switching engine oil

jeepney driver via CarKB.com did pass the time by typing:

Flushing isn't necissary. You could put a quart of 5w-30 and fill up with

10w-30 synthetic, and 10w-30 dino oil, nothing bad would happen. The only thing that matters is the lowest service life of the oil you put in. That sets your next oil change.

No flushing is necessary. There will be a small amount of the "old" oil in the system but that is not a great concern.

Back-in-the-day, as my kidlettes say, there were concerns about constantly switching brands. I don't recall any mentions in the past decade or two so I imagine it is no longer an issue.

This is a +200K mile engine, right? And you worry about contamination between oils?

JimG

80' CJ-7 258 CID, HEI 4.56 Gears, Lock-Right F&R 35" BFG MT on 15x10 Centerlines D44 Rear, D30 Front. SOA Dana 300 w/4:1 & Currie twin sticks Warn X8000i w/ dual batteries

00' TJ Sport 4.0L, 5sp

4.56 Gears, TrueTrac rear 33" BFG AT on 15x8 Eagle Alloys D35 Rear, D30 Front. 3" Suspension Lift Warn X8000i

It is considered bad form to open multiple threads, just to get one question answered.

Earle

No, there is no need to flush. Some folks have been mixing dino and testtube for years. Nor do you need to flush when changing grades.

Is there a particular reason you'd want to go back to dino?

jeepney driver via CarKB.com proclaimed: