CH-4/SL HD oils for rarely driven vehicle?

[Drew99GT]

Would the additive chemistry of the heavy duty oils, 5w-40/15w-40 work better for an engine that routinly sits for a few days at a time, then gets driven a few days, then sits another few days etc.? Do the HD oils handle corosion better? Thanks, and how do they, or better stated, what in the additive chemistry makes them bettter at stopping corosion?

 

[AV8R]

My 1964 AH-3000 is turning 40 next month, and regularly goes for months between startups. Since new, I have used SAE 30 diesel/gas rated oils in the car, switching to 15w-40 when it first became available back in the 70s. The car has 140,000 and something now, with as-new oil pressure, cam rotating the lifters as desired (no wear on the cam nose}, and a very clean engine. Judging from how hard it is to wash a 15w-40 off of engine parts, and hands, and given my low wear and lack of rust in this nearly antique engine, I'd say it must cling to surfaces during a long shutdown very well. I have had equally good luck with it in a variety of gas and diesel engines, from a 1951 Healey to Cat 3406s and motorcycles. For anyone interested,I use mostly Exxon XD-3 in 15w-40 year round, no starting problems in our mild winters.