switch to 10w30 oil on 4.3's with high millage..100k+?

hellooo....alll
im wondering.....now that i have almost 140k on my 4.3/w.
should i run 10w30 instead of the 5/30?
iv heard that as the engine wears and miles are high....its good to go to a lil heaver oil....to help compinsate for the wear on the engine..true?

You really don't need to until your truck starts using oil. Most people just switch to a heaver grade to compensate for a wearing out engine.

Plus as the weather gets colder it takes a thicker oil longer to start lubercating properly, making the engine wear faster.

If your worried check out oil on this forum

http://www.automotiveforums.com/vbulletin/showthread.php?threadid=290590&goto=newpost

makes sence........thanks for the info O.B.P. :)

I run 10-40 in the summer and 10-30 in the winter.My engine is quite new.Is this going to destroy it?

Oh I don't really think so Movin2stereo. Although I don't know what the dealer would say if you require waranty work on the motor. They are really the only ones that you have to please.

It's a crate so the dealer isn't involved.Thanks for the heads up,thought I might have done something wrong.

use high milage or high life if your losen oil other wise i would just keep what you usen

don't change your oil weight and for SURE don't use a 10w40 weight in the 4.3L.

All you will do is oil starve the bearings.

You should know better than screwing with the oil weights.

Run 5w30 year around and you will be fine.

I have had a lot of people ask me about motor oil over the years, it really is one of the most vital owner controled variables for engine life. When an oil is 5W-30 it means the cold weight is 5 and hot weight is 30 ('W' stands for winter). So when you change to a 10W-30 all you change is the cold viscosity. What does this mean? If you change to a 10W-30 the oil is thicker at startup, allowing less to leak into the cumbustion chamber (less smoke) but making some parts wait longer for the thicker oil. I continue to use 5W-30 with 138000 miles on my truck.
P.S. Stick to one brand of oil also, each brand is different and changing around can cause unnecessary engine wear.

You are wrong the XX in XXw30 does not stand for a weight. From wat you are saying , the oil thickens as it gets warmer? Take a sample of oil and put it in the freezer and take a sample and warm it up and tell me if the frozen oil is thinner than the warm oil.

No oil is thinner when it is cold. Pure physics.

5w, 10w, 15w is just a flow factor used and measured at -25c.

The lower the number, the lower the pour point and the greater cold weather protection.

It is not tied to any weight measurement whatsoever.