Auto Repair 101 - Engines & Oil Changes

Auto Repair 101 Series - Engines & Oil Changes

Synthetic, conventional, 10W-30, and viscosity…. There are many confusing terms when it comes to engine oil.  Let’s clarify these terms and what they mean for your engine.

As a quick reminder, Bona Bros. is passionate about educating our Twin Cities customers so they can make informed decisions and have a better auto repair experience.  To do our part, our Auto Repair 101 Series dives into the various aspects of how your car or truck works. 

Our first article looked at the fuel system and how it powers your engine.  Now, let’s find out more about your engine lubricant and the in’s and out’s of oil changes.

Engine Lubricant

Your engine is an extremely complex machine made up of cogs, gears, pistons, seals, and the like.  These components are under extreme friction as they move against each other at high speeds.  With so much metal on metal contact, what prevents your engine from just wearing itself away?  Lubrication!

The engine you put in your car serves to lubricate these moving parts.  If tended to properly, engines can last hundreds of thousands of miles into old age.  Once we start exceeding oil change limits or not using the proper oil, these lubricating effects start to break down, gears erode away, and before you know it, your engine starts leaking and other downstream problems reveal themselves.

Choosing the right type of oil

Staying on top of your maintenance and getting regular oil changes is paramount, but how do we know which oil to use? 

Before we discuss viscosity and additives, always know that your owner’s manual will specify the exact type of oil to use for your engine.  The manufacturer of your car or truck knows the engine better than anyone else and will spell out which oil to use.  We highly recommend you follow their guidelines.

Viscosity

With that said, there are times when we might want to modify the type oil.  This brings us to viscosity, which defines how thick oil is under certain temperatures.  Motor oil becomes thinner as the engine runs and heats up and thicker as it cools.

Generally, a thicker oil produces a better lubricating barrier but may not necessarily flow to the many intricate components of an engine.  On the other hand, a thinner oil may have fewer lubricating properties but will likely bathe all of the internal components.

Choosing the right viscosity is therefore a balance between lubrication and speed of flow and is dependent on the outside temperature.

Most of us are likely familiar with terms like 5W-20 or 10W-30.  These are the naming conventions that specify the viscosity of oil.  The first number is a thickness rating of the oil at zero degrees Fahrenheit, the “W” stands for winter, and the last number stands for the thickness at 212 degrees Fahrenheit. 

The owner’s manual specifies the oil required under moderate temperatures but owner’s can change the oil to suit their operating environment.  For instance, a cooler climate may call for a 5W-30 instead of a 10W-30 or a warmer climate may call for a 10W-30 instead of a 10W-20.

Synthetic vs. Conventional Oil

Oils can be further broken down by whether they are conventional, full-synthetic, or synthetic blend. 

The different grades vary in their viscosity properties and their useful life.  Conventional oil is still in the industry but more and more we are seeing conventional motor oil being replaced by synthetic blends.  At Bona Bros., for example, our base oil change comes with a synthetic blend and we don’t even offer conventional oil.

The grade of motor oil also greatly determines when you should change your oil.  As always, refer to the owner’s manual to determine the type of oil to use and how often to change it.  Most will even provide the frequency based on which of the below oils you use.

Conventional:

This is the most basic motor oil available and comes in all varieties of viscosities.  There are typically few additives, if any, in conventional oil and car owners should be extra vigilant to stay on top of their oil changes as it can break down and turn into sludge within your engine.  At a bare minimum, we recommend this oil is changed every 3,000 miles or three months, whichever is sooner.

Full Synthetic

This is the most advanced motor oil when compared to conventional and is most often required for high-tech or heavy-duty vehicles.  This oil is packed with additives that maximize viscosity, lubrication, and have a long life span.  This is the most expensive oil but oil changes can go every 10,000 miles or 15,000 miles even.

Synthetic Blend

The synthetic blend is a highly recommended compromise between cost and lifespan that suits most newer vehicles on the road.  It has more additives and life extending properties than conventional and is cheaper than full synthetic.  We are seeing most manufacturers call for oil changes every 6,000 to 8,000 miles for this oil.

Additives

Beyond the type and viscosity, motor oils performance can be improved based on the use of additives.  There are many types with various benefits but here are some of the main ones:

Viscosity index improvers

Changes the thickness and flow rate of the oil

Detergents

Micro-particles that scrub clean the engine’s internal components and also prevent residue build up

Friction modifiers

Reduce engine friction so that fuel economy is improved

Foam inhibitors

Prevents the extreme temperature and speed of a running engine from turning the oil into a foam

Oil Filters

Just as important as using the right oil is making sure your vehicle has the correct oil filter.  Your oil filter acts as, well, a filter to capture deposits, sludge, and other material that can be harmful to your engine until it can be replaced by a new one.  The paper filter material and the o-ring gaskets wear away with use so it is vital that you always have your oil filter replaced with the type specified in your owner’s manual. 

A final word on getting your oil changed

The most important thing to remember when it comes to motor oil and keeping your car running is to follow the manufacturer’s recommendations as they are spelled out in your owner’s manual.  Use the right oil based on the operating temperatures where you drive and change the oil as it comes due.

If you are approaching the limit or have any other concerning issues, the expert technicians at Bona Bros. would be happy to take care of you.  Since 1956. we have been providing oil changes and other preventive maintenance for customers in Minneapolis and Saint Paul, Minnesota  Please don’t hesitate to call us today!