Engine oil....help needed on choices

Depends on what ya been burning up til now . I switched from a paraffin based eastern crude to Castrol in a truck (86 GMC 305 cid) and it started burning oil because the oil cut the paraffin based crud/deposits from the valve seals . Replaced them while I had it down for a timing set R&R and all is now well .

As long as your engine is dry on the outside, I wouldn't change anything.

"stinking hot" Arizona, I'd be using Synthetic for sure. (I do here in Ontario too) No issues with switching - the first change of synthetic you might want to do a bit sooner than if it was already on Synth - the stuff will purge a bit of crap from the engine if it has been neglected at all. You are putting the miles on it pretty slowly - a good synth changed once a year or so should do fine. For your use, I'd look at a synthetic "all fleet" diesel rated oil like shell Rotella T6 5w40, or even a T5 synthetic blend if you want to "cheap out" a bit. Won't give the protection of the T6, but better than what you are using now. The all-fleet oil will have more EP additives than your standard gasoline engine oils (More Zinc)

On 07/02/2017 5:19 PM, Terry Coombs wrote: ...

+1 on the paraffin-based. Had old Chevy 350 plug up the return holes on 7 and 8 cylinders from the crap one of them left in the upper valve covers -- was one of the early pollution-control systems and consequently ran hotter than earlier of same vintage; was the death knell for it. Rebuilt with new mains and all and did the switch to Castrol and it did another 250K before donating it to one of the charitable contributions outfits...

My advice "as a mechanic" is to use synthetic where either extreme high or extreme low temperatures are encountered. Been using it exclusively on my own vehicles for about 8 years here in central Ontario on my Fords and my last Mopar. I don't put on a lot of miles and I change twice a yeat (the 21 year old truch has about 350000km on it, the 16 year old car 108,000)

Mobil 0w10 is excelent gun oil I mostly use valvoline full synthetic of the proper weight in my vehicles