Originally Posted By: Keith_Stone
If comparing oils for air cooled OPE's over wide temperature use and striving for the lowest wear would oils like Amsoil ACD, Rotella T5 (I think you meant T6) , Mobil 1(EP), work equally in most applications? Is there really any point in synthetics for yearly oci's with/without filtration?
The answer is an unqualified YES! Sure, conventional 30W will work just fine in many applications. But, I've experienced rapid engine failure due to heat related issues. As have many Florida hurricane victims. Properly chosen synthetics perform very well at 250 degree oil temps and at -10F start up temps. Something a conventional oil cannot do.
I use M1, 15W-50 in my Subaru 11HP generator. It now has well over 1000 hours use on it, and still runs perfectly. Quite unlike my neighbors units.
I use M1, 5W-40 TDT in my other OPE, with equally good results.
Penzoil 5W-30 failed in 2 Honda powered waterpumps (used to de-water my yard to avoid wetlands mitigation fees) They ran 24/7 under absurdly hot conditions, with oil changes every 2 days. The result was rapid engine failure. Would straight 30 have been better? You bet. But, M1, 15W-50 really is the proper answer in that case. And will result in significantly longer engine life under severe conditions.