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What Motor Oil is Best for Winter? (And Other Cold-Weather Questions)

The Best Winter Motor and Transmission Oil Choice

Synthetic oil is best for winter.

We’re done here.

If only it were that simple. But most people want empirical data to support such claims.

Well, take a look at the video. We cooled a conventional 5W-30 motor oil and AMSOIL Signature Series 5W-30 Synthetic Motor Oil to -40º. As you can see, the conventional oil thickened so much that it barely flowed from the beaker. The AMSOIL product, on the other hand, flows almost immediately.

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Why the dramatic performance difference? In answering that question, I’ll also answer the question hoss61761 poses on social media:

Conventional oils contain waxes that solidify when the temperature drops. This severely impairs the oil’s ability to flow when you crank your engine. In some cases, the oil can thicken so much that it prevents the crankshaft from spinning fast enough to start the engine.

Prior to using AMSOIL, I had a Cutlass Ciera that was notorious for refusing to start on our cold Minnesota mornings. The dirt-cheap big-box-retailer oil I used back then thickened so much the engine would barely turn over.

Why synthetics flow better in winter weather

Synthetics, in contrast, don’t contain waxes due to the chemical-reaction process used to construct synthetic base oils. As a result, synthetics demonstrate far better cold-flow properties than conventional oil. Not only will your vehicle start more easily (I’ve yet to have one of my vehicles using AMSOIL fail to start, even with temps pushing -30ºF), the oil will flow more quickly, ensuring oil reaches vital components faster. This, in turn, maximizes wear protection, helping your engine last longer.

Check the oil’s pour point

If you want more data to prove synthetics’ cold-weather superiority, check the oil’s Product Data Sheet. Look for the oil’s pour point. Lower numbers indicate better cold-flow, thus better cold-weather performance.

In the example here, you can see that AMSOIL Signature Series 5W-30, the same oil shown in the video above, has a pour point of -58ºF (-50ºC).

What is cold?

Not to get existential here, but it’s a relevant question. Folks in the south whose idea of winter is putting shoes on for a couple weeks in January may think they’re off the hook. Do they need to waste mental energy on motor oil cold-flow properties?

Good cold-flow is important to Southerners, too. Here’s why.

Engineers agree that most engine wear occurs during cold starts. There are several reasons, but two concern us for this discussion:

  • Gravity causes much of the oil to fall back into the oil sump, leaving components unprotected
  • Cold oil doesn’t flow immediately at startup, temporarily starving the engine of oil

While true that oil thickens more in sub-zero winter weather and causes increased starting difficulty, an engine is considered “cold” after it’s sat long enough to cool to ambient temperature, typically overnight.

The oil inside your engine cools as it sits overnight. As it cools, its viscosity increases (it thickens). When it’s time to start your vehicle in the morning, the thicker oil doesn’t flow through the engine as readily as it does when it’s at operating temperature. It’s during this time that vital engine parts can operate without lubrication, increasing wear. So, even in warm climates, cold-start wear is a problem. Southerners are well-advised to use a good synthetic oil with excellent cold-flow properties, too.

Thick or thin oil in winter?

Motorists sometimes ask if they should use thicker or thinner oil in the winter. Fortunately for them, we wrote a whole post on that topic. Check it out here.

Should I Switch to a Lighter Viscosity Oil in Winter?

To summarize, use the lowest viscosity oil your vehicle manufacturer recommends in the winter. Most automakers recommend a lone viscosity year-round. But some allow you to switch to a lower viscosity in winter, which helps improve cold-flow.

If your owner’s manual says you can switch to a lower viscosity oil in winter, go for it.

Shift to better winter protection

While I have you here, I should talk about transmission fluid, too. Like motor oil, it thickens in cold weather. The cold, thick fluid doesn’t flow readily through the intricate network of passageways in the transmission valve body or through the small solenoid openings. What does that mean to you?

  • Delayed shifts
  • Elongated shifts
  • Hard/harsh shifts
  • Reduced wear protection

Cold, thick transmission fluid doesn’t flow readily through narrow valve-body passages, leading to poor shift quality.

Again, I’ll go to the well of personal experience. After buying a Honda CR-V several years ago, I switched to AMSOIL synthetic motor oil…but I neglected to change the transmission fluid. Fast-forward to winter and one of our trademark -20ºF mornings with a wind chill pushing past -40º. The Honda started, but she shifted slowly and with much wailing and gnashing of teeth. The entire vehicle shuddered as it reluctantly found second gear heading down the road.

Switching to synthetic transmission fluid solved the problem. The fluid flows much more readily in the cold, which translates into smoother shifts. It also means the gears and bearing are receiving vital lubrication, too. Anyone who’s shelled out thousands of dollars for a tranny replacement knows how important that is.

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Bottom Line: Synthetic motor oil and drivetrain lubricants perform better in the cold than conventional oils. They flow better for easier starts, smoother shifts and better protection against wear. Upgrade to synthetics to maximize cold-weather protection and performance.

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What to Know When Choosing a Fork Oil

When is the last time you changed shock oil?

Fork Oil – Which do I use?

We sell a good amount of fork oil in Sioux Falls thanks to some great motorcycle shops who know how to maintain the various units out there. But if you have a shop manual, the right tools and some patience give it a try!  Some units are very simple, quick and easy.

A fork oil’s number-one task is to deliver consistency. Consistent dampening despite temperature changes. Consistent rebounds despite different terrain. Consistent performance so you can ride or drive confidently.

Consistency.

What fluid would provide the best shock consistency?

Water.

Yes, water. But you don’t want to use it in your shocks for reasons you can probably guess, but we’ll get to that in a bit.

What shocks do

The shocks on your dirt bike, race car, ATV or other vehicle absorb abnormalities in the terrain and help stabilize the ride. They also absorb impact when landing a jump, taking some of the beating off the vehicle and your body. And they “load up” with energy when approaching a jump, helping you fly over whatever’s in your way.

The shock uses fluid to control dampening and rebound.

Say you’re riding your dirt bike and land a jump. The force depresses a piston inside the shock that pushes fork oil through calibrated valves. The fluid’s rate of flow through the valves influences the amount of dampening and rebound.

A thin fluid flows faster and results in quicker, springier shock feel. In contrast, a thick fluid flows more slowly and results in slower rebound and stiffer shock feel.

Fork oil viscosity matters

The fluid’s viscosity (often thought of as its thickness) influences how fast or slow the oil flows through the shock valves. If you prefer quick rebounds, use a lighter fluid. If you like slower rebounds, use a heavier fluid.

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Easy, right?

Sure, if the viscosity of the shock oil never changes.

However, cold ambient temperatures increase the oil’s viscosity, resulting in slower rebounds. Then, after you’ve made a few laps and the vehicle’s heated up, the fork oil thins as it warms. That’s because fluids become thinner when they warm up. Think of molasses or honey. The warmer oil flows faster through the shock valves, leading to inconsistent shock feel.

H2O, no

That’s why water theoretically would provide the most consistent shock feel. Its viscosity doesn’t change between 33ºF (0ºC) and 211ºF (100ºC).

On a cold morning, after a long ride or on a blazing-hot day, water maintains the same viscosity provided it doesn’t freeze or boil. When was the last time you had a thin or thick glass of water? Hence, it would flow at the same rate through the shock valves, resulting in consistent feel.

Much more than flow, though

But the fork oil must do more than influence rebound and ride feel. It also must protect against wear and corrosion, two tasks at which water is notoriously bad.

The shock oil has to protect the shock tubes, seals and valves from wear as they constantly rub together. Minus good wear protection, the shock would tear itself apart in short order. Plus, the oil must form a layer on parts to prevent formation of corrosion. If corrosion starts, it won’t stop, spreading and depositing flakes of contaminant in the oil that act like sandpaper and scour metal parts until they’re worn out.

Look for a high-VI fork oil

Instead, look for a fork oil with a high viscosity index (VI). A higher VI indicates better resistance to viscosity changes throughout broad temperature swings. That translates into consistent shock performance and feel despite the ambient and operating conditions. And a consistent ride equals a more effective rider.

Points to consider when looking for fork oil

1) No standard viscosity

Your engine manufacturer recommends a specific viscosity of motor oil for best protection and performance. In the world of shocks, there are no universal viscosity requirements or recommendations. Each shock oil manufacturer is free to formulate its oils to whatever viscosity it deems appropriate. That means one brand’s “light” fluid could behave like another brand’s “medium” fluid, and so on.

2) Once you find a shock oil you like, stick with it

For the reasons listed above, avoid switching between fluids if you can. Once you have the proper suspension set-up for your body weight and riding style, stick with it. The shock oil is one of the biggest variables in your suspension tune, and messing with it can throw off suspension feel and your riding confidence.

3) Look at viscosity at 40ºC

If you decide to switch shock oil, compare the viscosity of the fluid you’re currently using at 40ºC to the same data for the new fluid. The closer the results, the more similar the oils will perform. Reputable manufacturers publish product data bulletins for their shock oils and post them online. If you can’t find a data sheet for the oil you’re considering, think twice before using it.

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How to Clean a Gun for Hunting Season

gun barrels image

How to Clean a Gun for Hunting Season

Fall is fast approaching, which means if you’re an avid hunter, you’ve already been out kicking the bush testing your skills. Because I work during the week, I suppose I can be considered a weekend warrior – not too uncommon among us hunting kind.

That said, you never can plan great weather on the weekends, so we play the hand we’re dealt. At times, depending on what I’m chasing, bad weather is music to my ears. No matter what you are up to or when you do it, there is one thing I can promise: a successful hunt begins with a properly operating gun.


Don’t make the mistake of neglecting your most useful tool, as I did a few years ago on a goose hunt in Iceland, which left me frustrated and cussing. Two things will undoubtedly happen at the worst time: click and no bang, or the security you thought you had in that second or third shot of your semi-auto vanishes, leaving you with a single-banger.

Not good when the geese are coming in droves.

Fortunately, I corrected my faulty actions in Iceland simply by cleaning my shotgun. Yes, it was as simple as that, and I was back up and firing dependably.

Hunting is supposed to be relaxing and fun – don’t make it stressful. Clean your gun! Keep reading and I’ll give you a few tips on the cleaning process.

How to clean a gun

Like I’ve said in the past, I’m not a professional hunter or gunsmith. I’m just an everyday guy who likes to pull the trigger. So, my methods are my methods, which may not be your methods. Everyone is different. We all may use different rods, patches, rags, solvents, lubes, etc. In the end, however, what I strive for is a clean, dependable firearm. Probably not too far off from what you hope for in your firearm.

The following tips are based on personal success, not the success or methods of others. While we all have opinions, I think we can all agree that your firearm will be happier if you clean it using this process.

1) Make sure your gun is unloaded

The first and most critical step. People die every year cleaning a gun they thought was unloaded. Don’t be that person. Double check and make sure the chamber is empty. If the gun holds extra rounds, remove them.

2) Have all the tools you need available

I recommend the following:

I’m a little biased toward the cleaner and lubricant I use since I helped develop these products and I know they work. You may choose another brand and like it. That’s great; but think about giving these two products a try. You won’t be disappointed.

Buy AMSOIL Firearm Products

3) Disassemble your gun

Now that we have all the tools we need, let’s get down to business.

I like to completely disassemble my guns. Sure, if I’m in a rush, I’ll leave them together, but to really clean a gun inside and out, you have to take it apart. Reference your user’s manual since it typically provides instructions on disassembly for cleaning. If you are unsure or worried about putting it back together correctly, leave it assembled.

4) Clean the barrel

I start with the barrel. Spray the inside with solvent. Let the solvent soften the residue and wash it out the end of the barrel.

Then, attach a clean rag to your cleaning rod and run it down the barrel a few times. The rag will help remove residue. Look down the barrel and see if it is shiny and smooth. If you haven’t shot much, it may require minimal cleaning. But, often you have to work a little harder to clean it.

Take the dirty rag off the cleaning rod and attach the bore brush. Spray the inside of the barrel again and run the bore brush through the barrel a few times. Remove the bore brush from the cleaning rod and run another rag through the barrel.

Look down the barrel again. It should be smooth and shiny. If not, repeat this process until clean or until you can run a rag through the barrel and have it come out clean. Once the inside of the barrel is clean, run a clean rag dampened with lubricant down the barrel. I use AMSOIL Synthetic Firearm Lubricant and Protectant. This leaves a thin film on the inside of the barrel as protection against corrosion.

The picture on the left shows a shotgun barrel after firing 100 rounds. The picture on the right shows the same shotgun barrel after being cleaned with AMSOIL Firearm Cleaner.

5) Clean the action

Depending on your gun, the action may include several moving parts, and they’re often coated with powder residue. This area is the source of most misfires or jamming issues.

Clean each component of the gun’s action with the same solvent used to clean the barrel. Use a clean rag soaked in solvent to wipe each component clean.

Once clean, dampen another clean rag with lubricant and wipe each action component. The lubricant in this area does multiple jobs. It protects from corrosion and provides the necessary lubrication the action components need as they slide against one another. Without lubricant here, the firearm is exposed to wear, reducing its life and dependability.

AMSOIL Specializes in the one aspect no other addresses: Rust protection beyond expectations. That goes for our classic car formulations and antifreeze.

6) Reassemble the gun and lubricate external surfaces

Wipe the outside of the firearm with a clean rag dampened with solvent to remove any powder residue, dirt or oil left by your hands. Once clean, take another clean rag dampened with lubricant and wipe all the surfaces. This helps protect the external surfaces from corrosion.

This process is not all-encompassing. It’s possible your user’s manual provides additional cleaning recommendations. Either way you slice it, your gun should be clean, well-lubricated and more dependable than it was before your cleaning process.

I can’t take responsibility for issues resulting in the improper reassembly of your firearm. Like I said, it’s best to know how to put it back together before you take it apart. Or, call your local gunsmith and he’d be happy to help.

Remember, hunting is about reducing stress and coming home with your day’s limit. Don’t let a dirty gun get in the way of that effort. Best of luck hunting this season. Be safe.

Product available in Sioux Falls at Stan Houston’s and the AMSOIL location at the Tea Exit.

400,000 Mile BMW and 20 YEARS Thanks to AMSOIL

400,000 mile BMW uses only Amsoil

AMSOIL KEEPS BMW ON THE ROAD FOR NEARLY 20 YEARS

400,000 mile BMW uses only Amsoil

For more than 18 years, Preferred Customer Ilya Moshenskiy of Redmond, Wash. has trusted AMSOIL synthetic lubricants to keep his 1998 BMW on the road.

“I’m a long-term customer. (I’ve) personally put over 400k miles in the driver seat,” Moshenskiy said. “I have owned my 1998 BMW 528i* for over 18 years. It’s still in the condition I remember it being when I first drove it off the dealer lot. Since day one, I have been doing my own oil changes exclusively using AMSOIL.”

Moshenskiy said he depends on the car in all conditions.

“My car has been a workhorse getting me through thick and thin,” he said. “Over the years, the 528i has been a reliable family member. It has given us countless memories over the past two decades, from the sunny beaches of San Diego to pummeling through two feet of snow in British Columbia, Canada. I know whether I’m commuting or taking it on the next road trip, my 528i will get me there. My only worry are those pesky tail light bulbs that burn out with age.”

Moshenskiy spreads the word about the AMSOIL European Car Formula that has kept his BMW running for so many miles.

“Every time I start a conversation about 400k miles on the original motor, people ask what’s the secret,” he said. “AMSOIL is the secret; It’s a synthetic which actually is synthetic, that’s what you need to know. I don’t think I could have logged over 400k miles if it wasn’t for AMSOIL. Believe it or not, this is still my daily driver.”

Not only is the car still his daily driver, it looks like it’s new.

“There’s something about thick German paint that lasts long and looks new,” Moshenskiy said. “I’m in Seattle and have taken the car on many trips in the Pacific Northwest and Canada.”

See Our Favorite Bikes from the 2019 Sturgis Motorcycle Rally

sick bike at Sturgis

See Our Favorite Bikes from the 2019 Sturgis Motorcycle Rally

Sturgis.

For decades it’s been the rallying cry of bikers from across North America. Riding in the Black Hills of South Dakota quickens your senses and offers an elixir for the soul. So say the hundreds of thousands who pilgrimage to the Mecca of the motorcycle world every summer.

First held in 1938, the Sturgis Motorcycle Rally has grown from a small gathering of enthusiasts to the premier biker event of the year, attracting half a million riders to Sturgis, S.D. each summer.

As Official Oil of Sturgis, AMSOIL maintains a huge presence around town, including a corporate booth, where enthusiasts can learn about the entire AMSOIL product line and find out how to purchase AMSOIL products at wholesale pricing.

On display in the AMSOIL booth this year were bikes from Confederate Motorcycles as an introduction to our partnership with them.

Check out the bikes Team AMSOIL fell in love with during the 2019 Sturgis rally below.

Pabst Blue Ribbon Motorcycle Sturgis