I obsessed over oil for about a year until I came away with some answers I could live with.
- main benefit of synthetic is a longer oil change interval
- synthetic also better for extreme climates; especially extreme cold (flows better on startup)
- synthetic doesn't cause leaks but can make a leak worse (seen it myself)
- modern conventional oils have modern additive packages and work well for modern 5-7k OCI
- there are different types of synthetic bases and some are still derived from petroleum and some are "lab made" (many brand name syn oils use more than one mixed together in their formulas)
- a Chevy 350 can run forever if you use conventional oil and a cheap filter as long as you change the oil on time
- modern oils do not have the right additive pkg for older flat-tappet engines
- modern Pennzoil doesn't contain wax LOL and is a quality name brand oil
- some vehicles require specially rated oils to maintain the warranty (e.g. DEXOS)
- if you read your manual, a lot of cars allow for other weights than the thinner oils on the cap (e.g. I run 5w30 over 5w20 in Oklahoma and the manual says I can based on the Oklahoma climate, regardless what the dealer says)
These are some of the things I came away with from my obsession/research. I switch things up some based on price, but I generally use cheaper conventional oil in my daily beater, cheaper synthetic in wife and step daughter's car (usually Tractor Supply or Atwood's brands), Sam's club house brand as top-off oil, and Mobil-1 in my personal nicer vehicle.
Take if for what it's worth, but unless you have an old Chevelle, you can probably just use whatever came in your vehicle from the factory (and choose whatever brand you want of that type of oil). Only exception is if you want to use a longer interval than is recommended for conventional (although many modern conventional oils are actually semi-synthetic).
- main benefit of synthetic is a longer oil change interval
- synthetic also better for extreme climates; especially extreme cold (flows better on startup)
- synthetic doesn't cause leaks but can make a leak worse (seen it myself)
- modern conventional oils have modern additive packages and work well for modern 5-7k OCI
- there are different types of synthetic bases and some are still derived from petroleum and some are "lab made" (many brand name syn oils use more than one mixed together in their formulas)
- a Chevy 350 can run forever if you use conventional oil and a cheap filter as long as you change the oil on time
- modern oils do not have the right additive pkg for older flat-tappet engines
- modern Pennzoil doesn't contain wax LOL and is a quality name brand oil
- some vehicles require specially rated oils to maintain the warranty (e.g. DEXOS)
- if you read your manual, a lot of cars allow for other weights than the thinner oils on the cap (e.g. I run 5w30 over 5w20 in Oklahoma and the manual says I can based on the Oklahoma climate, regardless what the dealer says)
These are some of the things I came away with from my obsession/research. I switch things up some based on price, but I generally use cheaper conventional oil in my daily beater, cheaper synthetic in wife and step daughter's car (usually Tractor Supply or Atwood's brands), Sam's club house brand as top-off oil, and Mobil-1 in my personal nicer vehicle.
Take if for what it's worth, but unless you have an old Chevelle, you can probably just use whatever came in your vehicle from the factory (and choose whatever brand you want of that type of oil). Only exception is if you want to use a longer interval than is recommended for conventional (although many modern conventional oils are actually semi-synthetic).
