil through the empty oil passages to the vital friction points, bearing, rings, pistion, cylinderwalls, etc. You could watch the oil pressure gauge pump up to opertating pressure. All the air was forced out of the lubricating system and then the distributor was put in and the engine could be started without all the harmful dry post rebuild scuffing.
I understand that all the good oil filters have check ball/valves to keep the oil volume high for restarts.
The oil filter on the 5S-FE engine faces downward and doesn't allow for me to fill the filter full of oil prior to installing it.
I don't know if disabling the spark while cranking a "not freshly rebuilt" engine will give similar benefits to an engine that has not been just rebuilt, since the lubricating system already has purged the air and of oil in the vital places.

Yellow94GT

This post has been edited by Yellow94GT: Mar 20, 2006 - 9:47 PM