What’s up with all the different motor oils these days?

Know which motor oil is right for your vehicle

The world of motor oils has changed in recent years. It used to be that you could pick up a 10W-30 for any vehicle and you’d be good to go – a 15W-40 oil was the standard for big rigs. Now, manufacturers are moving to all-synthetic type oils on the factory fill, and that’s causing confusion in the market. The bottom line is, you should always check your owner’s manual and use the oil weight that’s right for your vehicle. To demystify things, we’ll give you the low-down on what the numbers mean, what the difference is between motor oil varieties, and why that matters to your car or truck’s engine performance.

Motor oil types

When it comes to the right kind of motor oil for your car or truck, it’s all about viscosity.

Different engines, driving conditions, and maintenance levels require a different level of viscosity or resistance to flow. Hot environments will thin out the viscosity levels in oil, and colder ones will thicken it, affecting the oils lubricating function. The number before the W in the oil’s viscosity rating actually refers to “winter” not “weight” as many people think. The lower the number here, the better viscosity the oil will maintain in cold weather. The next two numbers indicate how the oil will function at high temperatures. A higher number here means the oil will perform better in hot temps than a lower number. Oil types include:

The W refers to performance in winter, not 'weight' as commonly though.'Conventional

  • A full petroleum-based product, this is the original motor oil
  • The least expensive oil option
  • A cost effective choice
  • Requires frequent oil changes
  • Best for low-mile, broken-in engines


  • A mix of conventional oil and synthetic oil, these blends are not regulated, so the ratio is variable
  • Better performance for heavier loads and higher temperatures
  • Not much additional cost over premium conventional


  • Added seal conditioners for vehicles with high mileage
  • Not effective for some engines

Heavy Duty

  • A combination of premium base oils and high-performance additives for diesel engines and fleets
  • Suitable for lower emission and older/conventional trucks


  • This oil offers the best performance at low and high temps
  • More frequently used for today’s high tech engines
  • Superior, longer-lasting performance
  • More expensive, but with significantly less maintenance needed

The movement to full synthetic motor oils

These days, cars and truck manufacturers prioritize fuel efficiency. By moving to a thinner weight oil, vehicles can realize better fuel economy by burning less gas – and oil. The thinner the oil, the less work the engine does, including burning less gas.

The thinner the oil, the less clearance for impurities in the engine. Engines are much more precise now, and a full synthetic oil has a much more consistent quality of performance for a more extended period over a conventional or blended oil. Chances are your new car or truck came factory filled with a 0W-20 or even a 0W-16 weight oil. On heavy-duty vehicles, manufacturers are filling trucks with a 10W-30 oil, even on big rigs.

While fully synthetic oils are more expensive, you’ll see a much better performance in your engine with a much less frequent need to change the oil – anywhere from 5,000 to 7,500 miles instead of every 3,000 miles like traditionally.

The right oil for your car, truck or fleet from Carson

If you are looking to have the confidence of the preferred brand and performance relied upon by the manufacturer, Chevron’s motor oil products are the best bet. For heavy-duty fleets, upwards of 70 percent of manufacturers are factory-filling their vehicles with Chevron Delo motor oil.

Contact Carson today at 503.224.8500 for the complete line of Chevron and Havoline motor oil products.