Oil weight

I have 3 cars; a 1983 MB 300D turbodiesel, a 1995 Camry XLE with 4-cyl and a 2002 Civic EX. I use Castrol because my Dad told me it was one of the best. The MB uses 20W-50, the Camry uses 10W-30 (high mileage) and the Civic 5W-20. I’d like to not have to keep 3 weights of oil. Do you think the MB and the Camry could use the same weight oil? And if so, what would you suggest? My Dad also taught me not to change weights, but if it were a small increment then I think he’d be okay with it. Also, if it helps, the MB only has 120k miles. The Camry about 190k. The Camry leaks some, but burns very little.

I’d keep the recommended weight.

20W-50 for the MB…that’s awfully thick…I’d hate to try to turn that engine over when it’s -10 or lower.

Check the owners manual if 5W-30 is OK in the Civic.
I’m not a fan of ‘high mileage’ oil.
15W-40 might be OK in the MB.
Starting a diesel at -10 is no fun regardless of the oil.

I would not use the same weigh in the MB and the Camry. It would either be too thin for the diesel or too thick for the Toyota.

I suggest using the recommended oil in each vehicle, and nothing else. It’s the best policy.

Castrol is good oil, but so are all the other brands, including store brands. You could save some money by using a less expensive brand.

I’ve been using store brand oil in all of my vehicles, regardless of mileage, for more than 20 years and never had an oil-related problem.

Yes, keeping three different types of oil on hand is inconvenient.
But, even more inconvenient is doing damage to an engine because you used the wrong viscosity oil.
Use what the manufacturer of each car recommends in the Owner’s Manual.

Stock one grade of oil and the cars will just have to deal with it. Your convenience is much more important.

I doubt that you are purchasing your oil in bulk quantities of 50 gallons. I think that having the manufacturer specified oil for each car is a minor inconvenience. Sometimes service centers that change oil in many vehicles use the “one size fits all” and stock only one weight of oil that is purchased in bulk. This is a good reason to avoid these businesses.

Where does dad come into it? Go by the owners’ manual for the vehicles. Is it that hard to keep an extra quart of each oil on hand for each vehicle? Really that’s all you should need once the oil change is done, even if you do them yourself. And since you can likely buy all 3 weights of oil at the same place-- again, what’s the problem?

I do think 20W50 is a little thick for winter use. If you don’t use synthetic, I’d consider a 15W40 Shell Rotella oil for the MB if the manual allows it–the truckers swear by it. If it gets cold where you’re at, I’d consider synthetics for all 3 though. With 3 vehicles, are you driving each of them enough that you’re doing more than 2 oil changes a year on each?

I keep 3 types of oil onhand for my Subaru, my snowblower, and a friend’s Toyota.
When I buy oil, I use a permanent marker to print “Subaru”, or “Toyota”, or “SB” on the side of the container. This way, I am unlikely to make a mistake if I am in a hurry.

I used to swear by Castrol. Now I swear by what meets the spec for my car and is on sale. I change my oil religiously and have never had an engine issue. My guilty pleasure is buying Walmart Supertech oil and grinning as I see how much money I save.

I use what the car manufacturer recommends. (not a brand of oil, but one that meets the specifications (weight and any other specification listed in your car’s owner’s manual)

The specification will likely be an SAE number starting with “S” for gasoline cars (spark) or “C” for diesel cars (Compression) Those letters and numbers define what specifications the oil is. Generally you can use a newer (higher) number but oil choices seem to be getting more complex as time goes buy.

Because times are tough, I swear by the store brand. It is far cheaper than the name brands, like Castrol, Valvoline, and Prestone, and it meets the same specifications.

Many thanks for the comments. Will stick with 3 weights and look again at the MB for my temperature range here in North Florida.