I use Valvoline 20-W50 VR1 since it has zinc. My engine only has about maybe 5K miles on it, I change it once a year (maybe 800 miles) and it doesn't use oil, slow any signs of trash or cause any other problems. I live in Southern Oregon where summer temps get 100+ daily and my car sees a good mix of freeway and city, even though it's limited mileage.
Simple answer for a change: Viscosity, 10-40 in the Summer, 10-30 in the Winter (if it’s driven, then). High mileage, Conventional. Penzoil High Mileage.
Run an HDDP Additive within the Oil.
Never go above 15/50Wt.
OE Filter, K&N, Mobil 1, etc.
You’ll find everyone has they’re own Oil preference, & despite the question is simple, answer is much more complex. I’ll explain.
Guessing this is relatively stock & you’re running a Flat Tappet Hydraulic, or Solid Cam. Not a Roller Cam-correct?
Do you have a Mech. Oil pressure Gauge?, if not, I’d recommend installing one.
Motor’s needs for Oil Wt. of is a combo of Both OE recommendations & Specifics of your engine & how it runs.
If you start it up after 24Hr’s & Hydraulic lifters clack away for a few minutes upon startup, low Oil Pressure at Idle when Cold, jump up a viscosity grade. Not more viscous than necessary, the components within the Oil are of equal importance.
Viscosity and Oil Type is Based on:
1) Bearing clearance setup. Mains-Rods.OE, or rebuild spec’s.
2) Achieving >/=25PSI at Idle, then 10psi pressure per 1,000 RPM up to 5,000 RPM’s, 50 psi.
3) What Oil type has been run in it, how often was it changed. Was it already converted to a Synthetic blend after the Rings were seated?
Independent of ANY of the above..
I’ve run ZDDP & Zinc additive(s) ever since ZDDP levels began to decline, flat Tappet Cam’s require minimum levels of ZDDP.
Best ZDDP Oil additive for classic car wear and tear from ZDDPlus and Cam Assembly Lube for cars and trucks to maintain top performance. Buy ZDDP Plus oil additive today
ZDDP has been an important additive to engine oils for >70 yrs, has an excellent track record at protecting the sliding metal-to-metal cam lifter interface by creating a film on cams and flat lifter contact points in response to extreme pressure and heat.
The film of zinc and phosphorus compounds provides a sacrificial wear surface protecting the base metal of the cam and lifter from wear. They’ve been removing it for Cat’s protection, large duration between Oil changes.
Synthetics are worth it if you have a strong, high mileage Motor, it’ll halt wear in the 90% range.
Some older, high mileage Motors May burn Oil as result of it, or old Seals May leak. It may be run providing the Viscosity and HDDP levels are present. If the Motors been taken care of across its miles, good Oil Pressure, no leaks, then it’s worth considering.
-Pennzoil is great, has adequate levels of HDDP, Detergent, Full Synthetic, Detergent type, HDDP is adequate, it’s made for High Mileage app’s. .
- Mobil 1 High Mileage Synthetic, 15-50 Wt. is required to get the HDDP levels, designed for high mileage, Detergent.
My OWN preferences:
- Amsoil or Valvoline, Quaker State, Pennzoil are what I run for Conventional Oil’s.
- Ford has their own Synthetics, I run that, Mobil 1, Royal Purple, Valvoline, Pennzoil for Synthetic Oil’s.
Run an OE Filter, Or K&N, Mobil 1. Makes no difference regarding Conventional or Partial/Full Synthetic Oil’s
Sorry for the dissertation, but there’s a lot to the subject, Type in Zinc, HDDP, view the importance in older app’s.
If you have any questions about anything I’ve listed, please- feel free to ask!