Originally Posted by LeoStrop
Thanks for taking your time to go trough this!
My car doesn't have a catalytic converter, it is originally like that.
I briefly looked into the diesel options, but all of them are conventional oils. I thought maybe a semi was better?
Depends on what you're going to do. In a case where you're driving a vehicle with moderate performance I'm not sure there's much to be gained. If it was turbocharged or perhaps a high RPM engine, maybe something "better" might be an advantage. For the most part if you are performing manufacturer recommended oil change intervals there really isn't going to be much benefit. My wife's car is a 2002 Honda Civic, and I give it the cheapest "conventional" motor oil of the weight specified in the owners manual. If the manufacturer specifies something better (like GM's dexos or various VW/BMW/MB standards) then of course the best thing to do is follow those recommendations. I know some people take their vehicles on race tracks or perhaps try to extend their oil change intervals where maybe a "synthetic" might make a difference.
In your case if there's no catalytic converter then even heavy duty engine oils without a current API gasoline rating (like SN) would probably work. Possibly even work better than the most exotic synthetic oils. The big worry using them is a high phosphorus content damaging catalytic converters, and if you don't have that there's no issue using them.
The difference between a "conventional", "synthetic", and "semi-synthetic" oil are pretty much blurred. Even basic oils these days contain a lot of (chemically processed) Group II base oils that are better than older Group I oils from years ago that were only a product of refining/distillation.
Thanks for taking your time to go trough this!
My car doesn't have a catalytic converter, it is originally like that.
I briefly looked into the diesel options, but all of them are conventional oils. I thought maybe a semi was better?
Depends on what you're going to do. In a case where you're driving a vehicle with moderate performance I'm not sure there's much to be gained. If it was turbocharged or perhaps a high RPM engine, maybe something "better" might be an advantage. For the most part if you are performing manufacturer recommended oil change intervals there really isn't going to be much benefit. My wife's car is a 2002 Honda Civic, and I give it the cheapest "conventional" motor oil of the weight specified in the owners manual. If the manufacturer specifies something better (like GM's dexos or various VW/BMW/MB standards) then of course the best thing to do is follow those recommendations. I know some people take their vehicles on race tracks or perhaps try to extend their oil change intervals where maybe a "synthetic" might make a difference.
In your case if there's no catalytic converter then even heavy duty engine oils without a current API gasoline rating (like SN) would probably work. Possibly even work better than the most exotic synthetic oils. The big worry using them is a high phosphorus content damaging catalytic converters, and if you don't have that there's no issue using them.
The difference between a "conventional", "synthetic", and "semi-synthetic" oil are pretty much blurred. Even basic oils these days contain a lot of (chemically processed) Group II base oils that are better than older Group I oils from years ago that were only a product of refining/distillation.