Diesel lube oils for gas cars
Oils like the Delo oil are fine for gasoline cars. The duty requirements for diesels are typically more severe and oils which meet the SAE specs for diesels have no trouble meeting gasoline oil specs.
Of course you have some OEM specified oils for a few special cars such as BMW's new M5, which have viscosity requirements which may not be available in diesel spec oils. But for the vast majority of cases, a major brand diesel lube oil is fine for gasoline engines.
By the way, I have 292,000 miles on my 4 cylinder, turbocharged, '89 Mazda 626. I bought this car new, and I have changed oil and filters at 3K with dino oil. Never opened the engine, it has the original turbo. Still pulls original boost levels and uses less than 1 quart per 3000 miles - admittedly leaking here and there, rather than burning most of that amount.
Point being that if you stick with a good quality name brand oil and change it religiously, you can obtain excellent longevity of your engine without additives or without having to use synthetics.
That said, I do use Mobil 1 in my 500E!
in the engine business