GMC 4.3 dino oil for 5K changes

[Gene K]

Local large pest control company (in house maintenance department) buys 5W30 in bulk under contract from the cheapest bidder. They do 5,000 mile changes.

Last time I asked they had several 4.3L over 400,000 miles.

 

[JDD]

Originally Posted By: 45ACP

Hmmm. 5W-30 or 5W-40, heck even 0W for this engine with the new oil and it will like it.

(It IS A small block short two cylinders.)


The only issue with a 0W XX oil is if it leaks. And quite frankly, I haven't seen one of either the 4.3 or 5.7 older than say 8-9 years that doesn't have a fairly decent oil leak issue. Usually the rear main seal. 0W oil may not be the best if there is a leak there. One of my very few complaints about GM is that if it holds fluid, at some point it will leak. Been that way forever in my experience.