Originally Posted by GaryPoe
I have nothing against using conventional, ive used it in my lawn mowers and.... well thats about it. I have used PP once in my 98 expedition "trade in" and was plain jane yellow bottle dino. I still have a bottle and as matter of fact its what ive been using for lawnmower oil
The main factor about me using synthetics are the pour points. Here in Iowa when temperatures drop to -20f with wind chills in the -30f to -40f, I like the reassuring feeling that im not going to shell my engine when i start it up. That and from every single article ive ever read online and in automotive magazines have "proven" that conventional motor oils cant hold a candle to anything synthetics can do. Sure you cant beleive anything on the internet. Or car and driver magazine. Or sr. tech billy bob at the dealership. If only there was a majic oil that does everything better than the leading competition.
Generally conventional oil (especially thinner grades) are good down to -20F. The windchill factor has no effect; so don't use that as justification.
What you've read about syns is often true; syns do have some advantages when it gets cold out. But that typically isn't until temps lower than -20F. And honestly, your routine temps there in Council Bluffs are not really any colder than here in IN. Your average low in CB is +14F; ours is +18F. Sure, you do get below zero upon occasion, but don't exaggerate the nature of the "cold". You rarely get down to -20F. Your record low was -32F. Ours here around my area is -35F. But those are RARE temps for you and me. You routinely will see 0F; rarely would you see -20F. Data don't lie.
https://weather.com/weather/monthly/l/USIA0192:1:US
I use conventional 5w-20 in my 4.6L mod motors; I get excellent wear rates. I see the same darn temps as you do, within a few degrees on average. I've run both syns and dino oils in many UOA tests and the wear rates were not affected by the use of syns, even out to 10k miles (my normal OFCI).
The reality is that your warm up cycles are causing the elevated Fe wear. That won't kill your engine, but using syns isn't going to save it either.